It took an extra few years and a court order, but the U.S. Climate Change Science Program finally released its comprehensive Scientific Assessment of the Effects of Global Change on the U.S. Back in 1990, Congress recognized that access to the best available scientific information is critical in making climate change policy when it passed the Global Change Research Act. The law created the U.S. Climate Change Science Program and directed it to prepare every four years a “National Assessment of Climate Change Impacts on the United States” that integrates, evaluates, and interprets the findings of the federal government’s climate change research in many areas, including water resources. This information would then be used by the federal government and other policy makers to “understand, assess, predict, and respond” to the impacts of climate change.
The law required submission of the second National Assessment to Congress no later than October 31, 2004. The Bush administration ignored this obligation despite pressure from Congress (led by Senators John Kerry and John McCain). Two years after the deadline, several environmental organizations led by the Center for Biological Diversity filed suit to force the release of the National Assessment. The federal district court, clearly offended by the Bush administration’s failure to comply with the law, ordered the administration to release the assessment by May 31, 2008.
The 261-page assessment (click here to download, it is a large file) appears to be a comprehensive and accurate compilation of climate change research. I of course went right to the section on water resources. The assessment states “[a]lthough climate-related changes have been small compared to … other pressures to date, climate change is expected to result in increasing effects in the future. Although U.S. water management practices are generally quite advanced, particularly in the West, the reliance on past conditions as the foundation for current and future planning and practice will no longer be tenable as climate change and variability increasingly create conditions that are well outside of historical parameters, eroding predictability.” The assessment goes on to describe the predicted impacts on water resources, including:
- loss of snowpack and changes in streamflows in the West
- deteriorating water quality due to loss of oxygen
- increased non-point pollution (runoff)
- warming of rivers and lakes
- salt water intrusion into aquifers
- decreased groundwater recharge in some water-stressed regions
- vulnerability to extended drought
The assessment also notes that the most vulnerable regions will be parts of the West that rely on capturing snowmelt runoff (such as the Columbia and Colorado River systems), portions of California, and the New York area.
For the Great Lakes, the assessment predicts “lower net basin supplies and lake water levels.” It further states: “In the Great Lakes and major river systems across the United States, lower water levels are likely to exacerbate challenges relating to water quality, navigation, recreation, hydropower generation, water transfers, and bi-national relationships.”
This research is all well known by water wonks and certainly not ground-breaking or new (I’ve summarized most of it in a recent article titled “Climate Change and Freshwater Resources” published by the American Bar Association). However, it is very helpful from a policy perspective to have it all summarized and compiled in one government produced report. Policy makers and political leaders will likely take action to respond to the findings of the U.S. Climate Change Science Program. An adaptation policy should begin with the good news and common sense offered in the assessment’s Executive Summary: “Declining per capita (and, in some cases, total) water consumption will help mitigate the impacts of climate change on water resources.”
UPDATE: The U.S. Climate Change Science Program also released its final report on “The effects of climate change on agriculture, land resources, water resources, and biodiversity in the United States.” The section on water resources is very similar to the comprehensive National Assessment discussed above, but with a bit more detail and several nice graphics.