White House releases major climate change assessment

The White House on May 6 released the third U.S. National Climate Assessment, considered the most comprehensive scientific assessment ever generated of climate change and its impacts across every region of America and major sectors of the U.S. economy.

Developed over four years by scientists and technical experts — with information gathered from town hall meetings and public-comment opportunities — the report contains findings underscoring the need for urgent action to combat the threats from climate change, say leading environmentalists.

“The National Climate Assessment drives home both the reality of climate change science and the impacts Americans are experiencing right now,” said Ken Berlin of the Climate Reality Project. “As we pay more for groceries in the midst of record-breaking droughts, or rebuild after increasingly extreme weather events, or foot the health care bill for worsening air quality, it is clear that the cost of carbon pollution is real and growing.”

Frances Beinecke, president of the Natural Resources Defense Council, said, “Our leading scientists send a stark message: Climate change is already seriously disrupting our lives, hurting our health and damaging our economy. If we don’t slam the brakes on the carbon pollution driving climate change, we’re dooming ourselves and our children to more intense heat waves, destructive floods and storms, and surging sea levels.”

The assessment includes impacts of climate change in regions across the country:

• Northeast – Maine, New Hampshire, Vermont, Massachusetts, Rhode Island, Connecticut, New York, New Jersey, Delaware, Pennsylvania, Maryland, and District of Columbia. The assessment says communities in the Northeast “are affected by heat waves, more extreme precipitation events and coastal flooding due to sea level rise and storm surge.”

• Southeast and Caribbean – Virginia, W. Virginia, Kentucky, Tennessee, Georgia, Alabama, Arkansas, S. Carolina, N. Carolina, Mississippi, Florida, Louisiana, and the Caribbean Islands: “Decreased water availability, exacerbated by population growth and land-use change, causes increased competition for water in this region. There are also increased risks associated with extreme events such as hurricanes.”

• Midwest – Minnesota, Michigan, Iowa, Indiana, Ohio, Missouri, Illinois, and Wisconsin: “The Midwest’s agricultural lands, forests, Great Lakes, industrial activities, and cities are all vulnerable to climate variability and climate change.” “Longer growing seasons and rising carbon dioxide levels increase yields of some crops, although these benefits have already been offset in some instances by occurrence of extreme events such as heat waves, droughts, and floods.”

• Great Plains – Wyoming, N. Dakota, S. Dakota, Montana, Nebraska, Kansas, Oklahoma, and Texas: The Great Plains region “experiences multiple climate and weather hazards, including floods, droughts, severe storms, tornadoes, hurricanes, and winter storms. In much of the Great Plains, too little precipitation falls to replace that needed by humans, plants and animals. These variable conditions already stress communities and cause billions of dollars in damage. Climate change will add to both stress and costs.” “Rising temperatures lead to increased demand for water and energy and impacts on agricultural practices.”

• Southwest – California, Nevada, Arizona, New Mexico, Utah, and Colorado: “The Southwest is the hottest and driest region in the United States. Climate changes pose challenges for an already parched region that is expected to get hotter and, in its southern half, significantly drier. Increased heat and changes to rain and snowpack will send ripple effects throughout the region… and its critical agriculture sector.” “Drought and increased warming foster wildfires and increased competition for scarce water resources for people and ecosystems.”

• Northwest – Idaho, Oregon, and Washington: “The Northwest’s economy, infrastructure, natural systems, public health, and agriculture sectors all face important climate change related risks. Impacts on infrastructure, natural systems, human health, and economic sectors, combined with issues of social and ecological vulnerability, will unfold quite differently in largely natural areas, like the Cascade Range, than in urban areas like Seattle and Portland or among the region’s many Native American Tribes.” “Changes in the timing of streamflow related to earlier snowmelt reduce the supply of water in summer, causing far-reaching ecological and socioeconomic consequences.”

• Alaska: “Over the past 60 years, Alaska has warmed more than twice as rapidly as the rest of the United States…The state’s largest industries, energy production, mining, and fishing—are all affected by climate change.” “Rapidly receding summer sea ice, shrinking glaciers, and thawing permafrost cause damage to infrastructure and major changes to ecosystems. Impacts on Alaska Native communities increase.”

• Hawaii and Pacific Islands: The U.S. Pacific Islands region “includes more than 2,000 islands spanning millions of square miles of ocean. Rising air and ocean temperatures, shifting rainfall patterns, changing frequencies and intensities of storms and drought, decreasing streamflows, rising sea levels, and changing ocean chemistry will threaten the sustainability of globally important and diverse ecosystems…as well as local communities, livelihoods, and cultures.” “Increasingly constrained freshwater supplies, coupled with increased temperatures, stress both people and ecosystems and decrease food and water security.”

• Coasts: “More than 50 percent of Americans – 164 million people – live in coastal counties, with 1.2 million added each year. …Humans have heavily altered the coastal environment through development, changes in land use, and overexploitation of resources. Now, the changing climate is imposing additional stresses…” “Coastal lifelines, such as water supply infrastructure and evacuation routes are increasingly vulnerable to higher sea levels and storm surges, inland flooding, and other climate-related changes.”

U.S. Rep. Mark Pocan, a Democrat from Wisconsin, responded early to these findings, saying they underscore “the urgent need to take immediate action to begin reversing the threats from climate change. Now, more than ever, we must renew our commitment to being good stewards of our environment, of the air that we breathe and of the water that we drink.”

The assessment also contains findings on the impacts of climate change on health, economy and more:

• Health: “Climate change will, absent other changes, amplify some of the existing health threats the nation now faces. Certain people and communities are especially vulnerable, including children, the elderly, the sick, the poor and some communities of color.”

• Transportation: “Sea level rise, coupled with storm surge, will continue to increase the risk of major coastal impacts on transportation infrastructure, including both temporary and permanent flooding of airports, ports and harbors, roads, rail lines, tunnels and bridges. Extreme weather events currently disrupt transportation networks in all areas of the country; projections indicate that such disruptions will increase. Climate change impacts will increase the total costs to the nation’s transportation systems and their users, but these impacts can be reduced through rerouting, mode change, and a wide range of adaptive actions.”

• Energy: “Extreme weather events are affecting energy production and delivery facilities, causing supply disruptions of varying lengths and magnitudes and affecting other infrastructure that depends on energy supply. …Higher summer temperatures will increase electricity use, causing higher summer peak loads, while warmer winters will decrease energy demands for heating.”

• Water: “Climate change affects water demand and the ways water is used within and across regions and economic sectors. …Changes in precipitation and runoff, combined with changes in consumption and withdrawal, have reduced surface and groundwater supplies in many areas. These trends are expected to continue, increasing the likelihood of water shortages for many uses. Increasing flooding risk affects human safety and health, property, infrastructure, economies, and ecology in many basins across the United States… “

• Agriculture: “Climate disruptions to agriculture have been increasing and are projected to become more severe over this century. Some areas are already experiencing climate-related disruptions, particularly due to extreme weather events. While some U.S. regions and some types of agricultural production will be relatively resilient to climate change over the next 25 years or so, others will increasingly suffer from stresses due to extreme heat, drought, disease, and heavy downpours.”

• Ecosystems: “The capacity of ecosystems to buffer the impacts of extreme events like fires, floods, and severe storms is being overwhelmed. Climate change impacts on biodiversity are already being observed in alteration of the timing of critical biological events such as spring bud burst, and substantial range shifts of many species. In the longer term, there is an increased risk of species extinction. Events such as droughts, floods, wildfires, and pest outbreaks associated with climate change … are already disrupting ecosystems.”

• Oceans: “Ocean waters are becoming warmer and more acidic, broadly affecting ocean circulation, chemistry, ecosystems, and marine life. More acidic waters inhibit the formation of shells, skeletons and coral reefs. Warmer waters harm coral reefs and alter the distribution, abundance, and productivity of many marine species. The rising temperature and changing chemistry of ocean water combine with other stresses, such as overfishing and coastal and marine pollution, to alter marine-based food production and harm fishing communities… “

“This report is one of the most useful tools climate researchers produce for American policymakers,” said Brenda Ekwurzel, a Union of Concerned Scientists senior climate scientist. “There’s so much science that’s relevant for people right now, whether its public health officials dealing with heat waves or coastal managers dealing with sea-level rise.”

More from the assessment:

• Temperature: “U.S. average temperature has increased by 1.3°F to 1.9°F since record keeping began in 1895; most of this increase has occurred since about 1970. The most recent decade was the nation’s warmest on record. Temperatures in the United States are expected to continue to rise.”

• Extreme Weather: “There have been changes in some types of extreme weather events over the last several decades. Heat waves have become more frequent and intense, especially in the West. Cold waves have become less frequent and intense across the nation. There have been regional trends in floods and droughts.”

• Hurricanes: “The intensity, frequency, and duration of North Atlantic hurricanes, as well as the frequency of the strongest (Category 4 and 5) hurricanes, have all increased since the early 1980s.”

• Severe Storms: “Winter storms have increased in frequency and intensity since the 1950s, and their tracks have shifted northward over the United States. Other trends in severe storms, including the intensity and frequency of tornadoes, hail, and damaging thunderstorm winds, are uncertain and are being studied intensively.”

• Precipitation: “Average U.S. precipitation has increased since 1900, but some areas have had increases greater than the national average, and some areas have had decreases.’

• Heavy Downpours: “Heavy downpours are increasing nationally, especially over the last three to five decades. Largest increases are in the Midwest and Northeast. Increases in the frequency and intensity of extreme precipitation events are projected for all U.S. regions.”

• Frost-free Season: “The length of the frost-free season has been increasing nationally since the 1980s, with the largest increases occurring in the western United States, affecting ecosystems and agriculture.

• Ice Melt: “Rising temperatures are reducing ice volume and surface extent on land, lakes, and sea. This loss of ice is expected to continue. The Arctic Ocean is expected to become essentially ice free in summer before mid-century.”

• Sea Level: “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.”

• Ocean Acidification: “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 intensifying impacts on marine ecosystems.”

“The National Climate Assessment paints a bleak picture, but it is a picture we have seen clearly for many years, and we have to act on it now,” said Trip Van Noppen, President of Earthjustice.

Sierra Club executive director Michael Brune said, “Today’s landmark report is a wake-up call that we simply cannot afford to sleep through yet again.”

Brune added, “We applaud the Obama administration for listening to these alarm bells and urge them to continue to take critical, common-sense steps, including the first-ever limits on carbon pollution from power plants. We don’t just have an obligation to future generations to take action now — we will seize an enormous opportunity as we do. By leaving dirty fossil fuels in the ground and continuing the transition to clean energy solutions like wind and solar, we can create good American jobs and power homes and businesses nationwide without polluting our air, water, or climate.”