PhysOrg: If countries and farmers make adjustments in what crops they grow and where, then the effects of climate change on the global economy may not be as severe as feared, a Stanford economist says. Dave Donaldson, an associate professor of economics, wrote in a new policy brief for the Stanford Institute for Economic Policy Research that because of agriculture's small share in total gross domestic product for nations around the world, the expected impact on global GDP could be considerably smaller if...