Essential Questions

The Climate Change: The Threat to Life and A New Energy Future exhibition explores how climate works, why it is warming, what the consequences might be, and how to address them. Use the Essential Questions below to connect the exhibition's themes to your curriculum.

What is climate?
Climate is the long-term state of weather: the typical weather in a particular region over years. The Sun drives climate by warming the air, land, and sea. The oceans and atmosphere transport this heat from the tropics to the poles. In the short run, this transfer of energy creates weather (like a tornado or a sunny day); over the long run it creates climate (warm near the Equator, for example, or cold near the poles). The distribution of landmasses, the amount of ice cover, and the presence of life also play important roles in Earth's climate system.

How does climate change?
In the past, temperatures at Earth's surface have risen and fallen naturally. Glacial periods alternated with shorter, warmer interglacial periods like the one we're in right now. However, temperatures remained within a range that has enabled life to survive and evolve for more than 3 billion years. That's because gases in the atmosphere, known as greenhouse gases, absorb heat emitted by Earth. Without this insulating blanket, the surface of Earth would actually be frozen. When the concentration of greenhouse gases in the atmosphere increases, more heat is trapped and Earth warms. Carbon dioxide (CO2) is the most significant of the greenhouse gases. Others include water vapor, methane, and nitrous oxide.

How are people causing Earth's climate to change?
Over the last 100 years, human activity is causing global average temperatures to rise. In particular, the burning of fossil fuels (coal, oil, and natural gas) is releasing carbon that had been locked within Earth's geologic reservoir for millions of years. The burning of coal to generate electricity is the most significant source of this CO2. Deforestation also plays a part: trees remove CO2 from the atmosphere through photosynthesis, and when trees burn, the carbon inside them rapidly turns into CO2. Since the Industrial Revolution at the end of the 18th century, concentrations of this greenhouse gas have grown faster and higher than at any time in the past 850,000 years (and probably much longer).

How do we study global climate?
Climate is enormously complex, and scientists have yet to understand how the system operates as a whole. Observations of present-day temperatures and greenhouse gas concentrations made by thermometers, ocean buoys, and satellites are key. Scientists also study the geologic record—information preserved in tree rings, fossil corals, glacial deposits, deep-sea sediments, and glacial ice—to understand how climate has changed in the past. Computer models based on all these observations help them understand what the future may hold.

How does climate change affect our world?

Warmer ocean waters could make storms more powerful.
© Earth Sciences and Image Analysis Laboratory, NASA Johnson Space Center, IAA007-E-10244-2
(click to enlarge)
All living things, from penguins to palm trees, survive only within a particular set of environmental conditions. Even a small change can upset the delicate balance in which species coexist. For example, changing ocean chemistry may kill the coral animals that create tropical reefs. These disturbances ripple through the web that connects all living things, threatening Earth's biodiversity in countless ways. The increase in average global temperatures may also intensify extreme weather events such as droughts and severe storms.

How could climate change affect human society?
While we can use technology to modify our surroundings, humans are not immune to the effects of climate change. Society could be at serious risk. For example, droughts could
disrupt agriculture, causing starvation. Storm surges and rising sea levels could displace the hundreds of millions of people who live on or near seacoasts. Changes in temperatures and the distribution of rainfall could lead to disease outbreaks. The kind of social and economic upheaval that disrupts societies could result. We don't know what's going to happen, but we do have the power to act.

What can we do to address climate change?
The decisions we make affect Earth's climate. These decisions are made at all levels: by individuals, communities, and countries. As individuals, we can use less energy in our homes, schools, and workplaces; recycle and reuse; buy locally grown produce; build energy-efficient "green" buildings; drive less; and reduce our energy use in countless other ways. On a broader scale, governments can encourage the development of non-fossil fuel-based energy sources like solar, wind, and nuclear power; investigate strategies to remove CO2 from the atmosphere; and support sustainable development. While there is no single way to address climate change, people and communities acting together can reduce CO2 emissions. Not acting is the riskiest course of all.

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