National Climate Assessment Pulls No Punches About US Options

(All figures are from the 2014 National Climate Assessment draft.)

Later today (Tuesday, May 6), at 8 a.m. EDT, the National Climate Assessment and Development Advisory Committee of experts meets by conference call to approve the final version of the Third National Climate Assessment. The gist of their message, as Suzanne Goldenberg of The Guardian tells us:

“Climate change has moved from distant threat to present-day danger, and no American will be left unscathed.”

With the headline “Federal Report to Warn Climate Change Is Already Hurting Americans,” National Geographic puts the report in less prophetic, but equally valid terms.

Skeptics of repeated international climate studies should note that the NCA is not “just another UN report,” like the four-part IPCC Fifth Assessment Report or the proceedings of many UN Framework Convention on Climate Change meetings. Today’s analysis is red, white, and blue—the latest US government study of climate change and its impacts. It was first released in draft form in January. And though it originates in a sector different from “What We Know” by the American Association for the Advancement of Science and the popular cable TV series “The Years of Living Dangerously,” it reflects research and conclusions very similar to all the other 2014 prognostications.

Ten Indicators figure from National Climate Assessment draft
NCADAC is empowered to “synthesize… the science and information pertaining to current and future impacts of climate change upon the United States and [also] to provide advice and recommendations” for an ongoing, sustainable national assessment. The periodic National Climate Assessments are designed to summarize our most recent national perspectives on climate change based on an amalgamation of sound, peer-reviewed studies, both from observations made across the country and from climate system models.

The committee has produced a 1,300-page report in fairly plain American English, with concise summaries and some shocking statistical maps and graphs—both lowballed and conservatively high. Athough the two previous assessments surprised many readers, some media reports have characterized this one as “dire.” Here’s the bottom line, as stated in the draft:

“Global climate is changing, and this is apparent across the U.S. in a wide range of observations. The climate change of the past 50 years is due primarily to human activities, predominantly the burning of fossil fuels.

Some extreme weather and climate events have increased in recent decades, and there is new and stronger evidence that many of these increases are related to human activities. Human-induced climate change is projected to continue and accelerate significantly if emissions of heat-trapping gases continue to increase.”

As well as the report release by the executive committee, President Barack Obama has scheduled one-on-one interviews with eight television meteorologists about climate change, according to Andrew Freedman of Mashable. Weather reporters have quietly begun acknowledging climate change links to meteorological phenomena in the past few years. Among the reporters to interview the President are Al Roker, co-anchor of NBC’s Today Show; Ginger Zee, meteorologist on ABC’s Good Morning America; John Morales, chief meteorologist of NBC 6 in Miami, Florida; and Jim Gandy, meteorologist of WLTX-TV in Columbia, South Carolina. Tuesday afternoon, senior White House officials will meet in Washington with a broader group of TV meteorologists and other key “stakeholders” and communicators.

The US Global Change Research Program produced Tuesday’s report by coordinating and integrating climate change research done by 13 Cabinet-level agencies and departments. The series of National Climate Assessments began in 2000, several years late, under the federal Global Change Research Act of 1990. (Look for a brief recap of US national and international participation in climate talks since 1990 after tomorrow’s release.)

Sea ice decline from draft NCA The NCA collects, integrates, and assesses observations and research from around the country, helping to show what is actually happening to the global climate and what it means for peoples’ lives, livelihoods, and future. Nearly 300 authors from the public, private, academic, and nonprofit sectors have contributed to this interagency report.

The positive side to the assessment is its reports on responses we have already made and have in the works to answer new climate challenges, including both adaptation to changes that are already happening and mitigation of changes to come. Unlike its two predecessors, this year’s report explicitly assesses the current state of climate change activities around the nation.

The National Academy of Sciences has reviewed it, and the public submitted more than 4,000 statements during the January 14-April 12 comment period. After revisions, the NCADAC officially submits it today to the Federal Government and publishes it online.

Goldenberg points out that “the findings are expected to guide Obama as he rolls out the next and most ambitious phase of his climate change plan in June—a proposal to cut emissions from the current generation of power plants, America’s largest single source of carbon pollution.”

Structure of the National Climate Assessment

With the understanding that the basic direction of the report remains similar to the draft, especially in its illustrative charts and maps, here’s a statement of purpose and usefulness from the draft report:

“The NCA aims to incorporate advances in the understanding of climate science into larger social, ecological, and policy systems, and with this provide integrated analyses of impacts and vulnerability.  The NCA will help evaluate the effectiveness of our mitigation and adaptation activities and identify economic opportunities that arise as the climate changes.  It will also serve to integrate scientific information from multiple sources and highlight key findings and significant gaps in our knowledge. The NCA aims to help the federal government prioritize climate science investments, and… provide the science that can be used by communities around our Nation try to create a more sustainable and environmentally sound plan for our future.”

The authors analyze climate change impacts on seven sectors:

• Human Health,
• Water,
• Energy,
• Transportation,
• Agriculture,
• Forests, and
• Ecosystems and Biodiversity.

National Climate Assessment Topics range from extreme weather to future water and food supplies and climate-related effects on public health.

The NCADAC also views key impacts regionally, dividing the United States into these 10 areas: Northeast, Southeast and Caribbean, Midwest, Great Plains, Southwest, Northwest, Alaska and the Arctic, Hawai‘i and the Pacific Islands. It examines coasts, oceans, and marine resources along these regions.

Report Findings (direct from the draft National Climate Assessment)

Global climate is changing, and this is apparent across the U.S. in a wide range of observations. The climate change of the past 50 years is due primarily to human activities, predominantly the burning of fossil fuels.

Some extreme weather and climate events have increased in recent decades, and there is new and stronger evidence that many of these increases are related to human activities. Human-induced climate change is projected to continue and accelerate significantly if emissions of heat-trapping gases continue to increase.

Impacts related to climate change are already evident in many sectors and are expected to become increasingly challenging across the nation throughout this century and beyond.

Climate change threatens human health and well-being in many ways, including impacts from increased extreme weather events, wildfire, decreased air quality, diseases transmitted by insects, food, and water, and threats to mental health.

Heavy precipitation figure from National Climate Assessment draftInfrastructure across the U.S. is being adversely affected by phenomena associated with climate change, including sea level rise, storm surge, heavy downpours, and extreme heat.

Reliability of water supplies is being reduced by climate change in a variety of ways that affect ecosystems and livelihoods in many regions, particularly the Southwest, the Great Plains, the Southeast, and the islands of the Caribbean and the Pacific, including the state of Hawai`i.

Extreme drought figure from National Climate Assessment draftAdverse impacts to crops and livestock over the next 100 years are expected. Over the next 25 years or so, the agriculture sector is projected to be relatively resilient, even though there will be increasing disruptions from extreme heat, drought, and heavy downpours. U.S. food security and farm incomes will also depend on how agricultural systems adapt to climate changes in other regions of the world.

Natural ecosystems are being directly affected by climate change, including changes in biodiversity and location of species. As a result, the capacity of ecosystems to moderate the consequences of disturbances such as droughts, floods, and severe storms is being diminished.

Planning for adaptation (to address and prepare for impacts) and mitigation (to reduce emissions) is increasing, but progress with implementation is limited.

Life in the oceans is changing as ocean waters become warmer and more acidic.

Key Messages (direct from the draft National Climate Assessment)

Global climate is changing now and this change is apparent across a wide range of observations. Much of the climate change of the past 50 years is primarily due to human activities.

Global climate is projected to continue to change over this century and beyond. The magnitude of climate change beyond the next few decades depends primarily on the amount of heat-trapping gases emitted globally, and how sensitive the climate is to those emissions.

Observed US Temperature change, figure from National Climate Assessment draftU.S. average temperature has increased by about 1.5°F since record keeping began in 1895; more than 80% of this increase has occurred since 1980. The most recent decade was the nation’s warmest on record. U.S. temperatures are expected to continue to rise. Because human-induced warming is superimposed on a naturally varying climate, the temperature rise has not been, and will not be, smooth across the country or over time.

Frost-free season from draft NCAThe length of the frost-free season (and the corresponding growing season) has been increasing nationally since the 1980s, with the largest increases occurring in the western U.S., affecting ecosystems and agriculture. Continued lengthening of the growing season across the U.S. is projected.

Precipitation averaged over the entire U.S. has increased during the period since 1900, but regionally some areas have had increases greater than the national average, and some areas have had decreases. The largest increases have been in the Midwest, southern Great Plains, and Northeast. Portions of the Southeast, the Southwest, and the Rocky Mountain states have experienced decreases. More winter and spring precipitation is projected for the northern U.S., and less for the Southwest, over this century.

Heavy downpours are increasing in most regions of the U.S., especially over the last three to five decades. Largest increases are in the Midwest and Northeast. Further increases in the frequency and intensity of extreme precipitation events are projected for most U.S. areas.

Certain types of extreme weather events have become more frequent and intense, including heat waves, floods, and droughts in some regions. The increased intensity of heat waves has been most prevalent in the western parts of the country, while the intensity of flooding events has been more prevalent over the eastern parts. Droughts in the Southwest and heat waves everywhere are projected to become more intense in the future.

There has been an increase in the overall strength of hurricanes and in the number of strong (Category 4 and 5) hurricanes in the North Atlantic since the early 1980s. The intensity of the strongest hurricanes is projected to continue to increase as the oceans continue to warm; ocean cycles will also affect the amount of warming at any given time. With regard to other types of storms that affect the U.S., winter storms have increased slightly in frequency and intensity, and their tracks have shifted northward over the U.S. Other trends in severe storms, including the numbers of hurricanes and the intensity and frequency of tornadoes, hail, and damaging thunderstorm winds are uncertain and are being studied intensively.

Sea level rise from NCA draft
Global sea level has risen by about 8 inches since reliable record keeping began in 1880. It is projected to rise another 1 to 4 feet by 2100.

Rising temperatures are reducing ice volume and extent on land, lakes, and sea. This loss of ice is expected to continue.

The oceans are currently absorbing about a quarter of the carbon dioxide emitted to the atmosphere annually and are becoming more acidic as a result, leading to concerns about potential impacts on marine ecosystems.

Ocean acidification from NCA draft

3 thoughts on “National Climate Assessment Pulls No Punches About US Options”

  1. I’m actually excited to move beyond the debate whether or not climate change is real–it’s obvious now that it is. Now we’re beginning, I think, to come together as a global community to begin thinking up ways and taking action to solve or mitigate the effects of this coming global catastrophe.

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