Gaia giveth even as she taketh away.The warming of the global climate over the past century had melted permafrost and glaciers, shifted rainfall patterns, altered animal migratory routes, disrupted agriculture, drowned cities, and similarly necessitated a thousand thousand adjustments, recalibrations and hasty retreats. But humanity's unintentional experiment with the biosphere had also brought some benefits.Now we could grow oysters in New England.Six hundred years ago, oysters flourished as far north as the Hudson. Native Americans had accumulated vast middens of shells on the shores of what would become Manhattan. Then, prior to the industrial age, there was a small climate shift, and oysters vanished from those waters.Now, however, the tasty bivalves were back, their range extending almost to Maine.The commercial beds of the Cape Cod Archipelago produced shellfish as good as any from the heyday of Chesapeake Bay. Several large wikis maintained, regulated and harvested these beds, constituting a large share of the local economy.But as anyone might have predicted, wherever a natural resource existed, sprawling and hard of defense, poachers would be found.