https://www.nytimes.com/interactive/2018/07/11/climate/summer-nights-warming-faster-than-days-dangerous.html

Nights Are Warming Faster Than
Days. Here’s Why That’s Dangerous.
By KENDRA PIERRE-LOUIS and NADJA POPOVICH JULY 11, 2018

July kicked off with searingly hot temperatures for most Americans this year.

New daily, monthly and all-time record highs were set across the country last week, with more than 100 million people sweating it out under heat warnings or advisories. But the low nighttime temperatures that usually provide a crucial respite from scorching summer days have been more quietly making history.

On July 2, Burlington, Vt., set a record for its hottest overnight temperature as the thermometer refused to budge below 80 degrees Fahrenheit. Four days later, central Los Angeles hit 95 degrees before 11 a.m., already breaking the previous daily record of 94 degrees, before rising to well over 100 in the afternoon.

More of the U.S. is Seeing Extremely Warm Temperatures at Night

Percentage of the United States in which local areas are experiencing
extreme minimum (nighttime) and maximum (daytime) summer temperatures

50% of United States area

50%

Extremely warm

nighttime lows

Extremely warm

daytime highs

40%

40%

30%

30%

20%

20%

10%

10%

1920

1940

1960

1980

2000

1920

1940

1960

1980

2000

Source: National Oceanic and Atmospheric Administration | NOAA defines extremely hot temperatures as those in the top 10 percent for the local period of record.
Nationwide, summer nights have warmed at nearly twice the rate of days, with overnight low temperatures increasing 1.4 degrees Fahrenheit per century since 1895, when national temperature records began, compared to a daytime high increase of 0.7 degrees per century. (Nights have warmed faster than days during other seasons, too.)

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That pattern, which is in keeping with climate change models, is expected to continue as the world warms because of human-caused carbon emissions.

Derek S. Arndt, chief of the climate monitoring division at the National Oceanic and Atmospheric Administration, called the increase in summer nighttime temperatures a “dramatic example” of how small shifts in average temperature can lead to big consequences in the extremes.

california.jpg
An early-July heatwave broke temperature records across Southern California. Mike Blake/Reuters
Warmer Summer Nights
Can ‘Really Be Lethal’
In a typical year, heat waves kill more Americans than any other natural disaster including floods, tornadoes and hurricanes.

While warm summer nights may seem less concerning than scorching afternoons, “the combination of high daytime and high nighttime temperatures can be really lethal because the body doesn’t have a chance to cool down during the nighttime hours,” said Lara Cushing, professor of environmental epidemiology at San Francisco State University.

Those risks are higher in places where temperatures have historically been cooler, like coastal California. There people are less physiologically acclimated (the body can get used to higher temperatures up to a point) and less behaviorally adapted to hot weather.

“A hundred and five degrees in San Francisco is going to have a bigger impact probably than 105 degrees in Houston, Tex., where everybody has air conditioning and people are accustomed to dealing with high temperatures,” Dr. Cushing said.

Older people, the sick, and young children are especially at risk. So are agricultural, construction and other outdoor workers, who can no longer avoid the heat by shifting their hours to work earlier or later in the day. Similarly, homeless people who bear the full brunt of the elements get little relief.

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In cities like Los Angeles, Asian-American, black, and Hispanic residents are more likely to live in hotter parts of the city than white residents because of a complicated range of factors like green spaces, elevation, prevailing winds and proximity to the ocean. Lack of green spaces in some neighborhoods, for example, can exacerbate the heat island effect, a phenomenon in which cities are as much as 22 degrees Fahrenheit warmer than less built-up environments because of of their impervious, heat-absorbing surfaces.

While air conditioning can provide a respite from intense heat, it isn’t a panacea. Air conditioners work by sending hot air outside, adding to the heat island effect. If fossil fuels are used to provide power for air conditioners, it exacerbates climate change. And, increased air conditioner use taxes electrical grids making power failures more likely. In the midst of the recent heatwave, roughly 90,000 Los Angeles area residents lost power because transformers, which help distribute electricity, overheated and failed.

Health officials in Canada estimated that up to 70 people in Quebec may have died from heat-related causes after last week’s heat wave stretched north.

Fed Up With Climate Change, Trees Are Moving North & West

USA TODAY – Doyle Rice – May 18, 2017

It’s getting so hot that even the trees are heading north. Man-made climate change — including warmer temperatures and deviations in rainfall patterns — appears to be one of the reasons tree populations in the eastern U.S. are shifting north and, more surprisingly, west, according to new research.

The shift could even lead to the extinction of certain trees in select forests, the study said.

Overall, the changing climate has pushed trees an average of 20 miles north and 25 miles west over the past 30 years. While the northern shift was expected due to warming temperatures, researchers think the more surprising westward movement could be the result of a change in rainfall patterns.

When researchers analyzed the impact of climate change, they found precipitation had a stronger impact on forests in the short term than temperatures, said lead author Songlin Fei of Purdue University.

The eastern U.S. has gotten warmer over the past few decades, and the Southeast has been trending drier.

Fei said that deciduous trees like oak and maple are primarily moving west, and evergreens are moving north. While trees don’t move, of course, where they sprout can change. Saplings can expand into a new region while older growth dies in another, The Atlantic reported.

Left: Changes in temperature across the eastern U.S. between the recent past (1951–1980) and the study period (1981–2014). Yellow and red areas have warmed, while blue areas have cooled. Right: Changes in precipitation. Blue areas have gotten wetter and brown areas have gotten drier.

One of the more striking examples is the scarlet oak, which in nearly three decades has moved more than 127 miles northwest from the Appalachians, Fei told the Associated Press. Today, its population is reduced in the Southeast and more popular in the Midwest.

“Management actions to increase forest ecosystems’ resilience to climate change should consider the changes in both temperature and precipitation,” the study advised.

Brent Sohngen of Ohio State University, who was not involved in the study, told the AP the findings show “there is no doubt some signature of climate change.” But he added that given the rapid rates of change reported, harvesting, forest fires and other disturbances are probably still playing a more significant role than climate change.

The research, which studied 86 species of trees and was based on the analysis of three decades of data gathered by the U.S. Forest Service, was published in the peer-reviewed journal Science Advances.

A Washington state county filed a lawsuit against the oil and gas industry Thursday for contributing to climate change.

King County’s suit is targeting five fossil fuel companies — BP, Chevron, Exxon Mobil, Royal Dutch and ConocoPhillips — “for knowingly contributing to climate disruptions and putting the residents of King County at greater risk of floods, landslides, ocean acidification, sea level rise, and other impacts,” according to a county statement.

The county, which encompasses Seattle, aims to require those companies to establish an abatement fund to mitigate the effects of climate change on salmon recovery, public health, storm water management and infrastructure.

“The science is undisputable [sic]: climate change is impacting our region today, and it will only cause greater havoc and hardships in the future,” King County Executive Dow Constantine said in a statement.

“The companies that profited the most from fossil fuels should help bear the costs of managing these disasters. Big Oil spent many decades disregarding and dismissing what is our most pressing generational challenge. We must hold these companies accountable as we marshal our resources to protect and preserve what makes this region great.”

The county adds its name to other districts in California, New York and Colorado that have filed similar lawsuits.

On May 24, the U.S. District Court for the Northern District of California will start hearings on whether a suit filed by San Francisco and Oakland should proceed to trial or be dismissed. A similar hearing will take place in New York City in June.

Environmentalist groups are cheering the latest suit. 

Richard Wiles, executive director for the Center for Climate Integrity, called it a “moment of reckoning.”

“The fossil fuel industry is not above the law: oil and gas is a product just like lead, asbestos, and tobacco, where producers can be held liable for damages,” he said in a statement.

But fossil fuel and manufacturing industries are criticizing the suits as baseless targeting.

“Lawsuits targeting manufacturers do nothing to address climate change, but will do plenty to line the pockets of plaintiffs’ attorneys — and in this case, the very same attorneys behind countless other public nuisance lawsuits throughout the country,” said Lindsey de la Torre, executive director of the Manufacturers’ Accountability Project in a statement.

“As history has demonstrated, these lawsuits stand little chance in the courtroom.”

https://www.nrs.fs.fed.us/news/release/resources/cities-communities-losing-tree-cover/