Humans Bring On Many Changes, Most Are Far From Painless

From atmospheric changes, to timelapse imagery from Google Earth...our planetary presence is hard to miss. This past week has seen the concentration of carbon dioxide (CO2) in Earth's atmosphere reach a level of 400 parts-per-million, a value the planet hasn't seen since several million years ago. To put this into some kind of context let's take a look at the variation in CO2 over the past half century or so - via the classic ' Keeling Curve '. [More]