The White House plans to release a major report Tuesday outlining how human-driven climate change is already affecting the environment in the United States and warning of more warming to come, possibly signaling a more aggressive response to the issue from the Obama administration.
The government's report is expected to be the most comprehensive review of climate impacts in the U.S. in over a decade.
An official draft copy of the report, known as the Third National Climate Assessment, argues that climate change is resulting in substantial financial, public health, and ecological costs, from increasingly severe weather to disruption of infrastructure. The report points to droughts in the West and flood-based damage to roads in the East.
It is a "significantly more ambitious effort than previous assessments" in terms of scope and the extent to which the public was engaged, according to the National Resource Council's review of a draft copy of the report.
The last National Climate Assessment was released in 2009.
Many steps are being taken to curb emissions and mitigate impacts of climate change, but the draft of the new report warns that those actions have been insufficient, particularly at the local level.
For example, coastal communities haven't done enough to protect shorelines from rising seas, while many areas in the Southeast and Southwest aren't well prepared for water shortages, the report says.
The assessment shows that "Washington needs to play catch-up to where people are already, because they are already feeling climate-related changes in their own lives," says the Environmental Defense Fund's Eric Pooley.
Pooley, a senior vice president at the New York-based group, said President Obama has been following through on a Climate Action Plan he unveiled last June. The plan aims to set new rules on carbon emissions for new and existing power plants and address methane emissions from the gas industry.
But Pooley says the draft National Climate Assessment proves that plan is "not enough."
The White House, for its part, is preparing to promote this report more rigorously than the last such assessment.
Problems for Americans
The National Climate Assessment is intended to inform the president, Congress, and the public about up-to-date science on climate change and its "effects on U.S. regions and key sectors, now and in the coming decades," according to the National Research Council's review.
The draft report warns that the average temperature across the U.S. has risen 1.5 degrees Fahrenheit since record keeping began in 1895. And 80 percent of that warming has happened since 1980. That climate change has started causing problems for Americans in sectors ranging from construction and transportation to agriculture and forestry to health.
Extreme weather, more wildfires, decreased air quality, insect-borne diseases, and food- and waterborne diseases will take an increasing toll on human health, especially among children, the elderly, and the vulnerable.
"Climate change will, absent other changes, amplify some of the existing health threats the nation now faces," the draft report warns, such as asthma and allergies.
Climate change is also disrupting natural systems and displacing species, the report cautions, which could impact the ability of ecosystems to provide useful "services" like flood control and watershed maintenance.
Extreme weather and sea-level rise are causing damage to buildings, roads, railways, runways, and other facilities in many regions. Climate change is straining water supplies, especially in the West, Southwest, and Southeast. Warming and acidifying oceans are reducing fish stocks.
In addition, "many agricultural regions will experience declines in crop and livestock production from increased stress due to weeds, diseases, insect pests, and other climate change-induced stresses," the draft report says.
The report provides guidance for local officials across the country on how to respond to climate change. It advises coastal jurisdictions on how to prepare for sea-level rise and Western regions on planning for drought and wildfires. (Read "Rising Seas" in National Geographic magazine.)
Steps that federal and local governments have taken to reduce emissions and prepare for the impacts of climate change have been in the right direction, the draft report states. But it says those efforts should be redoubled to stave off the worst impacts.
"The domestic costs of climate change are already high and will increase further if emissions are not controlled," the nonprofit Climate Nexus warns in an analysis of the draft report.
Laurie Geller, director of the National Research Council's review of the National Climate Assessment, criticized earlier versions of the report for not being "clear enough on how climate change interacts with other environmental problems, because it's not occurring in isolation."
But she says later drafts did a better job at putting climate change in a broader context.
Recent episodes of unusual weather across much of the country, such as drought in California and flooding in the Midwest, "are illustrations of the types of risks that we are trying to mitigate against," says Geller.
The National Climate Assessment is an effort of 13 government agencies, including the Environmental Protection Agency, NASA, the Department of the Interior, the Department of Defense, the National Oceanic and Atmospheric Administration, and others.
The report is overseen by a 60-person federal advisory committee, a group of science and business leaders who are meeting to review the draft early Tuesday morning and are expected to submit it shortly after in its final form to the White House.
The report was written by more than 240 scientists and other experts from academia; local, state, and federal government; the private sector; and the nonprofit community. Oil companies and environmental groups weighed in, and more than 4,000 public comments were submitted and responded to during the draft process.
Such reports on the status of climate science are due to the president and Congress every four years according to the Global Change Research Act of 1990.