"However, I have yet to see convincing proof that humans can effect climate change to this magnitude on a macro scale" Ok, let's start with something easier. Ca

"However, I have yet to see convincing proof that humans can effect climate change to this magnitude on a macro scale" Ok, let's start with something easier. Can we agree on the magnitude of the global changes that humans caused on the extension of forests and on the concentration of CO2 in the atmosphere?