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.
Our Medieval ancestors left us with a biological legacy: Genes that may have helped them survive the Black Death make us more susceptible to certain diseases today.
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.