Impacts of global warming on large lakes

摘要

Global warming is now having serious impacts on large lakes (100-1000 km~2 in area). Large lakes are not as sensitive as small lakes (<100 km~2), however, they are more reactive than lakes with surface areas >1000 km~2. We have been studying large lakes of the world and found that some of these are facing a very serious situation. Lake Geneva, between Switzerland and France, has lost almost all oxygen from the hypolimnion over the last two decades. Lake Fuxian in Yunnan Province, China, is also suffering from deoxygenation. Lake Biwa, the largest lake in Japan, appears unaffected to the casual observer, but actually the benthic ecosystem and water quality are deteriorating clue to oxygen depletion year by year. We found that the oxygen depletion and benthic ecosystem changes of these lakes are due to insufficient overturning, a result of global warming rather than increases of organic matter related to eutrophication.