You all know what greenhouse gases are. They are things like carbon dioxide, ozone, nitrous oxide, and methane that have this odd interaction with sunlight: like a greenhouse, they let sunlight in through the atmosphere, yet don't let it bounce back out again. The light and heat are trapped, making the planet warmer.
People have long known trees breathe in carbon dioxide and breathe out oxygen. (This probably explains why plants do well when you talk to them.) This cleans away some of this greenhouse gas.
In what has proven to be a big surprise, a new study in the journal Nature demonstrates that plants also produce methane -- and lots of it.
This may lead to a whole lot of rethinking about the causes of global warming (Yes, it's real. Get used to it.) and what can be done to slow it down.
This article on the National Geographic web site has more.
The illustration is by famed naturalist Charles Harper.