Climate | Union of Concerned Scientists

For over 200 years, humanity has powered itself with fossil fuels like oil and coal. We’ve seen an enormous amount of development and progress—but at an incredible cost.

When burnt, fossil fuels all release carbon dioxide, which acts like a blanket around the earth.

As the amount of carbon dioxide increases, the planet warms up. Sea levels rise. Extreme weather becomes more commonplace. A whole range of impacts—from wildfires, to flooding, to extreme heat and drought—become more likely and more severe.

If we do nothing, these impacts will worsen. Large swaths of the world’s population will likely migrate. Entire island nations may disappear. The magnitude and range of impacts means that almost every human on Earth will be affected, if they’re not already. Low-income communities and people of color will be hit the hardest.

But change is still possible. Science suggests that we can avoid the worst impacts of climate change if we limit warming to under 2ºC. To do so, we need a much cleaner economy by mid-century or sooner. Fossil fuel companies need to stop preventing climate action. And leaders in the United States need to act. You can help.