The main pillars of climate policy are adaptation to and mitigation of climate change. The primary objective of adaptation policies—in turn—is to make adjustments in ecological, social, or economic systems that prevent adverse impacts (like losses in agricultural yields) of climate change or take advantage of this change (like using an ice-free Northwest Passage, providing a shipping shortcut between the Pacific and Atlantic Oceans). In the case of policies to mitigate climate change, the primary aim is basically climate protection by reducing the emissions of greenhouse gases.