Anyone who keeps up with the science of global warming knows that carbon dioxide alone isn’t the problem. Besides that and the other greenhouse gases (methane and nitrous oxide, for instance) we spew into the atmosphere, there’s also the threat of feedback loops and other mechanisms that could magnify the impact of those pollutants even more.
One of those mechanisms, it turns out, is drought. Which is a real cause for concern, considering how much of the U.S. and other regions of the globe are seeing record-breaking dry weather year after year.
The National Oceanic and Atmospheric Administration (NOAA) this week announced that, using data from its CarbonTracker modeling system, the North American drought in 2002 had as bad an impact on the atmosphere as year’s worth of emissions from 200 million cars.
During 2002, some 45 percent of the U.S. alone experienced “extreme” or “exceptional” drought. Drought means less water for healthy soils, plants and trees, which is bad for global warming because soils, plants and trees are natural carbon sinks. Under normal conditions, they take up about one-third of the carbon dioxide we in the States pump into the air every year. But not during droughts.
The 2002 drought reduced the effectiveness of North America’s natural carbon sinks by half, according to NOAA. That meant that 320 million of the 650 million metric tons of carbon dioxide normally absorbed by vegetation and soil stayed in the air instead.
Considering this year’s drought conditions, it’s likely we’ll soon be hearing similar stats for 2007 carbon absorption rates. As of the end of October, for example, a full two-thirds of the southeastern U.S. was in “moderate” to “exceptional” drought. Parts of Australia, China, South America and southern Africa were also experiencing exceptional drought conditions.
The impact on natural carbon sinks is a concern because it could nullify any actions we take to cut greenhouse gas emissions, according to Wouter Peters, the scientist who led the NOAA study.
“Disruptions to natural carbon uptake can have enormous environmental and economic effects, possibly even erasing efforts to reduce fossil fuel emissions in a given year,” Peters said. “Climate extremes can have a major affect on the amount of carbon dioxide in Earth’s atmosphere.”
If you enjoyed this article, please consider sharing it!
Shirley Siluk Gregory
Shirley Siluk Gregory, a transplanted Chicagoan now living in Northwest Florida, represents the progressive half of Green Options' Red, Green and Blue segment. She holds a bachelor's degree in Geological Sciences from Northwestern University but graduated in 1984, just when the market for geologists was flatter than the Florida landscape. Just as well, though: she had little interest in spending her life either in a laboratory or, heaven forbid, an oil field. So, of course, she went into journalism. After extremely low-paying but fun and educational stints at several suburban Chicago weeklies and dailies, Shirley and her then-boyfriend/now-husband Scott found themselves displaced by a media buyout and spending the next several years working as freelancers. Among their credits: The Chicago Tribune, a publication for the manufactured-housing industry, and Web Hosting Magazine, a now-defunct publication that came and went with the dotcom era. Shirley's always been concerned about nature and conservation (and an avid pack-rat, as her family can attest to), but became even more rabidly interested in the environment primarily due to two factors: the growing signs that global warming was real and threatening, and the birth of her son, Noah, in 2003. Suddenly, the prospect of a world that might not be quite as habitable in 40 or 50 years took on a whole new, and personal, meaning. Living where she lives now also helped light the fire of Shirley's environmental awareness: her hometown was severely damaged by Hurricane Ivan in 2004, and beaten up again by Hurricane Dennis in 2005. That, and the fact that she and her family were vacationing in New Orleans until the day before Katrina -- and spent 12 hours driving home for a trip that normally takes 3 -- has made Shirley deeply appreciate how fragile our lifestyles are, and how dependent they are on sound management of natural resources and sustainable living practices. That's why she's become a passionate reader and writer about all things green and sustainable.
Click on a tab to select how you'd like to leave your comment
- Planetsave
