Cities, states and federal governments are suing oil companies, alleging they're financially responsible for damaging effects of climate change. It could help with costs of adapting to a hotter Earth.
Swedish teenager Greta Thunberg delivered a speech at the United Nations Climate Action Summit calling on world leaders to act to address climate change.
There are fewer than 80 Florida grasshopper sparrows left in the wild. As researchers release more into the wild, there's a fight brewing about whether that's the best plan to save them.
"You have stolen my dreams, and my childhood, with your empty words. And yet I'm one of the lucky ones," activist Greta Thunberg, 16, tells world leaders.