Earth

Chalk up one more way 2020 could be an especially stressful year: The Atlantic hurricane season now threatens to be even more severe than preseason forecasts predicted, and may be one of the busiest on record.
With as many as 25 named storms now expected — twice the average number — 2020 is shaping up to be an “extremely active” season with more frequent, longer and stronger storms, the National Oceanic and Atmospheric Administration warns. Wind patterns and warmer-than-normal seawater have conspired to prime the Atlantic Ocean for a particularly fitful year — although it is not yet clear whether climate change had a hand in creating such hurricane-friendly conditions. “Once the season ends, we’ll study it within the context of the overall climate record,” Gerry Bell, lead seasonal hurricane forecaster at NOAA’s Climate Prediction Center, said during an Aug. 6 news teleconference.
The 2020 hurricane season is already off to a rapid start, with a record-high nine named storms by early August, including two hurricanes. The average season, which runs June through November, sees two named storms by this time of year.
“We are now entering the peak months of the Atlantic hurricane season, August through October,” National Weather Service Director Louis Uccellini said in the news teleconference. “Given the activity we have seen so far this season, coupled with the ongoing challenges that communities face in light of COVID-19, now is the time to organize your family plan and make necessary preparations.”

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Storms get names once they have sustained wind speeds of at least 63 kilometers per hour. In April, forecasters predicted there would be 18 named storms, with half reaching hurricane status (SN: 4/16/20). Now, NOAA anticipates that 2020 could deliver a total of 19 to 25 named storms. That would put this year in league with 2005, which boasted over two dozen named storms including Hurricane Katrina (SN: 8/23/15).
Seven to 11 of this year’s named storms could become hurricanes, including three to six major hurricanes of Category 3 or higher, NOAA predicts. By contrast, the average season brings 12 named storms and six hurricanes, including three major ones.
Given that heightened activity, NOAA projects that 2020 will have an Accumulated Cyclone Energy, or ACE, value between 140 to 230 percent the norm. That value accounts for both the duration and intensity of all a season’s named storms, and seasons that exceed 165 percent the average ACE value qualify as “extremely active.”
Researchers at Colorado State University released a similar prediction on August 5. They foresee  24 named storms in total, 12 of which could be hurricanes, including five major ones. The probability of at least one major hurricane making landfall in the continental United States before the season is up is 74 percent — compared with the average seasonal likelihood of 52 percent, the Colorado State researchers say.
It’s hard to know how many storms in total will make landfall. But “when we do have more activity, there is a [trend] of more storms coming towards major landmasses — coming towards the U.S., coming towards Central America, and the Caribbean, and even sometimes up towards Canada,” says meteorologist Matthew Rosencrans of NOAA’s Climate Prediction Center in College Park, Md.
Two main climate patterns are setting the stage for an extremely intense hurricane season, says Jhordanne Jones, an atmospheric scientist at Colorado State in Fort Collins. Warmer-than-normal sea surface temperatures in the tropical Atlantic are poised to fuel stronger storms. What’s more, there are hints that La Niña may develop around the height of Atlantic hurricane season. La Niña, the flip side of El Niño, is a naturally occurring climate cycle that brings cooler waters to the tropical Pacific, changing wind patterns over that ocean (SN: 1/26/15). The effects of that disturbance in air circulation can be felt across the globe, suppressing winds over the Atlantic that might otherwise pull tropical storms apart. More

Methane levels in the atmosphere are at an all-time high. But curbing emissions of that potent greenhouse gas requires knowing where methane is being released, and why. Now, a global inventory of methane sources reveals the major culprits behind rising methane pollution in the 21st century.
Agriculture, landfill waste and fossil fuel use were the primary reasons that Earth’s atmosphere absorbed about 40 million metric tons more methane from human activities in 2017 than it did per year in the early 2000s. Expanding agriculture dominated methane release in places like Africa, South Asia and Oceania, while increasing fossil fuel use heightened emissions in China and the United States, researchers report online July 14 in Environmental Research Letters.
Methane “is one of the most important greenhouse gases — arguably the second most important after CO2,” says Alexander Turner, an atmospheric scientist who will join the University of Washington in Seattle in 2021.
Although there is far less methane than carbon dioxide in the atmosphere, methane can trap about 30 times as much heat over a century as the same amount of CO2. Tallying methane sources “is really important if you want to understand how the climate is going to evolve,” says Turner, who wasn’t involved in the new study. It can also help prioritize strategies to quell pollution, like consuming less meat to cut down on emissions from cattle ranches and using aircraft or satellites to scout out leaky gas pipelines to fix (SN: 11/14/19).  

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Marielle Saunois, an atmospheric scientist at the Pierre Simon Laplace Institute in Paris, and colleagues cataloged global methane pollution in 2017 — the most recent year with complete data — using atmospheric measurements from towers and aircraft around the world. The isotope, or type of carbon, in methane samples contained clues about its source — such as whether the methane was emitted by the oil and gas industry, or by microbes living in rice paddies, landfills or the guts of belching cattle (SN: 11/18/15). The team compared the 2017 observations with average annual emissions from 2000 to 2006.
In 2017, human activities pumped about 364 million metric tons of methane into the atmosphere, compared with 324 million tons per year, on average, in the early 2000s. About half of that 12 percent increase was the result of expanding agriculture and landfills, while the other half arose from fossil fuels. Emissions from natural sources like wetlands, on the other hand, held relatively steady.
Emissions rose most sharply in Africa and the Middle East, and South Asia and Oceania. Both regions ramped up emissions by 10 million to 15 million metric tons. Agricultural sources, such as cattle ranches and paddy fields, were responsible for a 10-million-ton rise in emissions from South Asia and Oceania and a surge almost as big in Africa, the authors estimate. Emissions swelled by 5 to 10 million tons in China and North America, where fossil fuels drove pollution. In the United States alone, fossil fuels boosted methane release by about 4 million tons.

One region that did not show an uptick in methane was the Arctic. That’s curious, because the Arctic is warming faster than anywhere else in the world, and is covered in permafrost — which is expected to release lots of methane into the air as it thaws, says Tonya DelSontro, an aquatic biogeochemist at the University of Geneva not involved in the work (SN: 7/1/20).
The new findings could mean that the Arctic has not bled much methane into the atmosphere yet — or that scientists have not collected enough data from this remote area to accurately gauge its methane emission trends, DelSontro says (SN: 12/19/16). 
The new methane budget may track emissions only through 2017, but “the atmosphere does not suggest that anything has slowed down for methane emissions in the last two years,” says study coauthor Rob Jackson, an environmental scientist at Stanford University. “If anything, it’s possibly speeding up.” By the end of 2019, the methane concentration in the atmosphere reached about 1,875 parts per billion — up from about 1,857 parts per billion in 2017, according to the U.S. National Oceanic and Atmospheric Administration. More

The planet’s hefty pile of discarded electronics is getting a lot heavier, a new report finds. In 2014, the world collectively tossed an estimated 44.4 million metric tons of unwanted “e-waste” — battery-powered or plug-tethered devices such as laptops, smartphones and televisions. By 2030, that number is projected to grow to about 74.7 million tons, […] More

Australia’s most recent wildfire season was so severe that smoke from the fires reached new heights in the atmosphere — and showed some very weird behavior while it was up there. A particularly intense series of bushfires in southeastern Australia from December 29 to January 4 spurred the formation of huge pyrocumulonimbus, or pyroCb, clouds […] More

As many as 220 million people around the world may be at risk of drinking arsenic-contaminated groundwater, a new study finds. Combining climate, environmental and geologic data with machine learning, researchers made a global map, described in the May 22 Science, that predicts where groundwater arsenic concentrations are likeliest to exceed 10 micrograms per liter, […] More

Human beings have a superpower — sweating. When temperatures rise, beads of sweat exude from our pores and evaporate, releasing energy that cools the skin and keeps our bodies from overheating. This self-cooling mechanism has helped humans spread to every hot and humid corner of the globe. But that sweating superpower has a theoretical upper […] More

In the tug-of-war between coastal melting and inland ice buildup, the meltdown is winning in both Greenland and Antarctica. Initial observations from NASA’s ICESat-2 satellite in 2018 and 2019 reveal how the Greenland and Antarctic ice sheets have changed since the original ICESat mission collected data from 2003 to 2008. Both missions measured the height […] More

When it rains heavily in Hawaii, lava pours from the volcano Kilauea, according to a new study facing strong scrutiny by some volcanologists. Starting in May 2018, the volcano dramatically ramped up its 35-year-long eruption, opening 24 new fissures and shooting fountains of lava 80 meters into the air. Within three months, the volcano had […] More