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Climate Change: A look at the latest National Climate Assessment report — and a heads up

Staff report

Thirteen federal agencies released findings this week in a 1,600-page report on climate change. The U.S. Global Change Research Program is a consortium of 13 federal agencies that include the Department of Defense, NASA and the Environmental Protection Agency.

The fourth National Climate Assessment is the latest of required reports on federal research into climate change. Mandated by the Global Change Research Act of 1990, it seeks to assess the environmental, economic, and health and safety consequences of climate change. Three hundred scientists contributed to it.

It builds on a 2017 report in which federal scientists found “it is extremely likely that human influence has been the dominant cause of the observed warming since the mid-20th century.”

The latest report reiterates that “The impacts and costs of climate change are already being felt in the United States and changes in the likelihood of severity of some recent extreme weather events can now be attributed with increasingly higher confidence to human-caused warming.” (V0X)

According to the Vox report, the latest report echoes the same basic themes about climate change”: 1. It’s already happening, 2. It’s going to get worse, 3. It’s going to cost us dearly, and 4. We can still do something about it.

Here are summaries of some of the reporting on the National Climate Assessment report:

Coral Davenport and Kendra Pierre-Louis, The New York Times:

. . . If significant steps are not taken to rein in global warming, the damage will knock as much as 10 percent off the size of the U.S. economy by century’s end.

Wildfires (Wikimedia photos)

In direct language, the 1,656-page assessment lays out the devastating effects of a changing climate on the economy, health and environment, including record wildfires in California, crop failures in the Midwest and crumbling infrastructure in the South.

Going forward, American exports and supply chains could be disrupted, agricultural yields could fall to 1980s levels by midcentury and fire season could spread to the Southeast, the report finds. . .

All told, the report says, climate change could slash up to a tenth of gross domestic product by 2100, more than double the losses of the Great Recession a decade ago. . .

The report puts the most precise price tags to date on the cost to the U.S. economy of projected climate impacts: $141 billion from heat-related deaths, $118 billion from sea level rise and $32 billion from infrastructure damage by the end of the century, among others. . .

the new report also emphasizes that the outcomes depend on how swiftly and decisively the United States and other countries take action to mitigate global warming. The authors put forth three main solutions: putting a price on greenhouse gas emissions, which usually means imposing taxes or fees on companies that release carbon dioxide into the atmosphere; establishing government regulations on how much greenhouse pollution can be emitted; and spending public money on clean-energy research. . .

The report covers every region of the United States and asserts that recent climate-related events are signs of things to come. No area of the country will be untouched, from the Southwest, where droughts will curb hydropower and tax already limited water supplies, to Alaska, where the loss of sea ice will cause coastal flooding and erosion and force communities to relocate, to Puerto Rico and the Virgin Islands, where saltwater will taint drinking water.

More people will die as heat waves become more common, the scientists say, and a hotter climate will also lead to more outbreaks of disease.

Two areas of impact particularly stand out: trade and agriculture.


. . .Extreme weather events driven by global warming are “virtually certain to increasingly affect U.S. trade and economy, including import and export prices and businesses with overseas operations and supply chains,” the report concludes.

Wildfires and air pollution

Such disasters will temporarily shutter factories both in the United States and abroad, causing price spikes for products from apples to automotive parts, the scientists predicted. So much of the supply chain for American companies is overseas that almost no industry will be immune from the effects of climate change at home or abroad, the report says. It cites as an example the extreme flooding in Thailand in 2011. Western Digital, an American company that produces 60 percent of its hard drives there, sustained $199 million in losses and halved its hard drive shipments in the last quarter of 2011. The shortages temporarily doubled hard drive prices, affecting other American companies like Apple, HP and Dell.

American companies should expect many more such disruptions, the report says.. .

Agricultural risks

The nation’s farm belt is likely to be among the hardest-hit regions, and farmers in particular will see their bottom lines threatened.

“Rising temperatures, extreme heat, drought, wildfire on rangelands and heavy downpours are expected to increasingly disrupt agricultural productivity in the U.S.,” the report says. “Expect increases in challenges to livestock health, declines in crop yields and quality and changes in extreme events in the United States and abroad.”

By 2050, the scientists forecast, changes in rainfall and hotter temperatures will reduce the agricultural productivity of the Midwest to levels last seen in the 1980s.

The risks, the report noted, depend on the ability of producers to adapt to changes. During the 2012 Midwestern drought, farmers who incorporated conservation practices fared better, said Robert Bonnie, a Rubenstein Fellow at Duke University who worked in the Agriculture Department during the Obama administration. But federal programs designed to help farmers cope with climate change have stalled because the farm bill, the primary legislation for agricultural subsidies, expired this fall.


The report says the Midwest, as well as the Northeast, will also experience more flooding when it rains, like the 2011 Missouri River flood that inundated a nuclear power plant near Omaha, Nebraska, forcing it to shut down for years.

Other parts of the country, including much of the Southwest, will endure worsening droughts, further taxing limited groundwater supplies. Those droughts can lead to fires, a phenomenon that played out this fall in California as the most destructive wildfire in state history killed dozens of people.

The report predicts that frequent wildfires, long a plague of the western United States, will also become more common in other regions, including the Southeast. The 2016 Great Smoky Mountains wildfires, which killed 14 people and burned more than 17,000 acres in Tennessee, may have been just the beginning. But unlike in the West, “in the Southeast, they have no experience with fires or at least very, very little,” said Andrew Light, a co-author of the report and a senior fellow at the World Resources Institute.
Climate change is taking the United States into uncharted territory, the report concludes. “The assumption that current and future climate conditions will resemble the recent past is no longer valid,” it says.

There is always some uncertainty in climate projections, but scientists’ estimates about the effects of global warming to date have largely been borne out. The variable going forward, the report says, is the amount of carbon emissions humans produce.

The Chicago Tribune

Rising temperatures in the Midwest are projected to be the largest contributing factor to declines in U.S. agricultural productivity, with extreme heat wilting crops and posing a threat to livestock. . .

Midwest farmers will be increasingly challenged by warmer, wetter and more humid conditions from climate change, which also will lead to greater incidence of crop disease and more pests and will diminish the quality of stored grain. During the growing season, temperatures are projected to climb more in the Midwest than in any other region of the U.S., the report says.

Without technological advances in agriculture, the onslaught of high-rainfall events and higher temperatures could reduce the Midwest agricultural economy to levels last seen during the economic downturn for farmers in the 1980s.

Overall, yields from major U.S crops are expected to fall, the reports says. To adapt to the rising temperatures, substantial investments will be required, which will in turn will hurt farmers’ bottom lines. . .

Scientists say human activity is changing the planet’s climate faster than at any point time in modern civilization, heralding costly and, in some cases, life-threatening consequences in every region of the country. Though the monstrous 2017 hurricane season and wildfires in California in recent years may be some of the most visceral images of the devastation a changing climate can wreak, the subtle effects from increasingly unpredictable water availability, more frequent heavy rainfall and hotter weather in the Midwest are just as important, according to Jim Angel, Illinois’ state climatologist, who contributed to Friday’s report. . .

Renewable energy

Meanwhile, William Hohenstein, director of U.S. Department of Agriculture’s climate change program, said the federal government is helping farmers track drought conditions.

“We are working to advance the … drought forecasting,” Hohenstein said. “USDA is also partnering with seed companies to develop new cultivars of crops that are more resilient to drought. To help improve soil health and conserve water, we are providing guidance through our Midwest Regional Climate Hub on conservation practices.”

The report cites other impacts climate change could have on the Midwest.

Warmer air also can hold more moisture, leading to more frequent and severe storms, which would overwhelm aging stormwater systems across the region. Scientists estimate the annual cost of retrofitting urban stormwater systems will exceed $500 million for the Midwest by the end of the century.

Higher temperatures also are expected to lead to diminished air quality. Without policymakers taking steps to mitigate the issue, hotter weather, which is more conducive to smog creation, could result in as many as 550 premature deaths per year by 2050, according to the report. . .

Climate change, once a benign area of research, has become a polarizing and politicized issue in recent years, at times pitting scientists against politicians. . .

* * * *

Vox focused on specific influences of climate change — the frequency and duration of heat waves for one. Deadly temperature spikes this summer killed dozens of people. Virus-spreading mosquitoes are seeing their ranges grow. Lyme-disease-spreading ticks are moving northward. Pollen-spewing plants are making allergy seasons longer and more severe. Air quality is suffering and rising temperatures worsen ground-level ozone which can harm breathing. Extreme rainfall and flooding is more widespread. Large wildfires are more frequent.

Some warming is unavoidable, according to the assessment, so we will have to adapt to higher temperatures, higher sea levels, and more extreme weather.

And we’ll have to have the political will to curb carbon dioxide emissions, shift to cleaner energy, and continue to institute adaptations like water conservation, forest management infrastructure updates, and agricultural advances.

See these additional reports:

NPR: Climate Change is Already Hurting U.S. Communities, Federal Report Says

The Hill: Five major takeaways from the federal climate change report

BBC: Climate change: Report warns of growing impact on US life

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