24 April 2010

Ocean Acidification--A Basic Environmental Change

One inevitable long-term change due to humanity's two-century carbon orgy is seen in the chemistry of seawater. An upcoming report from the U.S. National Academy of Sciences reviews the issues (access report summary here, registration required).

Ocean Acidification

The pH of the ocean surface waters is around 8.1. Thus oceans are not acid, they are basic. A better term might be "ocean debasification". Be that as it may, about one-third of the carbon dioxide we have been dumping into the atmosphere over the past 200 years has ended up dissolving in the oceans, increasing their surface pH from 8.2 to 8.1, and model projections show an additional 0.2-0.3 drop by the end of the century, "even under optimistic scenarios". "The rate of this change exceeds any known change in ocean chemistry for at least 800,000 years." Not good.

"Atmospheric CO2 increased over thousands of years during the glacial/interglacial cycles of the past 800,000 years, slow enough for the CaCO3 cycle to compensate and maintain near constant pH." But currently "the concentration of atmospheric CO2 is rising too rapidly for natural, CaCO3-cycle processes to maintain the pH of the ocean. As a consequence, the average pH of the ocean will continue to decrease as the surface ocean absorbs more atmospheric CO2."

"It is currently not known if and how various marine organisms will ultimately acclimate or adapt to the chemical changes resulting from acidification, but existing data suggest that there likely will be ecological winners and losers, leading to shifts in the composition and functioning of many marine ecosystems. It is also not known how these changes will interact with other environmental stressors such as climate change, overfishing, and pollution. Most importantly, despite the potential for socioeconomic impacts to occur in coral reef systems, aquaculture, fisheries, and other sectors, there is not currently enough information to assess these impacts, much less develop plans to mitigate or adapt to them." Like driving fast at night on a curvy road with no headlights.

The NAS report recommends a lot more research funding on this topic, so we will at least have a flashlight to illuminate the road ahead, since it doesn't look like anyone is willing to consider the option of slowing down.

This Wikipedia article gives links to additional information sources.

18 April 2010

A World Without Ice--Book Review

"Ice is a sleeping giant that has been awakened, and if we fail to recognize what has been unleashed, it will be at our peril." (Page 130.)

Henry Pollack's A World Without Ice (Avery/Penguin 2009) is not a bad book, but I can't recommend it wholeheartedly. It has a lot of fascinating information in it, from reliable resources (with footnotes--Pollack is Professor of Geophysics Emeritus in the Department of Geological Sciences at the The University of Michigan). But that information is jumbled together and in a few places repetitive. There is not a well-defined theme, story or argument.

Professor Pollack uses information about the Earth's ice deposits of the past, present and future to tell the story of global climate change. But he does not hesitate to include any other information he has at hand, and his chapters wander.

"Nature's best thermometer, perhaps its most sensitive and unambiguous indicator of climate change, is ice. When ice gets sufficiently warm, it melts. Ice asks no questions, presents no arguments, reads no newspapers, listens to no debates. It is not burdened by ideology and carries no political baggage as it crosses the threshold from solid to liquid. It just melts." (Page 114.) "If at times in the past ice ruled the world, then in the warm centuries of the future, seawater--ice's playmate on the global hydrological seesaw--will be the formidable adversary of human life on Earth." (Page 230.)

Any reader will learn some interesting facts, and hear some convincing arguments about global warming. But Professor Pollock could have benefited from a stricter editor.

08 April 2010

Carbon Dioxide Like Nuclear Waste--It's Forever

If you can't see the video, watch it on YouTube here.