By George B. Kauffman
(Editor’s note: The sources for the information included herein are available in the online version of this article.)
The latest comprehensive assessment carried out by the Intergovernmental Panel on Climate Change (IPCC) has concluded that “Human influence on the climate system is clear,” a headline statement approved in consensus by all the governments. This influence is destined to have long-lasting consequences for ecosystems. The resulting impacts will continue to be felt for millennia.
The terrestrial impacts of climate change are currently readily apparent and have garnered widespread attention for the public, but the effects of climate change on the oceans have been relatively invisible. However, the world’s oceans provide many crucial services of global significance, all of which come with an increasing price caused by human activities. Any adaption to and mitigation of anthropogenic climate change must take into account its effect on the oceans.
The Nov. 13, 2015, issue of Science magazine, the flagship journal of the American Association for the Advancement of Science, the world’s largest general scientific society, is devoted to “Sea Changes: How Climate Change Is Transforming the Oceans.”
The term climate change usually produces thoughts of rising air temperatures or other atmospheric phenomena such as droughts and extreme storms. However, it is much less often that the parallel changes occurring in the oceans are considered despite their extent and importance.
Climate change in the oceans has many deleterious effects. One is the rise in sea levels, which will continue even if fossil fuel emissions are curtailed. For example, in Malé, the capital of the Maldives, a tropical nation composed of 26 coral atolls in the Indian Ocean, more than 120,000 people live just a meter (about 3.4 feet) above the present sea level and face imminent catastrophe.
Currently, scientists are learning about how previous warm periods changed sea levels and what that past might tell us about the future. To help us cope with the problem, so-called green infrastructure, like planted marshes or oyster reefs, could help to protect low-lying shorelines.
Here are additional deleterious effects of climate change. It creates problems for fisheries as commercially valuable fish stocks move in response to warming seas. The uptake of carbon dioxide (CO2) lowers the pH, making the oceans more acidic, affecting the ability of organisms to create and maintain calcium-based shells and skeletons. Warm-water corals are especially susceptible to these effects and might not survive unless CO2 emissions are greatly reduced.
Climate change impacts are less visible, but the longevity and slow pace of life in the deep oceans make that ecosystem uniquely sensitive to environmental variability. Marine vertebrates at every depth are being affected, as are human beings.
Even if the international negotiations like the recent Paris meetings, we will still be coping with the impacts of climate change for centuries.
George B. Kauffman, Ph.D., chemistry professor emeritus at Fresno State and a Guggenheim Fellow, is a recipient of the American Chemical Society’s George C. Pimentel Award in Chemical Education, the Helen M. Free Award for Public Outreach and the Award for Research at an Undergraduate Institution, and numerous domestic and international honors. In 2002 and 2011, he was appointed a Fellow of the American Association for the Advancement of Science and the American Chemical Society, respectively.