Every dollar spent has an opportunity cost. Global efforts have pulled 1 billion people out of extreme poverty in the last decade and counting (more than in all of human history). That spending would almost certainly have to be reduced due to the sheer cost of preventing global warming (yes we can raise taxes but the cost is in the trillions, we would have to divert).

I fully believe the science of global warming. But the economics is more complex. It's dangerously naive to think there aren't huge tradeoffs to people suffering now. This is why I dislike single issue voters, even on seemingly positive issues. We're doing miraculous things right now and technology advances are going to make global warming orders of magnitude cheaper to solve in the future.