Positive effects of global warming include fewer deaths in winter due to cold weather, lower costs of energy for heating homes and other buildings, and better agricultural production. Additionally, warmer temperatures facilitate sea transportation in the northern parts of the Earth.
In most parts of the world, deaths from cold in winter exceed deaths from heat in summer. Winter temperatures especially impact the poor, who cannot afford to sufficiently heat their homes. A rise of even a few degrees of temperature annually decreases fuel expenditures, saves lives and reduces medical costs. Additionally, many people prefer warmer climates, as evidenced by the tendency of retirees to move to southern locations. Global warming also increases levels of carbon dioxide in the atmosphere. Plants thrive in areas with high carbon dioxide concentrations, and crops that absorb more carbon dioxide may grow larger and have increased yields. Warmer climates also open up land for agricultural use in areas that were previously too cold for farming.
In the north, global warming enables commercial fishing at higher latitudes and opens up previously closed areas for shipping. For instance, the fabled Northwest Passage in northern Canada can become a reality, enabling ocean-going traffic to move from the Pacific Ocean to the Atlantic Ocean and back by a northern route.