The argument against addressing climate change always has been fundamentally an economic one: We can't afford the needed disruptions to our fossil fuel-driven society. Now a trio of researchers at UC Berkeley and Stanford have come to the opposite conclusion. In a paper just published in Nature, they find that we can't afford not to address climate change. That's because the phenomenon will have devastating effects on the global economy, reducing average global incomes by nearly one-fourth relative to a world without climate change and widening the gap between rich and poor countries. Lab co-director Solomon Hsiang is among the co-authors of this new paper, which reached its conclusions by taking a new approach to modeling the effect of climate change.