By Andrea Vittorio
May 6 — Researchers have issued the “loudest and clearest alarm bell to date” signaling the need for urgent actions to combat climate change in the U.S., the president's science adviser said May 6.
The third and most comprehensive installment of the National Climate Assessment shows that evidence of human-induced climate change is growing stronger as its impacts are increasingly felt across the country.
“Climate change is not a distant threat,” John Holdren, who directs the White House Office of Science and Technology Policy, told reporters on a media call. “It is already affecting every region in the country and key sectors of the economy.”
The extensive assessment looked at current and future climate impacts across eight regions and seven sectors, including water, energy, transportation and agriculture. It was developed over four years by hundreds of climate scientists and technical experts.
Among the likely impacts are increased heat waves and heavy precipitation events in the Northeast as well as decreased water availability in the Southeast, Southwest and Great Plains. Rising temperatures could increase the growing season and crop yields in the Midwest, but that region also would experience more droughts, fires and floods as a result, the assessment said.
One of the most “concerning” climate change-related impacts is sea level rise, Jerry Melillo, chairman of a federal advisory committee for the report, said during the media call.
Global sea level rose about eight inches in the last century and is projected to rise another one foot to four feet in this century, according to the report. These projections are especially concerning for low-lying coastal cities such as Miami, New Orleans and Norfolk.
Coastal leaders are increasingly aware of their high vulnerability to climate change and are developing plans to prepare for potential impacts, though these preparations can be costly, the assessment said.
Cumulative costs to the economy of responding to sea level rise and flooding events alone could be as high as $325 billion by 2100 for four feet of sea level rise, with $130 billion expected to be incurred in Florida and $88 billion in the North Atlantic region, according to the report. Still, the cost of inaction is four times to 10 times greater than the cost associated with preventive hazard mitigation, the report said.
The National Climate Assessment is meant to provide information that policy makers, businesses, individuals and others can use for decision making related to climate change.
“I think the most important part of this report is that it's actionable science,” John Podesta, counselor to the president, said during the media call. The report's regional breakdown can help communities across the country begin to understand what climate changes are happening now and how they can react, he said.
The report, which was the first to look in-depth at climate change response strategies, said planning for adaptation (to address and prepare for impacts) and mitigation (to reduce future climate change, for example, by cutting emissions) is becoming more widespread.
Substantial adaptation planning is occurring in the public and private sectors and at all levels of government, from protecting critical infrastructure to preparing for emergency response and recovery.
The report found that 15 states have adaptation plans, and “another dozen are thinking really hard about it,” Rosina Bierbaum, one of the report's authors, said at a White House launch event. “Industry is analyzing how to protect their supply chains, and water reliability and feedstocks are key.”
“Of the cities we analyzed, about 60 percent are already in the process of doing some adaptation planning,” Bierbaum said.
Few measures, however, have been implemented, and those that have appear to be incremental changes, the report said. This makes measuring the effectiveness of adaptation efforts a challenge, Anthony Janetos, another author of the assessment, said.
“It's all very recent so we don't have a great idea yet about how effective these measures are going to be,” Janetos told Bloomberg BNA.
Meanwhile, the assessment noted several examples of voluntary mitigation efforts happening across the country, such as the Regional Greenhouse Gas Initiative (RGGI).
But these efforts are “insufficient” to avoid increasingly negative social, environmental and economic consequences of climate change, the report said.
Even if greenhouse gas emissions are curtailed, temperatures are expected to increase between 3 degrees and 5 degrees Fahrenheit by the end of the century, according to the report. Temperatures could increase by as much as 10 degrees by the end of the century if emissions continue to increase.
The assessment said some climate change impacts will be “unavoidable” as a result of greenhouse gas emissions already accumulating in the atmosphere. Temperatures in the U.S. have already increased by between 1.3 degrees and 1.9 degrees since 1895, with most of the increase occurring since 1970.
But “it's not too late to change our emissions path,” Melillo said during the White House event.
The assessment said “choices made about emissions in the next few decades will have far-reaching consequences for climate change impacts throughout this century.”
Although the report doesn't offer any policy recommendations, it's expected to help underpin the actions laid out in President Obama's climate plan, unveiled in 2013.
Obama has pledged to cut U.S. greenhouse gas emissions 17 percent by 2020 from 2005 levels through actions such as limits on power plant greenhouse gas emissions, more stringent fuel economy standards and other regulatory approaches.
“The rigorous scientific analysis in the third National Climate Assessment will provide an even more solid foundation for all these efforts,” Podesta said at the White House event.
The president has relied on executive branch authority amid limited appetite in Congress for broad climate legislation.
Members of Congress split along party lines in reacting to the assessment, with Democrats saying the report provided irrefutable evidence that the effects of climate change were already being felt coast-to-coast and affirming a need for immediate, urgent action to address those impacts.
Republicans, however, decried the report as a political document designed to bolster Obama's regulatory agenda while imposing costly mandates on the energy industry.
A report on climate science and climate change impacts is due to Congress every four years under the Global Change Research Act of 1990. Only two reports have been completed since the law passed, one in 2000 and one in 2009.
With assistance from Andrew Childers in Washington
To contact the reporter on this story: Andrea Vittorio in Washington at firstname.lastname@example.org
To contact the editor responsible for this story: Larry Pearl at email@example.com
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