https://www.sciencemag.org/news/2019/12/warning-ancient-tree-rings-americas-are-prone-catastrophic-simultaneous-droughts Source:   By Paul Voosen, Science Magazine. Excerpt: For 10 years, central Chile has been gripped by unrelenting drought. With 30% less rainfall than normal, verdant landscapes have withered, reservoirs are low, and more than 100,000 farm animals have died. The dry spell has lasted so long that researchers are calling it a “megadrought,” rivaling dry stretches centuries ago. It’s not so different from the decadelong drought that California, some 8000 kilometers away, endured until this year. By analyzing tree ring records, scientists have now found evidence that such tandem droughts are more than a coincidence: They are surprisingly common over the past 1200 years, and they may often share a common cause—an abnormally cool state of the eastern Pacific Ocean known as La Niña. ...Nor is it clear how the drought patterns will change as climate warms. A warming ...

https://www.nytimes.com/2019/12/29/opinion/climate-change-hydroelectric-dam.html Source:    By Macarena Soler, Monti Aguirre and Juan Pablo Orrego, The New York Times (Opinion). Excerpt: ... rivers, like many worldwide, have been threatened by dam projects that aim to provide power for distant cities and mining operations. Only one-third of the world’s 177 longest rivers remain free flowing, and just 21 rivers longer than 1,000 kilometers (621 miles) retain a direct connection to the sea. If we are to arrest global climate change, prevent the toxifying of freshwater sources and do right by all those who depend on rivers for survival, we must return more rivers to their natural state. ...Hydropower is not a clean, green technology. Rivers help regulate an increasingly volatile global carbon cycle by transporting decaying organic material from land to sea, where it settles on the ocean floor. This draws an estimated 200 million tons of carbon out of the air each year....

https://eos.org/articles/what-do-you-get-when-you-cross-a-thunderstorm-with-a-wildfire Source:    By Jenessa Duncombe, Eos/AGU.  Excerpt: There are few things more ominous than a looming thundercloud. Add a wildfire to the mix, and the result can be a towering tempest of thick smoke, smoldering embers, and superheated air. Fire-fueled thunderstorms are naturally occurring weather systems that sometimes spin up as a result of smoke and heat billowing from intense wildfires. These extreme storms, called pyrocumulonimbus (pyroCb), occur infrequently, but when they do they can lead to tragic results. The Making of a Fire Storm [:] Wildfires give off intense heat, forcing large amounts of smoke and hot air to rise. As the mixture moves higher into the troposphere—the lowest layer of Earth’s atmosphere—it cools and expands as the air pressure drops. Moisture in the air soon condenses, forming big puffy clouds called pyrocumulus clouds. When conditions in the atmosphere are ...

https://eos.org/articles/bipartisan-focus-on-energy-innovation-emerges Source:   By Randy Showstack, Eos/AGU. Excerpt: A congressional subcommittee has advanced three energy-related bills that push for technological innovation in geothermal energy development, battery storage, and power grid modernization—innovations that could help to slow greenhouse gas emissions. One of the bills, the Advanced Geothermal Research and Development Act of 2019 (H.R. 5374), “takes important steps toward advancing a woefully underutilized source of energy,” said Rep. Sean Casten (D-Ill.) at the 19 December markup of the legislation by the Subcommittee on Energy of the House Committee on Science, Space, and Technology. ...Geothermal energy, which is literally heat derived from Earth, contributes to just 0.4% of electric power generation in the United States, according to the Energy Information Administration of the U.S. Department of Energy (DOE). Although the United States already generates more ...

https://www.sciencemag.org/news/2019/12/scientists-have-discovered-world-s-oldest-forest-and-its-radical-impact-life Source:   By Colin Barras, Science Magazine. Excerpt: Scientists have discovered the world’s oldest forest in an abandoned quarry near Cairo, New York. The 385-million-year-old rocks contain the fossilized woody roots of dozens of ancient trees. The find marks a turning point in Earth’s history. When trees evolved these roots, they helped pull carbon dioxide (CO 2 ) from the air and lock it away, radically shifting the planet’s climate and leading to the atmosphere we know today. Trees like those at Cairo had a big effect on the ancient climate, says Kevin Boyce, a geoscientist at Stanford University in Palo Alto, California. Deep roots penetrate and break up the rocks within and below the soil. Geologists call this processing “weathering,” and it triggers chemical reactions that pull CO 2 from the atmosphere and turn it into carbonate ions in groundwater. This ...

https://www.nytimes.com/2019/12/18/world/australia/record-heat.html Source:   By Jamie Tarabay, The New York Times. Excerpt: ...A national heat wave, triggered by a confluence of meteorological factors that extends well beyond Australia’s shores, pushed high temperatures across the country on Tuesday to an average of 105.6 degrees, or 40.9 degrees Celsius, breaking the record of 104.5, or 40.3 Celsius, set on Jan. 7, 2013. ...As the temperatures have risen, so has the threat of fires, which have ravaged large swathes of the country and shrouded Sydney in smoke. ...The highest temperature ever recorded in the country was 123 degrees on Jan. 2, 1960, in Oodnadatta, a remote outback town in South Australia. On Wednesday, the hottest place on the continent was Birdsville, Queensland, which reached 117 degrees. Nine of Australia’s 10 warmest years on record have occurred since 2005, with last year the third hottest....

https://www.sciencemag.org/news/2019/12/coral-reefs-suffer-around-world-reefs-french-polynesia-are-thriving Source:   By Elizabeth Pennisi, Science Magazine. Excerpt: In a world where warming seas, pollution, and predation are killing coral around the world, an extensive survey of French Polynesia in 2013 has found a ray of hope. On some atolls there, live coral covered 70% of the reef’s surface; on others, big fish such as grouper and barracuda that have almost disappeared elsewhere were thriving....

https://www.nytimes.com/2019/12/15/climate/cop25-un-climate-talks-madrid.html Source:  By Somini Sengupta, The New York Times. Excerpt: In what was widely denounced as one of the worst outcomes in a quarter-century of climate negotiations, United Nations talks ended early Sunday morning with the United States and other big polluters blocking even a nonbinding measure that would have encouraged countries to adopt more ambitious targets for reducing greenhouse gas emissions next year.   Because the United States is withdrawing from the Paris climate agreement, it was the last chance, at least for some time, for American delegates to sit at the negotiating table at the annual talks — and perhaps a turning point in global climate negotiations, given the influence that Washington has long wielded, for better or worse, in the discussions.The Trump administration used the meeting to push back on a range of proposals, including a mechanism to compensate developing countries for lo...

https://eos.org/articles/scientists-and-activists-examine-need-for-climate-action Source:    By Randy Showstack, Eos/AGU. Excerpt: Scientists shouldn’t have to apologize for being advocates “for a fact-based, objective discourse over what is arguably the greatest threat that we face as a civilization.” For Varshini Prakash, the climate crisis “is obviously very depressing” and “terrifying with the timeline that we’re working on” to curb greenhouse gas emissions. However, Prakash isn’t letting that stop her as she works to organize and mobilize youth and others to stop climate change. She is the cofounder of the Sunrise Movement, an organization that advocates for climate action and supports the Green New Deal initiative. She spoke at a 9 December session at AGU’s Fall Meeting 2019 in San Francisco, Calif., on aligning U.S. energy policy with a 1.5°C climate limit above preindustrial levels. The session included climate scientists and activists....

https://www.nytimes.com/interactive/2019/12/12/climate/texas-methane-super-emitters.html Source:   Jonah M. Kessel, a New York Times visual journalist, and Hiroko Tabuchi, a Times climate reporter, went to West Texas oilfields with a camera that can photograph methane. Excerpt: Immense amounts of methane are escaping from oil and gas sites nationwide, worsening global warming, even as the Trump administration weakens restrictions on offenders....  See also: A Methane Leak, Seen From Space, Proves to Be Far Larger Than Thought - https://www.nytimes.com/2019/12/16/climate/methane-leak-satellite.html

https://www.sciencemag.org/news/2019/12/biologists-think-they-know-why-stunning-hawaiian-plant-vanishing Source:   By Elizabeth Pennisi, Science Magazine. Excerpt: Maui’s silverswords (Argyroxiphium sandwicense subsp. macrocephalum) had been declining for centuries, victims of feral goats and tourists eager to uproot living souvenirs. Even before the silversword was declared a federally threatened species in 1992, conservationists had fenced the barren slopes of their habitat, rid the area of goats, and planted silversword seeds. The efforts seemed to be working until the 1990s, after which the Maui species declined by 60%. Plants that sit farther down the volcano have suffered the most, even though they live in wetter conditions. In 2016, Paul Krushelnycky, an ecologist at the University of Hawaii in Honolulu, noted that this recent drop coincided with more frequent changes in the trade winds, east-to-west winds that flow up the volcano. Increasingly, the trade winds’ cool, mo...

https://www.nytimes.com/2019/12/07/climate/ocean-acidification-climate-change.html Source:   By Kendra Pierre-Louis, The New York Times. Excerpt: The world’s oceans are gasping for breath, a report issued Saturday at the annual global climate talks in Madrid has concluded. The report represents the combined efforts of 67 scientists from 17 countries and was released by the International Union for Conservation of Nature. It found that oxygen levels in the world’s oceans declined by roughly 2 percent between 1960 and 2010. The decline, called deoxygenation, is largely attributed to climate change, although other human activities are contributing to the problem. One example is so-called nutrient runoff, when too many nutrients from fertilizers used on farms and lawns wash into waterways. The decline might not seem significant because, “we’re sort of sitting surrounded by plenty of oxygen and we don’t think small losses of oxygen affect us,” said Dan Laffoley, the principal adviser...

https://www.sciencemag.org/news/2019/12/how-volcanic-eruption-helped-create-modern-scotland Source:   By Sid Perkins, Science Magazine. Excerpt: Over seven terrible years in the 1690s, crops failed, farming villages emptied, and severe famine killed up to 15% of the entire population of Scotland. The so-called Scottish ills (named after the biblical plagues) ushered in an era of crippling economic conditions. Soon after, the formerly independent nation joined Great Britain. Now, researchers suggest volcanic eruptions thousands of kilometers away may have helped spark this political transformation. Scientists have long known that volcanoes can alter Earth’s climate. During large eruptions, light-scattering droplets of sulfuric acid reach the stratosphere and spread around the globe, reflecting some of the Sun’s radiation back into space and cooling the planet. Such cold spells can last from several months to several years—and they can help trigger droughts and crop failures. The...

https://www.nytimes.com/2019/12/05/world/americas/amazon-fires-bolsonaro-photos.html Source:   Photographs and Video by Victor Moriyama, Written by Matt Sandy, The New York Times. Excerpt: Deforestation in the world’s largest rainforest, an important buffer against climate change, has soared under President Jair Bolsonaro of Brazil. ...For months, black clouds had hung over the rainforest as work crews burned and chain-sawed through it. Now the rainy season had arrived, offering a respite to the jungle and a clearer view of the damage to the world. The picture that emerged was anything but reassuring: Brazil’s space agency reported that in one year, more than 3,700 square miles of the Amazon had been razed — a swath of jungle nearly the size of Lebanon torn from the world’s largest rainforest. It was the highest loss in Brazilian rainforest in a decade, and stark evidence of just how badly the Amazon, an important buffer against global warming, has fared in Brazil’s first year ...

https://www.nytimes.com/2019/12/05/climate/california-fire-insurance-climate.html Source:   By Christopher Flavelle and Brad Plumer, The New York Times. Excerpt: California’s wildfires have grown so costly and damaging that insurance companies — a homeowner’s last hope when disaster strikes — have increasingly been canceling people’s policies in fire-prone parts of the state. On Thursday, however, California took the highly unusual step of banning the practice, a decision that exacerbates the insurance industry’s miscalculation of the cost of climate change. The new policy imposes a one-year moratorium preventing insurers from dropping customers in or alongside ZIP codes struck by recent wildfires. The moratorium covers at least 800,000 homes around the state. The state has also asked insurers to voluntarily stop dropping customers anywhere in California because of fire risk for one year....

https://www.nytimes.com/2019/12/04/climate/florida-keys-climate-change.html Source:   By Christopher Flavelle and Patricia Mazzei, The New York Times. Excerpt: KEY WEST, Fla. — Officials in the Florida Keys announced what many coastal governments nationwide have long feared, but few have been willing to admit: As seas rise and flooding gets worse, not everyone can be saved. And in some places, it doesn’t even make sense to try. ...The results released Wednesday focus on a single three-mile stretch of road at the southern tip of Sugarloaf Key, a small island 15 miles up Highway 1 from Key West. To keep those three miles of road dry year-round in 2025 would require raising it by 1.3 feet, at a cost of $75 million, or $25 million per mile. Keeping the road dry in 2045 would mean elevating it 2.2 feet, at a cost of $128 million. To protect against expected flooding levels in 2060, the cost would jump to $181 million....

https://www.nytimes.com/2019/12/04/climate/climate-change-acceleration.html Source:   By Henry Fountain, The New York Times. Excerpt: More devastating fires in California. Persistent drought in the Southwest. Record flooding in Europe and Africa. A heat wave, of all things, in Greenland. Climate change and its effects are accelerating, with climate related disasters piling up, season after season. “Things are getting worse,” said Petteri Taalas, Secretary General of the World Meteorological Organization, which on Tuesday issued its annual state of the global climate report, concluding a decade of what it called exceptional global heat. “It’s more urgent than ever to proceed with mitigation.” ...Seas are warming and rising faster, putting more cities at risk of tidal flooding or worse. Glaciers are melting at a pace many researchers did not expect for decades. The amount of Arctic sea ice has declined so rapidly that the region may see ice-free summers by the 2030s. Even the gro...

https://news.berkeley.edu/2019/12/04/early-climate-modelers-got-global-warming-right-new-report-finds Source:   By Robert Sanders, UC Berkeley News. Excerpt: Climate skeptics have long raised doubts about the accuracy of computer models that predict global warming, but it turns out that most of the early climate models were spot-on, according to a look-back by climate scientists at the University of California, Berkeley, Massachusetts Institute of Technology and NASA. Of 17 climate models published between the early 1970s and the late 2000s, 14 were quite accurate in predicting the average global temperature in the years after publication, said Zeke Hausfather, a doctoral student in UC Berkeley’s Energy and Resources Group and lead author of a new paper analyzing the models. “The real message is that the warming we have experienced is pretty much exactly what climate models predicted it would be as much as 30 years ago,” he said. “This really gives us more confidence that today...

https://www.sciencemag.org/news/2019/12/rivers-could-generate-thousands-nuclear-power-plants-worth-energy-thanks-new-blue Source:   By Robert F. Service, Science Magazine. Excerpt: BOSTON—...A new membrane could unlock the potential of “blue energy,” which uses chemical differences between fresh- and saltwater to generate electricity. If researchers can scale up the postage stamp–size membrane in an affordable fashion, it could provide carbon-free power to millions of people in coastal nations where freshwater rivers meet the sea. ...Blue energy’s promise stems from its scale: Rivers dump some 37,000 cubic kilometers of freshwater into the oceans every year. This intersection between fresh- and saltwater creates the potential to generate lots of electricity—2.6 terawatts, according to one recent estimate, roughly the amount that can be generated by 2000 nuclear power plants. There are several ways to generate power from that mixing. And a couple of blue energy power plants have...

https://www.nytimes.com/2019/12/03/climate/carbon-dioxide-emissions.html Source:   By Brad Plumer, The New York Times. Excerpt: WASHINGTON — Emissions of planet-warming carbon dioxide from fossil fuels hit a record high in 2019, researchers said Tuesday, putting countries farther off course from their goal of halting global warming. The new data contained glimmers of good news: Worldwide, industrial emissions are on track to rise 0.6 percent this year, a considerably slower pace than the 1.5 percent increase seen in 2017 and the 2.1 percent rise in 2018. The United States and the European Union both managed to cut their carbon dioxide output this year, while India’s emissions grew far more slowly than expected. And global emissions from coal, the worst-polluting of all fossil fuels, unexpectedly declined by about 0.9 percent in 2019, although that drop was more than offset by strong growth in the use of oil and natural gas around the world. Scientists have long warned, however,...