I'm not sure why you'd assume that. Humans can indeed make big changes to the environment. Typically these are negative, clearing of huge areas of forest, the a

I'm not sure why you'd assume that. Humans can indeed make big changes to the environment. Typically these are negative, clearing of huge areas of forest, the air/smog in China. But perhaps there are positive examples too. And if not, well, we really wouldn't know unless we try. Do we even know enough about climate to know what to try and do though? Its not something I've spent a huge amount of time researching.