The issue focused on climate change is probably one of the biggest environmental problems facing humanity today," NASA scientist Doug Armstrong told Nature in April. "To save Earth from catastrophic climate change, we must reverse climate change."

Armstrong also argued that scientific studies suggest climate change isn't causing climate changes but rather changing climate trends over time. NASA scientists wrote in Nature Climate Change last month that scientists don't yet know whether climate change caused climate shifts or climate shifts caused climate changes.Having trouble viewing the video? Try