Government Reports See Climate Change, Carbon Effects Ongoing
A sobering new report from the U.S. Department of Agriculture forecasts the future of a warming planet where crops are more likely to fail, but weeds might thrive, livestock would perish in the summer heat, and droughts would become more frequent in parts of the country.
And the future is now, the document concludes. It says, for instance, that the frequency of forest fires and insect outbreaks related to climate change are already increasing.
In a statement accompanying the release of the report, "The Effects of Climate Change on Agriculture, Land Resources, Water Resources, and Biodiversity in the United States," the department's chief economist, Joe Glauber, said the document would provide "practical information that will help land owners and resource managers make better decisions to address the risks of climate change."
The new report comes a few days after another government agency, the National Oceanic and Atmospheric Administration, announced that newly published research (subscription reqd. for full article) had found evidence for the first time that acidified ocean water had been discovered on the continental shelf of North America. In a statement, NOAA described the ocean acidification process as due to the water absorbing carbon dioxide, a key greenhouse gas, from the atmosphere.
Although the agriculture department was the lead agency producing the new assessment, the document was a product of the U.S. Climate Change Science Program, which integrates research efforts of 13 agencies. Agriculture coordinated the production of the report, which included the work of 38 authors from the federal government, as well as universities and private organizations. The general time line for the report covers a period from the recent past until about 2050.
The Salt Lake Tribune, which reported on the document before its formal release, noted that the findings were not entirely new but that they helped clarify the "profound impacts" that might be in store for much of the country, especially the West, in the coming years.
The agriculture researchers assigned levels of confidence to the various findings ranging from "virtually certain" to "virtually impossible." They gave their second-highest level of confidence, "very likely" to the "overarching conclusion" about the current effects of an altered climate:
"Climate changes -- temperature increases, increasing [carbon dioxide] levels, and altered patterns of precipitation -- are already affecting U.S. water resources, agriculture, land resources and biodiversity. The literature reviewed for this assessment documents many examples of changes in these resources that are the direct result of variability and changes in the climate system, even after accounting for other factors. The number and frequency of forest fires and insect outbreaks are increasing in the interior West, the Southwest and Alaska. Precipitation, stream flow, and stream temperatures are increasing in most of the continental United States. The western United States is experiencing reduced snowpack and earlier peaks of spring runoff. The growth of many crops and weeds is being stimulated. Migration of plant and animal species is changing the composition and structure of arid, polar, aquatic, coastal and other ecosystems."
According to the press statement, some key findings of the report included:
- Grain and oilseed crops would mature more rapidly but higher temperatures would increase the risk of crop failures, particularly if precipitation patterns change.
- Higher temperatures could reduce livestock mortality in the winter, a pattern more than made up for by greater deaths in hotter summers. Livestock and dairy production could also decrease as a result of hotter temperatures.
- Forests in the West, Southwest and Alaska, in addition to being affected by bigger and more frequent fires, are also suffering from insect outbreaks and tree mortality. Those changes are expected to continue.
- Increased drought conditions have occurred in the West and Southwest, in contrast to other parts of the United States.
- Controlling weeds could become more difficult. Elevated carbon dioxide levels help weeds grow more rapidly, and they might also become less vulnerable to herbicides.
There were a few bright spots in the report. It found that younger forests in fertile soils would be more productive in an atmosphere richer in carbon dioxide, and that the growing season has increased by up to two weeks over the past 19 years in temperate latitudes.
On the other hand, it also found rapid rates of Arctic warming that could reduce the snow and ice habitat of polar bears. The bears, of course, were recently declared threatened by the federal government, and remain at the center of a legal dispute Climate Law Update has frequently followed, including this recent story.
Regarding the separate report on ocean changes, Richard W. Spinrad, NOAA's assistant administrator for oceanic and atmospheric research, described the significance of the acidification process in the agency's statement last week:
“Acidification of the Earth’s ocean water could have far-reaching impacts on the health of our near-shore environment, and on the sustainability of ecosystems that support human populations through nourishment and jobs. This research is vital to understanding the processes within the ocean, as well as the consequences of a carbon-rich atmosphere.”
In that same statement, one of the researchers, Richard A. Feely, said the acidification could be "seriously impacting marine life" right now. Added Feely:
“While this absorption provides a great service to humans by significantly reducing the amount of greenhouse gases in the atmosphere and decreasing the effects of global warming, the change in the ocean chemistry affects marine life, particularly organisms with calcium carbonate shells, such as corals, mussels, mollusks, and small creatures in the early stages of the food chain.”
(Photo: Dry soil, Sonora Desert, Mexico; Credit: Wikipedia)
