PORTLAND – NASA astronaut Chris Cassidy is keeping his exploration impulses down-to-earth, biking 600 miles across the Amazon to raise awareness about climate change and record its effects.

Great @tucareines photo of the three T25 riders, Osvaldo Stella, Paulo Moutinho, and Chris Cassidy. #TransAmazon25 pic.twitter.com/OsI5IzZBZx

— Team Transamazon+25 (@TransAmazon25) September 23, 2017

Cassidy tells WCSH-TV in Maine, where he grew up, that the world is affected by every action humans take. He is traversing the South American jungle with a team of environmental scientists as part of a documentary.

The Amazon is vital to understanding climate change on a global scale. Scientists say as deforestation destroys more of the massive jungle, there’s less vegetation to absorb carbon. Greenhouse gases that would normally be absorbed are released directly into the atmosphere instead.

The team is biking across the Trans Amazon highway and posting their travels on Twitter under the handle @TransAmazon25.