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Do you have questions about climate change?

From MLK in Michigan

Climate is like the weather but on a MUCH longer time scale.  The weather changes over the scale of hours and days.  Climate changes on the scale decades and centuries.   So just like weather, the climate is always changing.  The difference with the current change in climate is that for the first time ever, humans are the primary cause of climate change.  If humans were not putting carbon dioxide and other greenhouse gases into the atmosphere, the climate models tell us that the climate would be getting cooler, not warmer! (From Steve McNulty, director of the USDA Southeast Climate Hub) 

Clouds act like an umbrella that blocks sunlight from shining on the Earth.  Therefore, clouds can cool the Earth and reduce global warming.  Clouds can be generated from water vapor.  The oceans produce a lot of water vapor and as they warm, they will likely produce more water vapor and clouds.  This will help to slow down global warming a little, but the warming caused by increased CO2 will greatly outweigh the cooling impacts so the overall result will be more global warming.

Dr.Steve McNulty,PhD

Director,Southeast Region Climate Hub





Deke Arndt from NOAA's National Climatic Data Center here ... yes, climate change will have an impact our children. I have two at home myself. But I also know that our children will have an impact on climate change. And we are going to be proud of what they accomplish. All of us, children and adults, can start work right now to help the next generation get a head start on dealing with the climate they inherit.

Hi Sarah,

That’s an excellent question! You’re correct that vegetation, like trees and lawns, absorbs CO2 and can help offset some of our fossil fuel emissions. It is estimated that growth of forests in the United States help offset about 16% of annual fossil fuel emissions (http://www.fs.usda.gov/ccrc/topics/forest-carbon). That’s no small contribution. Keeping forests forested or converting deforested lands to forest are the main things that can help with carbon storage. How to manage effectively to enhance the amount of carbon stored by vegetation is an area of active research in the US Forest Service and in many other agencies and universities. Unfortunately, there is not an easy answer about how to do this. Quick-growing plants and trees do have a rapid rate of carbon absorption, but many of those quick growers tend to be short-lived and release carbon dioxide when they die and decompose or when used as biofuels or products such as paper. The relative balance will vary from place to place.  

As for what you could do in your own back yard, some colleagues of mine did a study in suburban Minnesota to understand the relative contributions of different vegetation types like grass, evergreen trees, and deciduous trees (http://onlinelibrary.wiley.com/doi/10.1029/2011JG001933/full). What they found is that evergreen trees absorbed the most carbon, followed by deciduous trees, and then grass was a far third. Grass absorbed more carbon when it was watered, but they did not look at different mowing frequencies. This study was only for one place, so it is difficult to extrapolate to where you live. It’s also important to remember that urban and suburban areas make up a very small proportion of our total land base, so they make a relatively small contribution to the carbon cycle.

Even if the contribution of your yard to offsetting carbon emissions is small, sustainably managing your yard can be good for many reasons. Reducing the amount of pesticides and fertilizers  can help reduce water pollution. Only watering when needed can help conserve water in areas where water resources are scarce.

Leslie Brandt

Climate Change Specialist

US Forest Service

Leslie Brandt here. It's true that other countries are also contributing greenhouse gas emissions, but that doesn't mean we shouldn't be part of the solution.

If you saw someone littering, would you say, "It’s OK. Now I can litter too."? I hope not! If it were me, I would set a good example by not littering and explain why it is important not to litter. Greenhouse gas emissions are the same way. China has been listening and has now developed a plan to greatly reduce their CO2 emissions. I hope we can follow their lead!


Steve Mc. US U.S. Forest Service

"First let’s clarify that China is not largely responsible for climate change, even though its CO2 emissions are now largest. Climate change is proportional to cumulative emissions. The fact that most early historic emissions are no longer in the atmosphere – having been distributed among the ocean, atmosphere, soil, and vegetation reservoirs – is almost exactly compensated by the fact that the early emissions have operated longer on the climate system."

"The United States bears 27% responsibility for cumulative emissions. China is second at 9.5%. On a per capita basis, the United States is more responsible than China by about a factor of ten." (by James Hansen)

Remember that once a fossil fuel is burned and the carbon dioxide emission enters the atmosphere, it stays there for a very long time. How long do they stay in the atmosphere? Each of these gases can remain in the atmosphere for different amounts of time, ranging from a few years to thousands of years. All of these gases remain in the atmosphere long enough to become well mixed, meaning that the amount that is measured in the atmosphere is roughly the same all over the world, regardless of the source of the emissions.


Great question! As the earth increases in temperature, it can hold more water. This means that as a whole, we should receive more precipitation. However, there will be a lot of geographic variation, with some areas getting wetter and some drier.

-Leslie Brandt

Hi, Deke Arndt here. The answer is yes! Precipitation, and all weather, is influenced by long-term changes in the climate system. A warmer atmosphere can not only "hold" more water vapor (the stuff that precipitation is made of), it can also "demand" more water vapor from the surface in the form of evaporation. An atmosphere that carries around more water vapor can deliver more rainfall when that happens.

Hello Craig,

The scientific consensus is that natural changes in the sun’s energy and from volcanic eruptions have a very small effect on global temperature compared to human-caused changes. Scientists estimate that natural causes have probably led to fluctuations in global temperature of approximately plus and minus 0.2° C, (averaging to about zero), while human influences have contributed roughly 0.8° C of warming since 1889. A really nice summary of these relative contributions can be found here: http://earthobservatory.nasa.gov/Features/GlobalWarming/page4.php

To answer the second part of your question, we know that the ozone hole is new because scientists began measuring ozone over Antarctica in the 1950s and the amount of ozone started declining over the course of the measurement period. You can find out more here: http://ozonewatch.gsfc.nasa.gov/facts/history_SH.html

Leslie Brandt

Climate Change Specialist

US Forest Service

That a great question. Good examples by Dr Don and the other post. This gets pretty complicated and interesting once you consider all the possibilities. Climate change can change biodiversity at the individual, population, species, ecosystem and even biome levels. In a technical sense, four key areas have been researched: 1) physiological effects (how will the normal functions of a plant or animal be effected?) ; 2) phenological effects (how will a plant or animal’s seasonal cycles be effected?); 3) distributional shifts (how will a plant or animal change locations where it can thrive?): and 4) interspecific interactions (how will plants and changes change when other plants and animals around them change?). A key climate change concept is that individual plants and animals will respond to climate variation independently, uniquely, and on differing time scales. 

So… all of this together this will create a species behaving differently, some doing well, others suffering unless they can move around. And we’ll seeing new mixes of species. How it all works out is a real unknown, and a change in one population, species, or a whole family of species can trigger complex “cascading” effects to others...

David Patte,

U.S. Fish and Wildlife Service

As with all things, there are those that may benefit from climate change and those that will not benefit. If you live is a cold area, longer growing seasons and warmer temperatures could mean more plant growth (in gardens and in forests). The down side is that it can also mean more droughts, and wildfires. Unfortunately, there is a lot more bad parts of climate change than there are good parts.


Steve Mc. USDA

U.S. Forest Service

Yes. There is something called an urban "heat island." The dark, impervious surface absorbs heat. In suburbs, trees and other vegetation help keep the area cooler.

Check out: http://www.epa.gov/heatisland/

-Leslie Brandt

Hi Maria, Deke Arndt from NOAA's National Climatic Data Center here. Yes, very urban areas tend to be warmer than less urban areas, especially on and following very sunny, calm days. Much of the "built environment" (buildings, roads, infrastructure, and so on) holds onto heat much longer than natural surfaces, which means the overnight hours will trend warmer.

This is actually one of the factors we correct for in the data sets we use to track the long-term warming of the planet and our country!

 Shawn An,

Noise and light pollution are serious issues, especially in busy urban areas, but they do not contribute to climate change. Climate change is caused by changes in greenhouse gases in the atmosphere. Sound and light are waves, and are not gases. Noise pollution is sound that is loud enough that it is harmful to human and animal health or well-being. Likewise, light pollution is artificial light that, when combined, disrupts the natural night sky and can be disruptive to human and animal sleep cycles. Although noise and light pollution are not the same things as greenhouse gas emissions, we all contribute to the problem, and thus we can all take steps to reduce our impacts. Turning down your music or practicing your drum set with your doors and windows closed can help reduce noise pollution. To reduce light pollution, consider replacing your outdoor lights with low-glare alternatives and install motion sensors so lights are not on when not in use.

Leslie Brandt,

Climate Change Specialist,

U.S. Forest Serviceand

Northern Institute of Applied Climate Science

Hi Jos. Kurt Johnson here. If climate change continues, things will be very different in many areas. Summers are likely to be hotter, perhaps very much so. Winters will be warmer. Rainfall patterns will change, so some areas will be wetter, others drier. Some areas that now get a lot of snow will get more rain instead. Storms may become more intense. Future climates in many areas may not be very recognizable!

One thing is for sure, weather is always changing! Even if our climate does not change, we will always see variation in the weather we experience from day to day.

-Leslie Brandt

Who said the world is supposed to be getting colder? I have never read such a thing. The world does become warmer and colder naturally, but that takes many thousands of years. The climate change we see now is happening in decades and because it is so fast, it's causing lots of problems.

Steve Mc. USDA U.S. Forest Service

LuAnn responds: I think the Webcast had a section saying that if Earth followed the long-term natural cycle we've deduced (four ice ages over the last 400 thousand years), you would expect the global climate to be getting colder soon. The fact that it's getting warmer instead of colder was presented as evidence that what we are seeing is not part of a natural cycle.

The hole in the ozone layer is another important issue, but the main area of concern there is an increase in UV-B radiation, which increases our risk of skin cancer and can have negative effects on some plants.

No. There are different gases called CFCs (long name to spell out) that recreate the ozone hole, but those are also a pollution problem.

Steve Mc. USDA U.S. Forest Service

Sure. Lots of times. If an asteroid hits the Earth, lots of dust and ash is thrown into the atmosphere. This can block the suns light, and make Earth much colder and darker for many years. On a lesser scale, volcanoes can also cause random climate change. 1816 was called the year without a summer because a large volcano exploded and blocked out sunlight. It even snowed in the middle of summer!


Steve Mc. US U.S. Forest Service

Probably Alaska, but you can check out http://www.epa.gov/climatechange/impacts-adaptation/alaska.html to see what is happening where you live too.

Steve Mc. US U.S. Forest Service

Leslie here. In the continental US, the northern great lakes and the southwest have been experiencing more rapid warming than the country as a whole. Check this out: http://www.climatecentral.org/news/the-heat-is-on

Dr Don here from Smithsonian's National Zoo. I think there is some really good information on regional effects of climate change at the Smithsonian exhibit "Forces of Change" at http://forces.si.edu/index.html

This is a great question, and like most great questions, there is a lot of complexity underneath. Folks in New York, New Jersey, Louisiana and Mississippi might argue that sea level rise contributed to more severe storm surges in Sandy and Katrina. Folks in North Dakota might say, "Hey, we're warming more than any other state in the contiguous United States!" Folks in Alaska might say, "Wait a minute, we're losing permafrost and that means we have to rebuild a lot of what we thought was safely frozen in the ground." Folks in the West might say, "Hey, our snowpack is decreasing. We need to drink that stuff!”

Great question Adam. Microbes in the compost can actually create heat from their metabolic activity. So your compost bin can be alive and kicking even when it's cold!

-Leslie Brandt

Leslie Brandt here. One of the things New York is doing is its Million Trees NYC campaign. Trees help take up carbon dioxide and can reduce the urban heat island effect.


Dr Don here from Smithsonian's National Zoo. Great question Brooklyn! I used to work in Prospect Park in Brooklyn, so I know you guys in New York City already do a LOT to help with climate change. You ride public transportation more than almost any people in the world, so your carbon footprint as you go to school, the beach, or the store is already low. You can also grow your own vegetables in your backyards or on the tops of apartment buildings, or even work with public city gardens to grow those veggies! You can help by planting new trees in your parks, because green spaces in cities help a lot. You can form an in-school energy audit team to help the school save on energy use (and save money!). Thanks for helping!

Hi! This is Kurt Johnson USFWS. New York City has a climate change plan. You could get a copy of that and learn about the plan and what you can do. Here is the link:


One thing you can do is help create greener communities by planting trees where possible, developing local community parks, etc. It's quite a challenge, but you CAN make a worthwhile contribution. Good luck!

Well Tyler, if everything stays the same, our weather will more or less stay the same. But if by stay the same, you mean we do not do anything about climate change, then the weather will be warmer and more extreme with more heavy rains, floods and droughts. That does not sound very good does it?

Steve Mc. US U.S. Forest Service

Hi Tyler! Deke Arndt here. I'm going to go out on a limb and assume that "everything stays the same" means "we continue to artificially warm up due to greenhouse gases." Please let me know if I'm incorrect on this!

The short, short version is that most places in the world (and the US) will see more Big Heat events (like longer, or more intense or more frequent heat waves), fewer Big Cold events (for example, the type of cold we experienced in the Eastern US this year used to occur more often), and more Big Rain (meaning that the rain we get over the course of a year will be more and more delivered by heavy rains as opposed to moderate rains, and for much of the US, the big rain events are getting bigger), and to some extent, more Big Drought.

Violent weather, like tornadoes and severe thunderstorms ... there hasn't been a real distinct change observed so far, and some of the ingredients that go into these events are moving in opposite directions. That's still a very active area of research!

Dr Don here from Smithsonian's National Zoo. We probably don't even know how many species or individuals are being harmed. There are very visible declines in body weight and population in polar bears and other arctic animals, due to loss of their sea ice habitat during this warming climate. Insects that emerge due to warm temperatures are now out-of-sync with the plants they depend on, because the plants become active based on winter length or light conditions rather than spring air temperatures. Cold water fishes are declining in some areas due to warmer waters. And animals in areas that are wetter or drier than they have been over the last several thousand years may also be affected. If we help reduce our human impacts on the environment we can help these animals.

Good question but no one knows. Change is hard on animals, so the more change, the more potential for animals being hurt. The World Wildlife Fund has some good information on climate change impacts on animals. http://wwf.panda.org/about_our_earth/aboutcc/problems/impacts/species/

Steve Mc. U.S. Forest Service

In 2013 some researchers published a paper on which species of birds, amphibians and corals are most vulnerable to climate change. They found that 24-50 % of birds, 22-44 % of amphibians, and 15-32 % of corals were highly vulnerable to climate change. These are pretty astounding numbers! But again, these are just the species they say are vulnerable to climate change, not necessarily those that are already being affected. Here's the paper if you want to take a look: http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0065427

Carbon offsets can help take up some of the carbon dioxide that is emitted from another activity elsewhere. Carbon offsets can include things like reforesting areas or avoiding deforestation. The idea is that forests serve as "carbon sinks" and help take up carbon dioxide.

-Leslie Brandt

Carbon offsets are an attempt to keep the amount of atmospheric carbon dioxide from growing. Industries that produce carbon dioxide as a consequence of their actions can pay other people to plant trees or maintain wetlands that "absorb" carbon dioxide, thus offsetting the emissions of the first business.

-LuAnn Dahlman

Natalie, the climate influences what food can be grown in particular areas, what outdoor recreation activities we engage in, what materials we use to build our roads, and many other decisions.

-Leslie Brandt

Abby, the long-term stability of carbon dioxide in the atmosphere makes it very unlikely that we will return to the atmosphere Earth had before the Industrial Revolution. We are already committed to further warming, but the smaller our future emissions of heat-trapping gases, the less warming we'll see.

-LuAnn Dahlman

Some people who live along the coasts are working to build seawalls for protection or lift homes above their current levels. In some cases, people choose to move to higher ground.

Kurt Johnson here from US Fish and Wildlife. That's a tough question, especially in the developing world where millions of people live close to the coast and will be displaced by rising seas. Entire island nations such as Maldives and Kiribati are threatened by rising seas, which will essentially cover all the islands. Here in the U.S. sea-level rise will have a substantial economic impact, especially on areas that have houses and other buildings close to the shore. We need to continue planning for sea level rise and the impacts it will have on communities and economies. Many places in the U.S. and around the world are already doing that, but this planning needs to continue. The world community needs to recognize the threat and make a commitment to help those areas most likely to be affected.

Charlotte from Metrolina Regional Scholars Academy

Hi there! Deke Arndt here. We've already put enough greenhouse gases in the atmosphere that we've changed the climate for many lifetimes in the future. So, it's not fixable in the sense that we can put it back to where it would have been without the artificial warming we've added.

It is still fixable in the sense that we can take actions - by ourselves and with our neighbors - to slow and stop the addition of heat-trapping gases. Doing this means we will have fewer and less-expensive problems down the road.

We have already altered our atmosphere and some degree of climate change will occur even if we dramatically reduce our emissions. However, we can take steps now to reduce the amount of warming by reducing our greenhouse gas emissions.

-Leslie Brandt

Leslie Brandt here. Good question. Agriculture actually contributes about 8% of total US greenhouse gas emissions. http://www.epa.gov/climatechange/ghgemissions/sources/agriculture.html

There are lots of ways agriculture can reduce greenhouse gas emissions. Here’s a summary by Iowa State University Ag. Extension: http://bit.ly/1gqa3nc

David Patte, U.S. Fish and Wildlife Service

Hi Nicole, Deke Arndt here. Yes, the wind is driven by "gradients" in pressure. A gradient means a change from one place to another. This driving force even has a name in meteorology: the Pressure Gradient Force (or PGF). The PGF is what initiates the wind.

When you squeeze your tube of toothpaste, you are applying high pressure to one end of the tube, and there is relatively lower pressure at the nozzle end. You've just created a pressure gradient! And the PGF that you made forces that fluid (the toothpaste) to move from high pressure (the end you squeezed) to low pressure (right out the nozzle).

In the atmosphere (also a fluid, just not as goopy as toothpaste), wind is driven the same way. It is originally caused by PGF. It gets steered around by various other forces.

Also, just like the toothpaste tube, the stronger the pressure difference, the faster the fluid moves! This is why storm systems with "deep low pressure" often have the strongest winds.

Even when the earth has experienced dramatic changes in climate in the past, some organisms have survived. Therefore, we expect some species to adapt to changes and survive into the future. However, many species may not be so lucky, including those we rely on for our own survival.

-Leslie Brandt

Leslie Here. This is an excellent question and something many people in the climate change adaptation community are working to answer. Experts are doing vulnerability assessments to determine these impacts and find solutions to adapt. USAID, for example, is engaged on this subject. http://www.usaid.gov/climate/adaptation

Dr Don here from Smithsonian's National Zoo. Developing countries and many islands are found in the southern hemisphere, and have some of the highest levels of biodiversity on our small planet. We need this biodiversity of plants and animals for sustainable food sources, pharmaceutical medicines, and other reasons we don't even know yet. These countries have already suffered some species extinctions attributed to climate change, the golden frog and other amphibians in Costa Rica for instance. If we help mitigate climate change just so we can help save species that are necessary for functioning ecosystems or for our own human needs (medicines for instance).

Kurt here from USFWS. Entire island nations such as the Maldives and Kiribati are threatened by sea level rise. Low-lying countries such as Bangladesh are also threatened with drowning. Climate change is likely to have a profound impact on developing countries because they have less ability to adapt to the changes (because of less money, etc.). Climate change will affect agriculture, water resources, human health, transportation, etc.

In short, yes! There will be some species that may benefit from increases in temperature in some areas. Increases in carbon dioxide can also be beneficial to some plants. It serves as a fertilizer and can help them be more efficient with their water use.

-Leslie Brandt


Dr Don here. Climate change is caused by greenhouse gasses. You can reduce your contribution to the greenhouse effect by reducing, recycling and reusing a variety of products (including oil and electricity that is produced by coal-fired power plants). You can remember to turn off your TV and computer at the power bar, rather than at the machine. This actually cuts your use of "phantom power" (the draw on electricity when you think your TV or computer is turned off). If it's safe, walk or ride your bike to school or the store instead of going in a car. Buy local foods or grow your own! It's fun for the whole family and uses less power than buying everything from the store.

One simple thing you can do is to plant and care for trees! Trees take up carbon dioxide and can reduce your air conditioning use by creating shade.

-Leslie Brandt, U.S. Forest Service


Leslie Brandt here. Drought and food shortages are a huge concern and unfortunately there is no quick fix. However, we can do things to improve the quality of our soils by increasing organic matter content. This can help retain moisture during dry periods and reduce the risk of erosion.

Water managers, farmers and ranchers, and foresters pay close attention to climate outlooks to be aware if drought is coming. Though they can't make it rain, they can be prepared by invoking water restrictions, stocking up on hay for animals, and keeping campers out of areas where fires might start. Being prepared for drought can make the difference between experiencing a small loss and a much larger one.

Deke Arndt from NOAA's National Climatic Data Center here. There are multiple lines of evidence that help us know climate change is driven by human activity. First, we have physics and chemistry that date back several centuries. We've known about the heat-trapping properties of greenhouse gases for a long time, and the basic warming we see has been anticipated for decades. We still have much work to do to understand how the basic warming will be amplified by other processes, and exactly how it will influence certain types of weather, but we've had the basics down since before I was born (and I'm old).

Another way is just by looking at the data. We see lots of evidence that things are warming up down here at the bottom of the atmosphere, where we live. Temperatures are going up, glaciers are retreating, sea ice is shrinking over the long haul. All of these combined indicate that it's warming, but another key piece of evidence shows that it is driven by humans. That key piece is that the upper parts of our atmosphere are cooling. That tells us that the warming we're seeing is caused by changing the composition of the atmosphere, by increasing greenhouse gases.

Finally, when we take what we know from physics and chemistry (first paragraph) and what we know from observations (second paragraph) and combine them in models of our climate system, those climate models work really well to explain the big picture outcomes. The only way those models can re-create the warming we've observed is by including the greenhouse gas influence.

Simple physics. CO2 traps heat. Joseph Fourier discovered this principal back in 1824. It’s the same reason you put blankets on your bed when you are cold. It traps heat. You would never put blankets on your bed to cool down would you? I the same way, CO2 is like a blanket around the Earth. The more CO2 we add, the warmer it will become. Simple physics. http://en.wikipedia.org/wiki/Greenhouse_effect

To help answer this question, the U.S. Global Change Research Program's 2009 National Climate Assessment is great. http://nca2009.globalchange.gov/global-climate-change

"The Earth’s climate depends on the functioning of a natural “greenhouse effect.” This effect is the result of heat-trapping gases (also known as greenhouse gases) like water vapor, carbon dioxide, ozone, methane, and nitrous oxide, which absorb heat radiated from the Earth’s surface and lower atmosphere and then radiate much of the energy back toward the surface. Without this natural greenhouse effect, the average surface temperature of the Earth would be about 60°F colder. However, human activities have been releasing additional heat-trapping gases, intensifying the natural greenhouse effect, thereby changing the Earth’s climate.”

A large group of scientists (IPCC) in a recent report came to the conclusion that, “Human influence on the climate system is clear. This is evident from the increasing greenhouse gas concentrations in the atmosphere, positive radiation forcing, observed warming, and understanding of the climate system.”

More at: http://www.climatechange2013.org/

David Patte, U.S. Fish and Wildlife Service 

Avon Grove Charter School

REALLY hot. But, probably not because of man-made global warming. Lots of things could really warm the earth, such as a major increase in the sun’s energy output, or a change in orbit that would bring it closer to the sun, but the chances of this happening in your life time is about zero. Climate change will and is warming the Earth. Just how hot it becomes depends on if we want to do something to stop climate change. Without stopping climate change, the Earth will continue to warm for centuries to come.

Steve Mc. U.S. Forest Service


Deke Arndt from NOAA's National Climatic Data Center here. Yes, climate change will have an impact on our children. I have two at home myself. But I also know that our children will have an impact on climate change and we are going to be proud of what they accomplish. All of us, children and adults, can start work right now to help the next generation get a head start on dealing with the climate they inherit.

Hi, Talyn. This is Kurt Johnson of US Fish and Wildlife Service. I feel that climate change is already having an impact on our children, and will have an even greater impact on our grandchildren and even great grandchildren if we don't act quickly to curb greenhouse gas emissions. Climate change is/will affect children's health and well being because of changes in temperature and climate change effects on various diseases and air quality. Sea level rise and storm surges may displace many people including children, especially in the developing world. Changes in water availability and agriculture will also affect children, especially in the developing world. One reason I work on climate change issues is that I am concerned about my daughter and the world she will live in. I want her world to be as great as the one we are living in now.

Richie, that depends. How would the electricity be made? If through renewable resources like wind, solar, and hydroelectric power, then electric cars could reduce pollution. However, if we burn coal or oil to create the electricity, then electric cars may not have any impact on pollution.

Steve Mc. USDA U.S. Forest Service


They already have! Corn biofuel is already available and other forms are in development such as from grass and trees. The challenge is not in the development, but in the cost. If fossil fuels are cheaper, people will not buy biofuel energy. As prices for fossil fuels increase, then biofuels become more price competitive and you will see more of them.

Steve Mc. USDA U.S. Forest Service

Leslie Brandt here. Steve is right. Scientists are also working on developing biofuels from algae, but again the issue is making it price-competitive. Check this out: http://environment.umn.edu/momentum/issue/1.1f08/algae.html

LuAnn from NOAA responds:

Solar flares can send huge amounts of energy toward our planet. However, most of that energy gets reflected back into space by Earth’s magnetic field, so solar flares don’t have much effect on temperatures. The sun is the primary source of energy for Earth's climate system, so this is a good question, but it turns out that the energy from solar storms is different from the visible and infrared light that warm Earth’s surface.

You can read more about solar flares and climate here:

Dr Don from Smithsonian's National Zoo here. I garden a lot, and grow my own vegetables. In recent years (not this year!). I have been able to start my tomatoes earlier and earlier. Bees are out early, as the spring comes earlier, and pollinate my raspberries and peaches. In terms of non-beneficial wildlife, milder winters help rabbits and deer survive better, and they eat my garden! You may know that monarch butterflies are not doing well due to habitat change and reduction in milkweed that monarch caterpillars need to eat and grow. Warmer climate allows us to plant milkweed in new places, and hopefully we can help monarchs by doing this. One of the big winners is the group of invasive earthworms and insects that do so well in warmer climates, then eat my garden plants. So, there are winners and losers out there in the garden world during this climate change, just like there are animals and plants that are winners and losers in nature.

Hi, Deke Arndt here. One important factor in the Pacific NW, like everywhere, is water. The timing and the amount of summer stream flow is changing, and is expected to continue in the coming decades. This is because, generally speaking, the snowpack is melting earlier in the season than it used to and the summers have trended warmer and drier (and are expected to continue to do so).

It's always important to remember when talking about projected changes that we'll still have relatively hot, cold and dry and wet seasons. We're talking about averages here, but those are useful for planning.

I got my info on the Northwest from the National Climate Assessment's regional report: http://ncadac.globalchange.gov/download/NCAJan11-2013-publicreviewdraft-chap21-northwest.pdf

There's lots of good stuff in there if you want to dig in deep. Maybe a class project!

LuAnn from NOAA responds:

Decreasing snowpack and summer stream flows, increases in wildfires and insects, rising temperatures in streams where salmon spawn, and sea level rise are some of the climate impacts in the Pacific Northwest.

This website shows some of the climate impacts occurring in 9 different regions in the United States: http://nca2009.globalchange.gov/

Hi, I live in Portland and love hiking and visiting Washington. The latest scientific assessment shows that air temperature is rising pretty much on pace with the rest of the world. Precipitation is increasing slightly but patterns are difficult to discern. Other major changes include: Snowpack (in the mountains) is declining. Glaciers are thinning, retreating and fragmenting, and associated debris flows are increasing, affecting stream flow and water quality. Timing and amount of stream flow is changing, and stream temperatures are rising (Salmon and many other species need cold water). Wild fire risk and severity is increasing. Ocean chemistry is changing, and sea level is rising in the Puget sound and along the coast. Here’s a link to the scientific report: http://bit.ly/1kMuiTe

David Patte, U.S. Fish and Wildlife U.S. Forest Service

The draft National Climate Assessment is another resource:


Yes, there will very likely be another ice age. An ice age is defined as a period when there is ice on both the northern and southern poles. Currently, that is the case, so we are actually still in an ice age! The ice has been retreating for a long time but there is still a lot left compared to non-glacial periods. Between Ice Ages (there have been at least 5) the world looked really different from the way it does today. Antarctica, which now just has ice, snow and penguins, used to have dinosaurs and trees. However, over many thousands of years, the climate shifted and it became too cold for these plants and animals to survive and they could no longer live there. On the other hand, the area became a great place for penguins, so now they live in Antarctica instead of dinosaurs.

There will almost certainly be another ice age after this one. The sun is expected to last for another 10 billion years so there is a lot of time to have more changes to Earth’s climate.

From a question of how bad will an ice age be? It depends on who you are. If you are a dinosaur, an ice age is really bad news, but if you are penguin, really great news! Nature always has winners and losers. Right now, the climate is changing very rapidly due to human inputs of greenhouse gases. This makes is hard for people to adjust to the changing environment. That’s why scientists are so concerned. Change is always going to happen. It is the speed and degree of change that causes a problem.

Steve Mc. USDA U.S. Forest Service

That’s a question I’ve wondered about too, but it’s so far into the future. Here’s a NOAA science website that explains that the cooling sufficient to cause an ice age are not expected until about 50,000 - 100,000 years from now. http://www.ncdc.noaa.gov/paleo/milankovitch.html

Will climate change increase the earth’s temperatures to such a great amount that future cycles of cooling will not include an ice age? That’s hard to know given all the things that could happen in the next 50,000 years, such as whether we start to shift away from fossil fuels and greenhouse gases. To put it in perspective, our country founded in 1776 has been around for 238 years.

David Patte, U.S. Fish and Wildlife  Service U.S. Forest Service 

Dr Don here from Smithsonian's National Zoo. According to data in the report from the Intergovernmental Panel on Climate Change, and based on tidal gauge records for the last 110 years, average sea level rise around the world has been about 7.5 inches (.19 meters). Of course, sea level rise is different in different regions. I worked for some time in New York City, and I can tell you that the 7.5 inch average rise can be scary - a high tide during a hurricane or bad storm can now result in the ocean pouring over the seawall and into the city subway system (this actually happened during Superstorm Sandy in 2012). Of course this could wipe out shoreline communities of terrestrial plants and animals, and might create more habitats for near-shore organisms like crabs and oysters. This is the tradeoff we need to consider between winners and losers.

Here's a really cool NASA website with a sea level rise video and graphs: http://climate.nasa.gov/key_indicators#seaLevel

David Patte, U.S. Fish and Wildlife NOAA Fisheries Service 

I live in the southeastern US, so cannot speak directly to the changes in the Sierra Nevada Foothills, but generally, you can expect it to be warmer and the weather to be more variable. By that I mean, the rainfall will be more intense, and the summers will be hotter and longer. Those changes will likely become even greater over time.

Steve Mc. USDA Forest Service, Raleigh NC

Deke Arndt from NOAA's National Climatic Data Center here. Broadly speaking, the future climate will still resemble the current climate. You'll still have a "foothills" type climate. But you may notice some changes (and probably already have!) in the number of prolonged warm temperature spells and in snowpack patterns. You're in the middle of a pretty historic hot/dry episode right now.

One of the major concerns, really across the entire Western US, is how snowpack will be affected. This is important, because the snowpack is an important natural storage for water that is used later in the year for all kinds of purposes across the west. Some people even refer to it as a "frozen reservoir" on top of the mountains!

If the seasons warm, even if precipitation stays the same, less precipitation will fall as snow (more of it falling as rain). Combine this with the expectation that the seasonal snow melt will be earlier, and the water equation across the West becomes seriously different! This is an issue that a lot of folks are thinking about and working on, and there will still be plenty of work to do when you all move into college and the workforce!

In case you're wondering, there is some great region-by-region information in the latest National Climate Assessment, which is available in draft form (the final version is getting put together right now!) at: http://ncadac.globalchange.gov/

We’ve all heard that we should Reduce, Reuse, and Recycle: it’s all about using less energy to have the things we need.

Bringing your own bags for shopping is an example of Reuse—using an object over and over again to serve its original purpose. Reusing something instead of throwing it away keeps it from having to be manufactured again, which uses materials and energy (energy that is often produced by burning fossil fuels).

Some of us are used to seeing big bins for collecting paper and plastic for recycling. When we recycle, it takes energy to make these materials useful again, though not as much as it takes to manufacture them from scratch. However, if only one side of a piece of paper has been used, you can turn it over and reuse it. Similarly, you can refill plastic water bottles to reuse them. Recycling is a good thing when something cannot be used any longer, but reusing things in their current form requires less energy than recycling them.

Reducing means using less stuff in the first place, or decreasing the amount of waste we produce. One example of reducing is using drinking fountains, which reduce our use of plastic water bottles.

Reusing shopping bags is a good habit because it can reduce the amount of energy used to produce new ones. (posted by LuAnn Dahlman of NOAA)

Dr Don here from Smithsonian's National Zoo. We should use reusable or paper bags for shopping because they are friendlier for the environment. Plastic bags are made from plastics! First, most plastics are made from oil or other carbon-based compounds and we could be using that oil (or gas) in other ways if we weren’t using it to make plastic bags. Second, plastics take a long time to break down in the environment. Plastic bags are used for minutes, but have a life expectancy of about 1,000 years! And Americans use Billions of plastic bags every year! That is just a LOT of plastic trash. So, reduce your family’s use of plastic bags!

Where does a plastic bag really end up? Think about a plastic bag flying out of someone’s hand. It is carried by the wind across the lawn and into the woods. It might get ripped, but it keeps moving. It ends up in a stream, and if it doesn’t get caught on a fish as it moves downstream, it will eventually end up in the ocean. If the plastic bag remains whole, it will float out to sea and resemble a jellyfish. Sea turtles eat jellies, and do not recognize the difference between jellies and plastic bags. So, a sea turtle might eat the plastic bag and your plastic bag could help kill a sea turtle, or a dolphin or a whale.

What if the plastic just breaks down into small bits? The plastic bag could eventually break into small bits, even though the bits may take hundreds of years to decompose (plastic doesn’t decompose very well, unlike paper which is biodegradable). There are large areas in the oceans where wind and currents swirl around water in the middle that remains very still (these areas are called “gyres”). The plastic ends up here, and by this time it has broken apart into small bits. Scientists have found almost 2 million small bits per square mile in the “Great Pacific Garbage Patch” between Hawaii and California. Many small bits of plastic float at the surface of the gyres, cutting off light from phytoplankton. If algae and other plankton are killed, the entire ocean food web could be in danger! Scientists do not yet know the massive effect these large areas of floating plastic bits will have on the ocean environments.

Over 100 towns and cities across the US have banned plastic bags. Is your town one of them?

Ecosteve from the USDA Forest Service: Reusing bags saves trees and energy.

It's important to distinguish climate from weather. Climate is the long-term average temperature and precipitation conditions in a particular place, while weather is what you experience from day to day. A number of factors contribute to your local weather conditions, such as the jet stream, ocean circulation patterns, and local topography. This is a very complex system, which is why it's sometime difficult even for experts to forecast exactly what is going to happen regarding the weather in a particular place.

-Leslie Brandt

Hello to both of you! Deke Arndt here. Even without considering climate change, winter is a season of quick and dramatic change in our part of the world. You live in the middle latitudes, between the persistent warmth of the tropics and the constant cold at the poles. In winter, abrupt changes are part of the deal here, usually when that cold air invades from the north. I'm in NC, up in the Appalachians where that situation is going to happen today! We've been warm for the past few days, and that's about to change!


Dr Don here from Smithsonian's National Zoo. Animals are already moving from temperate zones toward the poles, and the poles are warming faster than anywhere else on Earth. Several years ago we observed cowbirds from our Tundra buggy platform in Churchill Manitoba! These birds should not be that far north, and this sighting was later confirmed by ornithologists. Other birds have moved toward the poles. Mosquitoes are moving toward the poles, and up mountainsides, carrying mosquito-borne diseases into places it has never been in human history. Orcas have entered the Hudson Bay, and have killed beluga (white) whales near Churchill - this provides food for hungry polar bears, but isn't good for the belugas! Finally, the golden toad of Costa Rica is one of the first climate-change caused extinctions, and there are other amphibians that have apparently gone extinct due to climate change (for instance, gastric brooding frogs from Australia).

Ecologists are wondering the same thing as you are! One set of scientists approached the question by figuring out how fast climate zones are moving toward the north and south poles. They calculated that plants and animals would have to move about one-quarter mile per year (almost 4 feet per day!) to continue experiencing the same climate.

Robert Krulwich of National Public Radio recently posted a good description of their research (complete with cartoon drawings and links to the research papers) here: http://www.npr.org/blogs/krulwich/2014/02/18/279189378/trees-on-the-move-as-temperature-zones-shift-3-8-feet-a-day

Leslie Brandt here from the Forest Service. In my job, we are focusing on how climate change will affect our trees and ecosystems. As a general rule, individual trees at the southern end of their range are the ones we expect to be hardest hit. We also expect species that currently live at high elevations will be vulnerable because they cannot migrate easily to colder locations. On the flip side, some species are adapted to a wide range of climates and may do well.

That a great question. Good examples by Dr Don and the other post. This gets pretty complicated and interesting once you consider all the possibilities. Climate change can change biodiversity at the individual, population, species, ecosystem and even biome levels. In a technical sense, four key areas have been researched: 1) physiological effects (how will the normal functions of a plant or animal be effected?); 2) phenological effects (how will a plant or animal’s seasonal cycles be effected?); 3) distributional shifts (how will a plant or animal change locations where it can thrive?); and 4) interspecific interactions (how will plants and animals change when other plants and animals around them change?). A key climate change concept is that individual plants and animals will respond to climate variation independently, uniquely, and on differing time scales.

So, all together this will create a species behaving differently, some doing well, others suffering unless they can move around. And we’re seeing new mixes of species. How it all works out is a real unknown, and a change in one population, species, or a whole family of species can trigger complex “cascading” effects to others.

David Patte, U.S. Fish and Wildlife Service

Sea turtles such as the green sea turtles at Midway Atoll National Wildlife Refuge in the picture will be affected by sea level rise and also rising temperatures. They lay their eggs on the beach so rising waters and storms will make these areas vulnerable. Also, the eggs are buried into the sand for protection and also so they don't get too hot. It turns out that with sea turtles, temperatures determine the sex of the offspring. In other words, the hotter it gets, the more females are born. That can be fine to a certain point, but obviously we need both, right?

David Patte, US Fish and Wildlife Service

Leslie Brandt here. Scientists don’t really know exactly how long it would take to melt all the ice caps, but some think it could take 5,000 years or more for Antarctica to completely melt. Ice in the arctic and Greenland would melt much sooner, however. To see what the world would look like if all the ice melted, check this out: http://ngm.nationalgeographic.com/2013/09/rising-seas/if-ice-melted-map


Deke Arndt here. This is a pretty complex question, because "ideal" really depends on a lot of factors. Even within agriculture, ideal for citrus crops isn't the same as grains. But I'll give it a shot. It's important to remember that, in a warming world, the "ideal climate" will be (and already is) a moving target. That means it may migrate past a spot, but will not likely stop there. It may move on, even within a generation as things speed up more.

With that said, as a general rule of thumb (helpful most of the time, but not true everywhere), the overall long-term temperature patterns will migrate poleward (in America, southern temperatures will push northward over time).

Hi Penny. This is Kurt Johnson from Fish and Wildlife Service. Yes, there have been a number of studies that address the issue of how conditions will change for people, agriculture, water resources, wildlife, fisheries, etc. depending upon how much the climate actually changes. These studies usually use computer simulations to give an idea of how conditions will change based upon a certain amount of warming and/or precipitation changes. So these are only projections, because no one knows for sure how much change there will be. I will try to find a reference or two for you.

Kurt again. Here is a Wikipedia article about climate change and agriculture, as an example. I hope you find it interesting and useful! http://en.wikipedia.org/wiki/Climate_change_and_agriculture

I try to make our home as energy-efficient as possible. Simple things like switching to all compact fluorescent and LED bulbs, turning off lights and electronics we are not using, using a programmable thermostat, insulating our house, and trying to minimize the use of air conditioning all can help.

We are also doing a lot in our backyard! We have put a lot of effort into planting and caring for trees, which take up carbon dioxide. Their shade can also help keep your house cool and trees can help take up storm water as well. We also grow our own vegetables in the summer, which is good for a number of reasons, including reducing greenhouse gas emissions! We also have a compost bin in our backyard where we put our food scraps and yard waste, which keeps things out of landfills and helps out our garden.

-Leslie Brandt

Deke Arndt here. Like most of the folks that answer this question, the steps I take are geared toward reducing energy use: local food, walking instead of driving (when I can), combining trips and so on. I also travel a lot less for business than I used to. Another way to help is fixing things, instead of replacing them. It does take time, but saves lots of energy (and money too!). Most of these steps are common-sense approaches that also pay off for your health and even your pocketbook. These individual approaches do help, but working with neighbors and communities on mutual solutions goes even farther!

Leslie Brandt again: Our neighborhood has a used item barter/sell group (sort of like craigslist but within walking distance of my house). I buy used items from my neighbors which helps keep things out of landfills, builds communities, reduces my travel distance for shopping, and saves money!

Dr Don here from Smithsonian's National Zoo. I take public transportation whenever I can to save on gas. I eat foods that are grown locally and that are in season as much as possible, because it has a smaller “carbon footprint” (it has moved from shorter distances). I grow a lot of my own produce. Even if you live in an apartment building you can grow tomatoes in a planter!

I also visit my local accredited zoo or aquarium, or nature center, to see what they are doing about climate change and saving species locally. Often they have good tips about how we can help keep our environment healthy.

LuAnn's answer: I always combine my errands to reduce the number of miles I drive, and I choose local products and services whenever I can. Also, I recently needed to replace my refrigerator. :( I shopped carefully and chose one of the most efficient models I could find. This is important because I expect it to continue working for ten or more years. The energy savings will continue to add up over its entire lifetime.

You can find out how efficient many household appliances are by visiting the Energy Star Website: http://www.energystar.gov/

Leslie Brandt here, from the U.S. Forest Service. A few months ago, President Obama released a new executive order on preparing the United States for climate change. This focuses on federal agencies coming together with other partners to prepare for the risks of climate change. You can read more about it here: http://www.whitehouse.gov/the-press-office/2013/11/01/fact-sheet-executive-order-climate-preparedness

The Forest Service is part of the US Department of Agriculture (USDA). The USDA has just developed a set of regional climate hubs to help farmers, ranchers, and forest managers adapt to climate change and weather variability. You can learn more about them here: http://www.usda.gov/oce/climate_change/regional_hubs.htm

Deke Arndt here. Following up on Leslie's post. A lot of efforts are focused on adapting to the changes we already see and those we know are coming. Those of us responsible for carrying out the work of the administration (any administration, not just this one) know that we're going to have to do a better job of working with each other and with communities to understand and use and share the tools that are already available. The "drought community" (yes, there is one) already does a great job at this (http://www.drought.gov). I really admire the way they've been ahead of the curve. Many of the agencies are working on getting their region-by-region climate folks to mesh together as smoothly as the drought folks have done!

Leslie again. Deke is right. We are doing a lot already. I'm part of the group called the Northern Institute of Applied Climate Science. We work across organizations to help our forests adapt to a changing climate. You can learn more about our work here: www.forestadaptation.org

Hi Bre! This is Kurt Johnson from US Fish and Wildlife Service. You've asked a tough question, and one with no easy answer. Climate change is already affecting large segments of our society. Future impacts to society and the economy will depend on how much the climate changes and how much that change influences things like sea-level rise, wildfires, pest species, invasive species, and water resources. It also depends on how these changes interact with other stressors such as habitat loss and pollution.

Every few years the U.S. government prepares an assessment of the nation's climate. A new National Climate Assessment is nearly complete. The report talks a lot about the potential impact of climate change to various parts of the US economy. Here are some pertinent quotes from the Executive Summary: "Climate change is already affecting human health, infrastructure, water resources, agriculture, energy, the natural environment, and other factors – locally, nationally, and internationally. Climate change interacts with other environmental and societal factors in a variety of ways that either moderate or exacerbate the ultimate impacts. The types and magnitudes of these effects vary across the nation and through time. Several populations – including children, the elderly, the sick, the poor, tribes and other indigenous people – are especially vulnerable to one or more aspects of climate change. There is mounting evidence that the costs to the nation are already high and will increase very substantially in the future, unless global emissions of heat-trapping gases are strongly reduced." "Climate change threatens human health and well-being in many ways, including impacts from increased extreme weather events, wildfire, decreased air quality, diseases transmitted by insects, food, and water, and threats to mental health. Climate change is increasing the risks of heat stress, respiratory stress from poor air quality, and the spread of waterborne diseases. Food security is emerging as an issue of concern, both within the U.S. and across the globe, and is affected by climate change. Large-scale changes in the environment due to climate change and extreme weather events are also increasing the risk of the emergence or reemergence of unfamiliar health threats.”

The draft National Climate Assessment is available at: http://ncadac.globalchange.gov/

Changing peoples’ attitudes is hard if they do not believe change needs to happen. Even with lots of scientific data, many people still think the current climate change is part of a natural cycle (but many scientists say the climate is changing faster, and in the opposite historical direction, of the natural cycle). Maybe as they notice the big changes in their local area – the drought out West, the bigger hurricanes, unusual snowfall or rainfall in their area – they will see for themselves that the weather is becoming more extreme. If they experience this extreme weather more often, they will link it to climate change eventually and then hopefully their attitudes will change, so they take their own personal climate actions.

Thanks for your great question,
Dr. Don Moore
Senior Scientist for conservation programs, Smithsonian's National Zoo

Leslie Brandt here. As it pertains to climate change, a good first step is to provide people with credible information in a way they can understand it and not feel overwhelmed. Events like Climate Change Live are great in that regard. It also helps if people feel like they have the ability to do something about it. When I work with foresters, they often feel a lot more comfortable about confronting climate change if they realize they can make small changes that will help prepare their forests for climate change using tools they already have at their disposal.

Not during our lifetimes! Now, that may sound bleak, but bear with me for a while. First of all, the scientific reason behind this is that additional carbon dioxide, the dominant greenhouse gas, lasts several centuries - up to about 1,000 years - in the climate system. That means that we've committed to artificial warming for centuries. This may sound defeating, but we can still control whether we add even more to that. We still have control over our long-term outcomes. Just because we've already committed to some artificial warming doesn't mean we have to commit to even more. We still control our destiny, both by adapting to the warming we've already committed, and by working to reduce and eventually eliminate any additional warming commitment. Your generation is going to play a huge role in how things play out!

Thanks for your question!
Derek Arndt
Chief of the Climate Monitoring Branch
NOAA National Climate

Hi Patty. This is Kurt Johnson from Fish and Wildlife Service. I will try to post a few links here that might give you some of the information you are looking for. Here is a web page that NOAA maintains that shows sea level trends around the world: http://tidesandcurrents.noaa.gov/sltrends/sltrends.shtml

You can see that sea level is actually dropping in many places in SE Alaska.

Hi! Kurt Johnson again! Areas of southeastern Alaska reflect a decrease in relative sea level because the region is dominated by isostatic rebound, or regional uplift of the land caused by the retreat of the glaciers. I will try to find a good, non-technical reference on this.

Hi! This is Leslie Brandt. Here is an article from the New York Times that talks about this trend:


It's Kurt again. Here's a slightly older paper that talks about uplift in SE Alaska:



 Kennedy, do you like money?  Fruits, vegetables, cows, chicken and pigs (to name a few) will be more expensive to produce with climate change so they will cost more.  It will also cost more to cool your house, and health care costs will increase, and that will cost you (or your parents) money, meaning that there will be less for you.  Do you like to see wild animals?  Many animal species will be harmed by climate change so there will fewer to see.  Do you like to swim in lakes?  Climate change will cause more droughts so some lake may dry up as water demand increases and water availability decreases.  If you care about any of these things, then you should care about climate change impacts.

Steven McNulty, Ph.D.


USDA South East Regional Climate Hub (SERCH)


Most people are pretty happy about living, and most people are not going to die because of climate change (today or in the near future).  However, people in the poorest countries such as those living in the continent of Africa often live under very hard conditions. Under the of best circumstances, there may be little food, clothing or shelter. Anything the makes these conditions worse, like climate change can mean the difference between life and death.  Even in the US, 1 out of 5 children to not have enough good food to eat.  If climate change makes living more expensive, their situation will only become worse.  Climate change or not, no child should go hungry, and they do care, very, very, much.

Steven McNulty, Ph.D.


USDA South East Regional Climate Hub (SERCH)


Christopher, the good news is that as a race, humans are the most adaptable animals on the planet.  We live in deserts, high mountains, artic cold, tropical rain forests, and everywhere in between.  So no matter how bad climate change becomes, the human race will not likely go extinct.  HOWEVER, climate change will (and does now) cause individuals to die.  Whether by insects such as malaria,  starvation due to crop failure, heat related illness, or civil unrest (war), climate change is and will be responsible for many deaths around the world, and unless we act,  millions (maybe 100’s of millions or more) will die due to climate change impacts in the decades to come.


Steven McNulty, Ph.D.


USDA South East Regional Climate Hub (SERCH)


 Hi Hope,

The effects of climate change are very serious. A group of hundreds of scientists from around the world called the Intergovernmental Panel on Climate Change just recently released a big report on the impacts of climate change across the globe. The report says that impacts of climate change have already affected farming, people’s health, ecosystems on land and in the oceans, water supplies, and some people’s ways of making a living. Impacts of climate change are being experienced in countries large and small, rich and poor, and from all parts of the globe.

Although we are already experiencing effects, the scientists in the report warn of additional risks if temperatures rise even a little bit more. With just a few degrees Celsius rise in temperature compared to current levels, there is a high risk of dramatic losses in biodiversity, sea level rise, more extreme storms and heat waves, and widespread crop losses. Exactly how quickly temperatures will rise depends on how quickly and by how much greenhouse gases rise in the atmosphere. However, given our current trends in emissions, it’s likely that temperatures will rise an additional 2 degrees Celsius or more by the end of this century, enough that many of these risks could be experienced within your lifetime. 

Leslie Brandt,

Climate Change Specialist,

U.S. Forest Service and

Northern Institute of Applied Climate Science

 Hi Kendeli,

The effects of climate change are already being experienced across many diverse parts of the world, including droughts, sea level rise, and more extreme storms. If we don’t start making changes to reduce our greenhouse gas emissions, these effects could become much worse and we could see dramatic effects on plants and animals and the people who depend on them. A group of hundreds of scientists from around the world called the Intergovernmental Panel on Climate Change has explored the consequences if we don’t take steps to reduce our greenhouse gas emissions. If we continue to emit greenhouse gas emissions at the rate we are currently, it’s likely that temperatures could rise an additional 2 degrees Celsius by the end of the century, which puts us at a high risk for these impacts.

Leslie Brandt,

Climate Change Specialist,

U.S. Forest Service and

Northern Institute of Applied Climate Science

No model is needed to see why oxygen has not changed despite changes in CO2. Looking at the math will help to show the answer. By weight, CO2 comprises about 0.05% of the atmosphere (it keeps going up because we keep adding more CO2 with fossil fuel burning). Before the industrial revolution around 1770, CO2 was about 0.03% and now it is 0.05%. This is a difference of 0.02%. Because CO2 is a greenhouse gas, that little change has a big impact on Earth temperatures. However, when compared to a big percent like oxygen (or nitrogen) the 0.02% is a drop in the bucket. So even though CO2 has increased by 70% (0.03/0.05), oxygen has not changed hardly at all (1 - 21/20.98) = 0.001% change in oxygen.


Steven McNulty, Ph.D.

Director USDA South East Regional Climate Hub (SERCH)

920 Main Campus Dr., Suite 300 Raleigh, NC 27606






Carbon monoxide (chemical formula CO) is a gas poisonous to humans and other animals so the option for cars would be to not produce the gas at all! There are many experiments that are attempting to reduce CO emissions through increased fuel efficiency or by converting gasoline driven vehicles to electric. If electric cars are recharged using solar, wind or hydroelectric power generation, the amount of CO emitted into the atmosphere is greatly reduced. So there are also experiments to make these forms of electricity generation more cost effective.


Steven McNulty, Ph.D.

Director USDA South East Regional Climate Hub (SERCH)

920 Main Campus Dr., Suite 300 Raleigh, NC 27606




Hello Harriet!

Great question! There are many ways for you to help. Please take a look at our activities here:


You can even pass information on to your teacher to share with your classmates:



Tabitha C. Morgan

Policy Analyst

Research and Development

USDA Forest Service

Hi Zach. The definition of climate change is a change in the climate. Since rising temperature is a change in the climate, then rising temperatures do not cause climate change, but ARE climate change. Also, rising temperatures can cause the white Arctic ice to melt and expose more dark ocean. The dark ocean absorbs more solar radiation than does the ice so in turn that causes more warming. Rising temperatures can also cause more decomposition of soil organic matter and melt permafrost which releases another global warming gas called methane. Both of these processes also cause climate change.  So your Dad is right. Rising temperatures does cause climate change.


Steven McNulty, PhD

Director, USDA South East Regional Climate Hub (SERCH)

U.S. Forest Service


Jerry, global CO2 concentrations are now over 400 ppm, and could more than double by the end of this century. There really was not crisis during the Triassic because there were no people (but lots of dinosaurs!). We are a LONG way from 2300 ppm, but we do not need to be at those levels to have problems. Even at the current levels, and Arctic is melting and the seas are expanding as they warm. These two factors are causing sea level rise which could flood cities like New York, Boston, Miami and many others around the world. Additionally, the current levels of CO2 are increasing the amount of flooding, soil erosion and other important ecosystem processes. Just think of how many more problems there will be if the CO2 rises even a little bit, let alone doubles to 800 ppm.


Steven McNulty, PhD

Director, USDA South East Regional Climate Hub (SERCH)

U.S. Forest Service

Zarwa, most of human caused part of climate change is caused by the release of carbon dioxide into the atmosphere. The more carbon dioxide released, the more global warming. Since most people live in cities, that is were a lot of the carbon dioxide comes from that causes global warming. However, if people cut down forests and do not replant trees then that can also cause climate change. Most tree cutting occurs outside the city. 


Steven McNulty, PhD

Director, USDA South East Regional Climate Hub (SERCH)

U.S. Forest Service

Climate change is fixable. The cost will depend on how long we wait to fix it. Climate change is like a car. You need to change the oil in the car every 3,000 miles so that the car runs well. Changing the oil is cheap, but if you wait, your engine can be damaged, and that is expensive to fix. If we fix climate change now by using less fossil fuels, then we will not need to do expensive fixes like building walls to keep rising seas from flooding our cities, or having increasingly variable climate ruin our crops.

Steven McNulty, PhD

U.S. Forest Service,

Director of USDA South East Regional Climate Hub (SERCH)

Emma, have you ever tried to paint water? Since the dark oceans are what absorb more heat, we would need to paint the water. I don’t think that would work very well! In Switzerland they are trying to keep the glaciers from melting so fast. They are experimenting with putting HUGE reflecting blankets on them. It is VERY expensive, and not all that successful. It is much easier to slow down climate change than it is to fix all the problems climate change is causing.


Steven McNulty, PhD

Director, USDA South East Regional Climate Hub (SERCH)

U.S. Forest Service

Detroit Climate Youth Summit from Michigan

Good question!  Paper is made out of carbon that has been removed from the atmosphere.  So if the paper is not allowed to decompose, then paper use could reduce atmospheric CO2 and help reduce climate change.  However, fossil fuels are required to harvest the trees, turn the wood to paper, and transport the paper to you.  Unfortunately, the fossil fuel use of making and delivering paper out-weight the value of sequestering carbon in the paper, so next time save paper, or at least print on both sides. (From Steve McNulty, Director, USDA Southeast Climate Hub, US Forest Service) 

Grass is better for your football field for several reasons.  (Artificial) turf is made from fossil fuels and the drilling, removal, processing, transportation and installation all require fossil fuel use. In contrast, grass will use much less fossil fuel. (From Steve McNulty, Director, USDA Southeast Climate Hub, US Forest Service) 

Reports from the Intergovernmental Panel on Climate Change (IPCC) are good sources for an unbiased evaluation of the best available science on climate change and its impacts across the globe. Thousands of scientists from all over the world contribute to the work of the IPCC on a voluntary basis. All IPCC reports are extensively reviewed by scientists to ensure an objective and complete assessment of current information. For climate change impacts on the United States specifically, an excellent source of information is the National Climate Assessment (NCA). For the NCA, a team of more than 300 experts guided by a 60-member Federal Advisory Committee produced the report, which was extensively reviewed by the public and experts, including federal agencies and a panel of the National Academy of Sciences. Both the IPCC and NCA reports are excellent resources because they summarize key findings from scientific research in ways the public can understand. Everything is backed up by peer-reviewed literature, so you can always go look up the supporting papers on a topic if you want to learn more.  (From Leslie Brandt, Climate Change Specialist with the US Forest Service) 

Detroit Climate Youth Summi tin Michigan
Changes in climate can affect diseases in trees in a few ways. As winters warm, insect pests that carry diseases, or the diseases themselves, may be able to survive in places where they may not have been able to before. Wetter conditions, as are projected for a lot of the Midwest and Northeast in the spring, could be favorable to certain types of fungal pathogens. There may also be indirect effects of climate change on diseases in trees: as trees become stressed from heat, drought, or flooding, they can become more susceptible to diseases.
Climate change can also affect human health in many ways. Warmer temperatures in the summer can lead to higher ozone levels and other pollutants in the troposphere, which can be especially harmful for people with asthma, the elderly, and those with compromised immune systems. Warmer temperatures and increased carbon dioxide can also increase the amount of pollen in the air, and lead to longer, more intense seasonal allergies. Milder winters could potentially lead to an increase in the amount of vector-borne illnesses such as Lyme disease. Large flooding events can compromise water quality and lead to waterborne illnesses, especially in developing countries.  (From Leslie Brandt, Climate Change Specialist with the US Forest Service)    

The terms may often be used interchangeably in every day conversation. Yet “global warming” is actually a narrow part of the broader topic of climate change.  Global warming refers to the long-term, observed trend of rising temperatures at the earth’s surface, as recorded and then averaged for the whole planet.  Indeed, that global average shows an increase of 0.74oC or 1.3oF over the last century.

This global average trend does not fully represent the nature of changes scientists expect to occur in any particular region, though.  We do not observe a simple, steady warming trend in every location on the earth’s surface, as we do when we average all those observations for the whole planet.  In any particular place, for example, we may actually observe “colder colds” and “hotter hots” over the course of the year, or an increasing frequency of extreme weather events.  These dynamics are explained by a number of interacting factors—like the complexity of the global climate system, the varied topography of the earth’s surface, and ocean-landmass interactions.

So in summary, compared with the narrower term of global warming, climate change encompasses a broader suite of changes like increased climate variability; changes in the timing, form and pattern of precipitation; sea level rise; and other dynamics important for society to understand.


Amy E. Daniels, PhD
National Program Leader for Landscape Science
U.S. Forest Service




This is a very good question and a lot has been written about whether the increase starting around 8000 years ago might have been due to early human activities.  The suggestion that this might be true was made popular by Bill Ruddiman, emeritus professor at University of Virginia, and he has written several articles and a book about the idea (http://www.evsc.virginia.edu/ruddiman-william-f/).  Other scientists don’t believe it was possible that there were enough humans on earth to cause the increasing trend, and instead point to ocean sources of carbon increasing over this time period.  See a paper by Elsig et al. (Nature, 2009) for that information.  (From Ed Brook, Oregon State University, College of Earth, Ocean and Atmospheric Sciences)

Scientists are still uncertain about what the future trends in tornadoes will be[1]. It’s difficult to tell exactly how tornado-inducing processes may change in the future, because tornadoes happen at much smaller scales than the large computer models scientists use to understand future changes in climate. Tornadoes are a result of both moist, warm air rising into the atmosphere (which can also lead to thunderstorms) and another process called wind shear[2]. In general, current climate models suggest that we will have more thunderstorm-inducing warm air, while wind shear may decrease[3]. This could potentially mean more thunderstorms, but it’s unclear if conditions may also lead to more tornadoes[4]. Scientists do think that the tornado season may shift to different parts of the year, and more tornadoes may occur in clusters, but more research is needed before we know for sure.

Leslie Brandt, Climate Change Specialist, U.S. Forest Service, Northern Institute of Applied Climate Science 
http://climatefamework.org/contact (Tornado in Union City, Oklahoma on May 24, 1973. Image Credit: NOAA Photo Library, NOAA Central Library; OAR/ERL/National Severe Storms Laboratory (NSSL)

Many seasonal allergies are caused by pollen. Climate change is affecting when plants produce pollen and how likely that pollen is to cause an allergic reaction. In the spring, tree pollen is the major cause of hay fever allergies. Spring is arriving 10-14 days earlier across much of the United States, meaning that some trees are starting to produce pollen earlier.  Because other trees are still pollinating at the same time they always have, the overall pollen season is getting longer. It is also likely that climate change will make it possible for more allergenic trees—like oak and hickory—to expand into new areas, replacing less allergenic species.

Late summer and fall allergies are typically due to ragweed, a hardy plant that is found across the country. The increasing carbon dioxide in the atmosphere has acted like a fertilizer to these plants, which are growing faster and producing more pollen. The extra carbon dioxide may also be increasing the amount of the protein in the pollen which causes allergies, making the pollen itself more allergenic. And, finally, a longer growing season means that the plants can get bigger and produce even more pollen.


Amanda Staudt
Senior Climate Scientist
For more info:



Dear Zaire,

There are a number of ways to reduce the emissions of carbon dioxide and other greenhouse gases: this could involve burning the same fuel to produce the same amount of energy with less greenhouse gas emissions, changing to a different fuel that produces the same amount of energy with less greenhouse gas emissions, or reducing the amount of energy consumed leading to burning less fuel (and therefore less emissions).

Examples of ways to use the same fuel while producing less emissions are capturing the carbon dioxide after it is burned and storing it underground (carbon capture and sequestration), or improving the efficiency of the power plant or engine. Additionally, it is possible to use the waste heat from a power plant to heat nearby buildings, a process called cogeneration, which also increases efficiency.

Changing fuels to get the same amount of power with less emissions would happen when moving from a fuel with more carbon to a fuel with a higher carbon content to a fuel with a lower carbon content (or no carbon emissions at all). Usually, switching from coal to natural gas, or from natural gas to nuclear power or renewables like solar or wind power, will allow for producing power with less emissions.

Finally, in addition to using the same fuel more efficiently, or using different fuels with lower emissions, there is also the option of reducing our usage of energy overall, which would require less fuel to be burnt. Reducing energy usage itself can be broken down into multiple categories: improving efficiency (like using LED lights rather than incandescent lights), using less (turning off lights when leaving a room), or reducing the loss of energy when moving it from one place to another over power lines.

I hope this answers your question,


-Marcus Sarofim, PhD

Environmental Scientist

Environment Protection Agency, Climate Change Division


Editor's Note:  Here's a link from the Environmental Protection Agency that describes alternative energy sources and how they work:  www.epa.gov/climatechange/kids/solutions/technologies

Jennifer from Texas


To Jennifer, a 5th Grade student in Texas:

The short answer is “yes.” Colorado has already gotten warmer and will continue to do so.

The world’s leading climate scientists agree that the planet is getting warmer.[1] In Colorado, average air temperature has increased by about 2oF over the last 30 years.[2]  Looking forward, scientists estimate that Colorado will warm around 4oF by the middle of the century compared to the average temperature from 1950 to 1999.[2]   

These warmer temperatures will also affect the timing and amount of water available.  As the climate warms, winter snow melts and drains off the landscape earlier.  Also, more water evaporates and is held in the air instead of being available in our rivers, for watering food crops, or for drinking water.  These impacts on water resources will be very big deal for Colorado in the coming decades because the state already has a low water supply.[3]

I see that you’re from Texas.  So in terms of whether you may personally experience or perceive climate change when, for example, visiting Colorado for a winter ski trip...

Well, remember, climate is the average weather for a location over 30 or more years.  So even though Colorado is getting warmer, that doesn’t mean we won’t have some very cold days, snowy winters, or just cold weather more generally.  Colorado’s landscapes vary from the flat plains to high mountain peaks reaching over 14,000 feet high.  Since increasing elevation generally makes for a colder climate, temperatures and their long-term trends can vary even over short distances in Colorado.  The weather you experience during any particular visit to Colorado may not be attributed to climate change.  But if you make a similar trip every year for most of your life (same place, same season, etc.), you may begin to notice changes over time.

Amy E. Daniels, Ph.D.

National Program Leader for Landscape Science

USDA Forest Service, Research & Development





 To Middle School Teacher, Joshua -

These two questions highlight the need to distinguish the concept of weather (what you experience at a given time point) versus climate (which is a long-term average of weather over 30 years or more). There will always be variation from year to year even if there is a long-term trend.

Arctic sea ice extent in 2012 was the lowest on satellite record, and much lower than the long-term trend[1]. Summer mean temperature in the Northern Hemisphere in 2013 was much cooler than 2012, so another record year was not expected. Even so, according to NASA[2], ice extent in 2013 was still the sixth lowest on record and lower than the 1981-2010 average. The 2013 ice extent is generally in-line with downward trends in minimum ice extent for the Arctic, which has been decreasing about 12 percent per year on average.

A number of climate skeptics have argued that temperature increases appear to plateau over the past 15 years. The Intergovernmental Panel on Climate Change, which provides scientific consensus reports on climate change to the United Nations, has just released a new report[3]. In it, the authors acknowledge that trends from 1998 to 2012 are much less pronounced than the long-term trend from 1951 to present. The authors of the report argue that this so-called plateau may be driven by a variety of factors, including the redistribution of heat in the ocean and variation in the solar cycle. In addition, a lot of the apparent reduction in warming is from selecting 1998 as a starting year in the analysis, which was one of the hottest years on record. If long-term trends are instead calculated from 1996 or 1997, the 15-year trend lines up with the long-term trend of an increase of about 0.12 °C per decade.  It’s also important to note that many of the hottest years on record have occurred in the past 15 years, and the decade from 2001-2010 was the warmest on record according to the World Meteorological Organization[4].

Leslie Brandt,

Climate Change Specialist,

U.S. Forest Service and

Northern Institute of Applied Climate Science






ananda from north carolina

One way we know the earth has warmed is the rapid decrease of ice in recent years in the northern Arctic, southern Antarctic and mid-latitude glaciers. We have photographic evidence from our space satellites that show this decrease in ice cover, and ground-level photographic evidence from our own Glacier National Park (see Grinnell glacier’s change from 1940 to 2006 at http://nrmsc.usgs.gov/repeatphoto/). Another way we know the earth is warming is from movements of species from more temperate areas to regions that were previously cold; these species include dozens of bird species documented by decades of Christmas Bird Counts, insects documented by scientists, and even plants. Scientists continue to document these changes so that we can figure out ways to adapt best to our changing world.

Dr Don

Donald E Moore III, PhD

Associate Director for Animal Care Sciences

Smithsonian's National Zoo

Smithsonian Conservation Biology Institute

Office of the Director, MRC 5508

Editor’s note:  Weather records, tree rings, fossils, ice cores, pollen, and others, also give us a record of earth’s climate and warming.  You can check our website link, “What We Know About Climate Change” for more info.


Nerddett, 5th grader from New Mexico

 Will it ever snow a lot in NM?

Some areas in New Mexico do observe good snowfall! If you live in the southern half (Deming,Las Cruces, Alamogordo), you won't get as much snow compared to the northern areas, especially the mountains (Angel Fire, Taos, Red River).

Every now and then, a big snow storm will hit much of New Mexico, like the one that brought nearly 2 feet of snow to Albuquerque back in 2005-2006, but for the most part, New Mexico as a whole won't see as much snow compared to the northern states.

Broadcast Meteorologist,  Jorge Torres at KOB-TV in Albuquerque, NM:


Wanda, 5th grader from New Mexico

 Wanda -

The atmosphere on Earth is in a state of constant motion. Because the Earth is round and not flat, the Sun's rays don't fall evenly on the land and oceans. The Sun shines more directly near the equator bringing these areas more warmth. However, the polar regions are at such an angle to the Sun that they get little or no sunlight during the winter, causing colder temperatures. These differences in temperature create a restless movement of air and water in great swirling currents to distribute heat energy from the Sun across the planet. When air in one region is warmer than the surrounding air, it becomes less dense and begins to rise, drawing more air in underneath. Elsewhere, cooler denser air sinks, pushing air outward to flow along the surface and complete the cycle. Because of this, the atmosphere contains different air masses, temperatures, and moisture. With the air masses moving at different speeds and levels it causes the changes in weather.

Meteorologist, Crystal Wicker, Weather Wiz Kids


 To 5th grader from Alaska

Here’s a good link that describes how solar panels work.  This Highlights website has answers for lots of other kids’ science questions, too!    Good luck on your project, and check out these kids and the solar cars they built!


Also found this link from the Environmental Protection Agency on alternative energy technologies and how they work.  Here's the solar panels piece:  www.epa.gov/climatechange/kids/solutions/technologies/solar.html


Vicki Arthur

U.S. Forest Service

Conservation Education Specialist



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