Economic and political assessments of climate change have for years helped justify inaction. Now, young environmentalists worldwide are shifting the debate to focus on values, ethics and justice.
Why did Earth's climate rapidly cool 12,800 years ago? Evidence is mounting that a comet or asteroid collision is to blame, with new support coming from the bottom of a South Carolina lake.
People are being guilted out of flying to help reduce carbon emmissions.
Carbon dioxide makes up less than one-twentieth of 1% of Earth's atmosphere. How does this relatively scarce gas control Earth's thermostat?
The United Nations is calling on world governments to step up action against climate change. Can China, the world's biggest carbon emitter, fulfill its pledges?
After eight weeks free from drought and abnormally dry conditions, Colorado is again seeing the spread of drought.
We have all the technologies needed to make the electric grid run on renewables and lower pollution. What are they and what are the barriers to adopting them widely?
Is it fact or fantasy? Could adding dust to the atmophere help with climate change?
If the Amazon rainforest functions as our planet's lungs, what do raging wildfires threaten? An atmospheric scientist explains why the fires, though devastating, won't suffocate life on Earth.
Abnormally dry conditions increase again in Colorado, while this spring's heaving snowmelt helped slightly downstream.