The Realities of Climate Change
Presnted by: Dr. Peter Brewer and Dr. Jim Barry
Climate change associated with rising carbon dioxide levels in the atmosphere are beginning to have noticeable and significant effects on the Earth system and its marine and terrestrial ecosystems. Effects include rising temperatures on land and in the ocean, contraction of ice sheets, changes in the distribution of rainfall, increased frequency and intensity of storms, acidification of ocean waters by the absorption of excess carbon dioxide, and expansion and intensification of low-oxygen zones of the oceans. Terrestrial and marine ecosystems are responding to changing climate in several ways, such as the migration of species ranges, including human pathogens, shifts in biological productivity on land and in the oceans, and widespread bleaching and loss of coral reefs. While most assume that climate change occurs mostly on land, the oceans actually play a pivotal and dominant role in the climate system, both stabilizing climate by absorbing much (50%) of the CO2 emitted to the atmosphere as well as most (80%) of the excess heat. We provide an overview of changes in the CO2 content of the atmosphere, linkages with global climate and ocean chemistry, then discuss the real and potential consequences of ongoing and future climate change on terrestrial and marine ecosystems and society.