Climate change may be speeding up ocean circulation

Science News

Winds are picking up worldwide, and that is making the surface waters of the oceans swirl a bit faster, researchers report. A new analysis of the ocean’s kinetic energy, measured by thousands of floats around the world, suggests that surface ocean circulation been accelerating since the early 1990s.

Some of that sped-up circulation may be due to naturally recurring ocean-atmosphere patterns, such as the Pacific Decadal Oscillation, researchers report February 5 in Science Advances. But the acceleration is greater than can be attributed to natural variability alone — suggesting that global warming may also be playing a role, says a team led by oceanographer Shijian Hu of the Chinese Academy of Sciences in Qingdao.

The connected system of massive currents that swirl between the world’s oceans, sometimes called the Great Ocean Conveyor Belt, redistributes heat and nutrients around the globe and has a powerful effect on climate. Winds dominate mixing in the surface ocean: Prevailing winds in the tropics, for example, can push water masses aside, allowing deeper, nutrient-rich waters to surge upward.

In the deeper ocean, differences in water density due to salt and heat content keep the currents flowing (SN: 1/4/17). For example, in the North Atlantic Ocean, surface currents carry heat north from the tropics, helping to keep northwestern Europe warm. As the waters arrive at the Labrador Sea, they cool, sink and then flow southward, keeping the conveyor belt humming along.

The Trump administration is cutting back protection for migratory birds
The Conversation

The Trump administration has proposed a new regulation on protecting migratory birds that is a drastic pullback from policies in force for the past 100 years. The draft rule is open for public comment through March 19.

In 1916, amid the chaos of World War I, U.S. President Woodrow Wilson and King George V of Great Britain signed the Migratory Bird Treaty. The Migratory Bird Treaty Act (MBTA) wrote the treaty into U.S. law two years later. These measures protected more than 1,100 migratory bird species by making it illegal to pursue, hunt, take, capture, kill or sell live or dead birds, feathers, eggs and nests, except as allowed by permit or regulated hunting.

This bold move was prompted by the decimation of bird populations across North America. Some 5 million birds – especially waterbirds like egrets and herons – were dying yearly to provide feathers to adorn hats, and the passenger pigeon had just become extinct. Fearing that other species would meet the same fate, national leaders took action.

New Book Food or War Outlines How to Avoid a Soylent Green Future
Scientific American

The global food system is under increasing strain from climate change, water scarcity, and soil and biodiversity loss. History shows that lack of food leads to war. In his frightening book Food or War, published in October 2019, science writer Julian Cribb argues that “on current trends, the existing food system will tend to break down, first regionally and then globally, owing to resource scarcity from the 2020s onward, and especially toward the mid-century--unless there is radical change in the world diet and the means by which we feed ourselves. This will lead to increasing outbreaks of violence and war. Nobody, neither rich nor poor, will escape the consequences.” His book offers a sobering view of our impending future if we continue our business-as-usual approach to climate change and agriculture, but offers creative solutions on how we can avoid a desperate Soylent Green-like future where civilization breaks down due to food scarcity.

History lessons

Drought is civilization's great enemy. More intense droughts due to global warming may be the biggest existential threat civilization faces, because drought impacts the two things we need to live--food and water. When the rains stop and the soil dries up, cities die and civilizations collapse as people abandon lands no longer able to supply them with the food and water they need to live. Cribb’s book begins with some fascinating (and disturbing) history lessons. He documents 25 food conflicts that have led to famine, war, and the deaths of over a million people—mostly caused by drought. For example, China’s drought and famine of 1630 – 31 led to a revolt which caused the collapse of the Ming Dynasty. Another drought in China in the mid nineteenth century led to the Taiping rebellion, which claimed 20 – 30 million lives.

Since 1960, 40 – 60% of armed conflicts have been linked to resource scarcity, and 80% of major armed conflicts occurred in vulnerable dry ecosystems. Hungry people are not peaceful people. In a section titled “Future Food Wars”, Cribb ranks these areas at the highest risk for future food conflicts:

1. South Asia (India, Pakistan, Bangladesh and Sri Lanka)
2. Africa
3. China

Rivers are warming at the same rate as the atmosphere
PHYS ORG

"We were surprised to find that Swiss rivers are warming at 95% of the rate of the surrounding air," says Adrien Michel, a doctoral assistant at the CRYOS lab and the paper's lead author. "The conventional wisdom was that the melting of snow and glaciers and the fact that this water then flowed into lakes were counteracting the effect of warmer air on the Swiss plateau. That's no longer the case."

The researchers also observed a 3% average decrease in discharge over the past 40 years, and a 10% decrease in the last two decades. If this trend continues, summer temperature spikes in rivers and streams are likely to become more severe because of the lower volume of water—especially once the glacial melt process is complete.

Threshold effect

Michel believes that the findings have important implications for weather forecasting and climate change adaptation strategies, not least for plant and wildlife populations. "There's a commonly held belief that one or two degrees of warming won't make much difference," he explains. "The truth is that these ecosystems aren't resilient enough to cope when the temperature exceeds certain thresholds several times a year, especially in summer. A few degrees' warming means we're going to see those thresholds surpassed much more often." In other words, global warming—reaching up to 2°C in winter and 4°C in summer—is placing entire ecosystems under strain. And although moving fish populations to higher ground is one possible solution, Michel argues that such a move has unknown and potentially adverse consequences for the host alpine ecosystem.

Wildfires increase winter snowpack -- but that isn't necessarily a good thing
EurekAlert

"So, we put on our skis and got to work," Maxwell said.

The students would go on to log between 15 and 20 miles of back-country skiing each day in the field, measuring snow depth levels and snow water equivalency at 30 sampling spots within the footprint of the Twitchell Canyon Fire, a 2010 mega-fire that consumed 45,000 acres and was the largest active wildfire in the United States at the time.

The team also measured the presence, height and diameter of trees at each location and whether or not those trees were killed by the fire. After crunching the data, collected over that winter and the next, they found pretty impressive numbers: there was an 85% greater snow depth in areas that burned completely compared to areas that didn't burn at all.

"Fires mean more snow into the system initially because of reduced trees that usually block and hold the snow temporarily on branches," said St. Clair, a professor of plant and wildlife sciences. "It's a really good outcome for north-facing slopes where the snowpack will hold in the shade, but If you've got a south-facing (sun-exposed) aspect with a deep snowpack and a rapid spring melt, now there is a higher chance of erosion, loss of nutrients and potential of flooding for downstream communities. The larger and more severe the wildfire, the increased flood potential for valleys."

The research also revealed a 15% increase in snow-water equivalent -- the amount of water contained within the snowpack -- for every 20% increase in tree mortality in the burned areas.

The findings, recently published in Environmental Research Letters, represent the first study to examine the effects of burn severity on snow accumulation and water equivalence using direct measures. The researchers believe the study has considerable implications for water forecasting, especially given that snow-water resources from mountain watersheds provide fresh water for over 20% of the global human population and more than 65% of Utah's water resources.

Coal plants are closing across the West. Here are the companies sticking with coal
LA Times

The numbers tell the story: There are just 20 coal plants in the continental West whose owners haven’t committed to fully retiring them by specific dates, data compiled by the Sierra Club and additional research by The Times show. That’s compared to 49 coal-burning generating stations with units that are slated for closure or have shut down since 2010.

Coal is being pushed off the power grid by competition from cheaper, cleaner energy sources, as well as rising public alarm about climate change and state policies meant to reduce emissions. Nationally, coal supplied just a quarter of the country’s electricity last year, down from nearly half in 2010, according to the U.S. Energy Information Administration.

Coal’s share has fallen even lower in the West, to about 21% of electricity generation in 2018.

But a handful of western utilities continue to operate coal plants with no plans to decommission them, defying economic and political headwinds, The Times found. …

The 20 western coal plants without retirement dates collectively generated nearly 73 million metric tons of planet-warming carbon dioxide emissions in 2018, counting a few units that have since been closed or scheduled for closure — as much climate pollution as 15 million typical passenger cars.

Those emissions fuel a climate crisis that is contributing to bigger wildfires, hotter heat waves and worsening droughts in California and across the West.

Arctic Permafrost Is Melting so Fast, It's Gouging Holes in the Landscape
EurekAletrt

The UN's Intergovernmental Panel on Climate Change has not considered the phenomenon of thermokarst — the degraded land ravaged by an abrupt thaw. When the permafrost that supports the soil disappears, then hillsides collapse and enormous sinkholes suddenly appear, as Wired reported. The effect runs through meters of permafrost and takes a matter of months or a few years. That upends the traditional models of permafrost thawing, which look at a few centimeters of permafrost melt over several decades. The rapid change to the permafrost shocks the landscape, causing an enormous release of carbon.

"The amount of carbon coming off that very narrow amount of abrupt thaw in the landscape, that small area, is still large enough to double the climate consequences and the permafrost carbon feedback," said study lead author Merritt Turetsky, of the University of Guelph and University of Colorado Boulder, as Wired reported.

The researchers found that abrupt thawing will happen in less than 20 percent of the permafrost zone, "but could affect half of permafrost carbon through collapsing ground, rapid erosion and landslides," the authors wrote in the study.

Not only does an abrupt thaw release carbon, but it also releases a tremendous amount of methane, a potent greenhouse gas. So, while only 5 percent of the permafrost may experience abrupt thaw at one time, the emissions will be equal to a much larger area going through a gradual thaw. This can rapidly change the landscape drastically.

"Forests can become lakes in the course of a month, landslides occur with no warning, and invisible methane seep holes can swallow snowmobiles whole," Turetsky said in a statement from the University of Colorado Boulder. "Systems that you could walk on with regular hiking boots and that were dry enough to support tree growth when frozen can thaw, and now all of a sudden these ecosystems turn into a soupy mess," Turetsky added.

The most worrisome permafrost is the type that holds a lot of water because frozen water takes up more space than water. When it thaws it loses a lot of volume. "Where permafrost tends to be lake sediment or organic soils, the type of earth material that can hold a lot of water, these are like sponges on the landscape," Turetsky said, as Wired reported. "When you have thaw, we see really dynamic and rapid changes."

Koalas found dead on Australia logging plantation
BBC

Dozens of koalas have been found dead or injured at a timber plantation in the Australian state of Victoria, sparking an investigation by officials.

Blue gum trees - an important koala habitat - were harvested from the plantation in December, leaving only a few isolated stands of trees.

Some koalas had starved to death in the remaining trees. Others were apparently killed by bulldozers.

About 80 surviving koalas have been removed and are being cared for.

The deaths come after tens of thousands of koalas were killed in the bushfires that have ravaged Australia. The marsupial is listed as "vulnerable" by Australia's Environment Ministry.

'Australia should be ashamed'

After the plantation was logged in December, reports of hundreds of starving koalas came in, environmental group Friends of the Earth Australia said.

"People apparently witnessed the bulldozing of many dead koalas into slash piles," it said.

The Department of Environment, Land, Water and Planning said it was prepared to prosecute over the incident.

Local resident Helen Oakley, who first raised the alarm on Wednesday, posted a video to Facebook, saying she had seen dead koalas at the site.

"There are koalas lying there dead," she said. "Mothers killed and their little babies. Australia should be ashamed of this. We need help."

Animal protection group Animals Australia said it has sent teams to the site in order to "save as many of these precious animals as possible".

"They're Done": CNBC's Jim Cramer Says Fossil Fuel Industry "In the Death Knell Phase"
Common Dreams

Cramer added that "the world's turned on" the industry as they did with tobacco.

"They're done," Cramer said of fossil fuels on the network's "Squawk Box." "We're starting to see divestment all over the world. We're starting to see... big pension funds saying, 'We not going to own them anymore."

"The world's changed," Cramer continued. While companies like BP still mark profits, "nobody cares," because "new money managers want to appease younger people who believe that you can't ever make a fossil fuel company sustainable."

"You can tell that the world's turned on them, and it's actually kind of happening very quickly," said Cramer. "You're seeing divestiture by a lot of different funds. It's going to be a parade... that says look, 'These are tobacco, and we're not going to own them.' "

Scientists find record warm water in Antarctica, pointing to cause behind troubling glacier melt
Science Daily

A team of scientists has observed, for the first time, the presence of warm water at a vital point underneath a glacier in Antarctica -- an alarming discovery that points to the cause behind the gradual melting of this ice shelf while also raising concerns about sea-level rise around the globe.

"Warm waters in this part of the world, as remote as they may seem, should serve as a warning to all of us about the potential dire changes to the planet brought about by climate change," explains David Holland, director of New York University's Environmental Fluid Dynamics Laboratory and NYU Abu Dhabi's Center for Global Sea Level Change, which conducted the research. "If these waters are causing glacier melt in Antarctica, resulting changes in sea level would be felt in more inhabited parts of the world."

The recorded warm waters -- more than two degrees above freezing -- flow beneath the Thwaites Glacier, which is part of the Western Antarctic Ice Sheet. The discovery was made at the glacier's grounding zone -- the place at which the ice transitions between resting fully on bedrock and floating on the ocean as an ice shelf and which is key to the overall rate of retreat of a glacier.

Thwaites' demise alone could have significant impact globally.

It would drain a mass of water that is roughly the size of Great Britain or the state of Florida and currently accounts for approximately 4 percent of global sea-level rise. Some scientists see Thwaites as the most vulnerable and most significant glacier in the world in terms of future global sea-level rise -- its collapse would raise global sea levels by nearly one meter, perhaps overwhelming existing populated areas.

'Wind Of Madness' Is Sweeping Earth, U.N. Secretary-General Says
npr

"Escalation is back," Guterres said, referring to violence that has flared in Yemen, Libya and elsewhere. And in the midst of problems between rival groups, the U.N. chief said, the world is also facing the effects of a worsening climate crisis, citing the historic wildfires that brought disaster to Australia and record high temperatures in the world's oceans.

Guterres made the remarks Tuesday morning in a speech laying out his priorities for the new year. His chief goal, he said, will be to "break the vicious circles of suffering and conflict and to push for a strong surge of diplomacy for peace."

Noting that 2020 will bring the U.N.'s 75th anniversary, he called on its member nations to listen to "conversations in every corner of the world about the future we want."

"There is no doubt that people have much to say," Guterres said, adding, "The disquiet in streets and squares across the world is proof that people want to be heard. They want world leaders to answer their anxieties with effective action."