New research suggests humans lived in South America at the same time as now extinct giant sloths, bolstering evidence that people arrived in the Americas earlier than once thought.
In this Click & Learn, students explore factors that contribute to patterns seen in the Keeling Curve: a continuous record of atmospheric CO2 starting in 1958.
This Click & Learn traces the flow of energy from the Sun all the way to cells within organisms. The embedded questions and calculations guide students’ understanding of how energy is distributed through a variety of ecosystems.
Earth desperately needs people to stop burning coal, the biggest single source of greenhouse gases, to avoid the most catastrophic impacts of climate change. But it is the world’s biggest source of fuel for electric power and so many depend on it for their very lives.
Floods in northern India were set off by a break on a Himalayan glacier upstream. Here’s a look at how glaciers and glacial lakes form and why they may sometimes break.