Learn the basics of climate change in under 500 words

How does climate change work?

Certain gases in the air, known as greenhouse gases, dramatically warm the Earth. Without greenhouse gases, the Earth would be below freezing. Scientists have discovered people are causing unnatural warming and other Earth changes by putting more of these gases into the air. Since the extra gases also impact the planet in many other ways aside from ‘global warming’, it is more commonly referred to as ‘climate change’.

"The facts of the matter are this: the planet's climate has changed over the last 30 years, chiefly because of human activities."

-- Dr. Gavin Schmidt, Director of NASA's Goddard Institute for Space Studies, September 2011

For over six decades, scientists have measured a steady buildup of warming gases in the air and have traced them back to human sources such as burned gasoline and coal. Each year, for example, the average American puts the weight of an elephant --about 10,000 pounds-- in heat-trapping gases into the air from driving alone.

How do we know about climate change?

People have caused about 1ºF of unnatural warming by putting greenhouse gases into the air. While it may not sound like much, the extra warming has been linked to some natural disasters such as wildfires in the U.S. and drought in the Mediterranean. Virtually all of the leading scientific organizations, including MIT and NASA, agree that human-caused climate change is a reality and just a few more degrees of warming will increase the risk of intense storms and other weather events.

“The question today is no longer if climate change is happening, but how we can confront the social, economic and health challenges it presents.”

-- Massachusetts Institute of Technology, Joint Program on the Science and Policy of Global Change

The world’s top scientists estimate that if steps are not taken to reduce greenhouse gases, the Earth will warm another 2-5ºF in 30 years, and 5-7ºF by the end of this century.

What are the impacts?

Research is underway all over the world to engineer technologies that produce less greenhouse gases and to adapt the world’s cities and economy to a warmer world. Advancements are already underway: unsubsidized wind power is now competitive with traditional power sources in many states, such as in Iowa and Texas. Since 2008, solar power prices have dropped by more than 80%. Today’s cars go more than twice on a gallon of gas than just a few decades ago-- and car makers are working to make 55 mpg the norm by 2025.

“The time for debating whether climate change is real has passed. It is time for a conversation about what we, as a society, intend to do to address it.”

-- Alan Mulally, CEO of Ford, April 2007

New technologies also mean new business opportunities. Many of the largest companies including Apple, General Motors, and Nike see “tackling climate change [as] one of America's greatest economic opportunities of the 21st century".