If you look at the effects on carbon dioxide on plant life in isolation from everything else they're right. On the other hand higher temperatures will slow dow

If you look at the effects on carbon dioxide on plant life in isolation from everything else they're right. On the other hand higher temperatures will slow down growth leading to a small net positive or negative depending on which staple crop we're talking about. And on the gripping hand shifting patterns of rainfall are liable to totally screw everything up in a way that could be totally disastrous but which is very hard to predict. But a reluctance to admit that you're wrong is a big part of human politics. Maybe we can find some way to reframe the issue so that it doesn't seem like a retreat to them?