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Rate of Ocean Warming Quadrupled Since Late 20th Century, Study Reveals

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By Roz Pidcock

The buildup of heat-trapping greenhouse gases is warming the upper ocean four times faster than during the period 1960-1990, according to new research.


The paper, published March 10 in the journal Science Advances, is the latest effort to piece together current and historical measurements from ships, self-propelled floats, satellites and even seals to get a global picture of how the oceans are faring under rising temperatures.

Since the 1990s, more heat is finding its way to the deep ocean and there has been no change of pace in ocean warming since 1998, compared with the previous decade, the paper notes.

The study marks a step forward, but the authors said they are concerned about the future of ocean science, given the political climate in the U.S. Dr. John Abraham, professor of thermal sciences at the University of St. Thomas in Minnesota and co-author on the paper, told Carbon Brief:

"We are seeing dramatic cuts planned for climate science. There is every reason to expect these cuts will include ocean-sensing systems."

Big Role to Play

Approximately 93 percent of the heat captured by greenhouse gases in the atmosphere ends up in the ocean. The remaining 7 percent heats the atmosphere and the land and causes ice to melt.

This means it is only by measuring the oceans that scientists can tell how fast the planet is heating and how much it will heat in the future, Abraham told Carbon Brief:

"If you want to know about global warming, you really have to understand ocean warming."

Rosamund Pearce / Carbon Brief

Completing the Picture

But accurately working out how quickly the oceans are warming is a difficult task, partly because of gaps in the historical data. Abraham told Carbon Brief:

"Measuring the oceans is challenging because you need enough sensors, in enough locations, for a long enough time to get a picture of the climate."

Early observations were typically done by commercial and scientific research ships, which means they were limited to developed countries and along shipping routes, the paper explains.

In the 1990s, the World Ocean Circulation Experiment greatly expanded the coverage of ocean temperature records. Since 1992, satellites have helped to infer ocean warming from changes in the height of the sea surface, since seawater expands as it warms.

The quality of ocean measurements stepped up a gear after 2005, with the introduction of ARGO floats, a network of nearly 4,000 free-floating buoys measuring temperature in the top 2,000m of the world's oceans.

Map showing the global coverage of the ARGO network and positions of floats that have delivered data within the last 30 days.ARGO

To get a global picture of what's happening across the huge expanse of global ocean, scientists combine measurements from the ARGO network, ship-based observation systems, buoys tethered to the seafloor and even temperature sensors attached to the heads of seals.

While there is a wealth of data post-2005, there are gaps before then that need filling in.

Scientists typically do this by making a best guess based on measurements taken at other locations nearby. The new study updates this approach, said Dr. Lijing Cheng, associate professor at the Chinese Academy of Sciences and lead author on the paper. He told Carbon Brief:

"Our study offers a new method to solve these problems."

Instead of including stations within 800km of the missing data point, as other studies have, the authors extends this to 2,500km to account for the often greater distance between historical stations. This left fewer gaps unfilled and more ocean accounted for, the paper explains.

The authors were also able to correct for past studies that may have underestimated warming by comparing good data from the ARGO era with sparse observations for the same region taken in the 1960s or 1970s. Prof. Kevin Trenberth, a senior scientist at the U.S. National Center for Atmospheric Research and co-author on the paper, told Carbon Brief:

"It has been amazing how much we have been able to recover in terms of information about ocean heat content from sparse past data."

The new method left the scientists with better-than-90 percent coverage of the oceans from the late 1950s to 2015 and from the sea surface all the way down to a depth of 2,000m.

Warming Signal

The study shows the oceans warmed relatively slowly before 1980 and faster since then. The black line in the graph below from the paper shows how the pace picks up after 1980.

The authors say in the paper that their new estimate is "somewhat greater" than previous reports, including the latest report from the Intergovernmental Panel on Climate Change (IPCC).

Dr. Matt Palmer, expert in sea level and ocean heat content at the UK Met Office, who wasn't involved in the study, told Carbon Brief:

"The paper represents an important refinement to our estimates of ocean heat content change … While the study does not alter our basic understanding, it does suggest that IPCC AR5 reported rates of ocean warming were underestimated by about 10-15%."

Increasingly sophisticated ways to keep tabs on the oceans allow scientists to pinpoint, not only how much heat enters the oceans, but also where it goes when it gets there.

The study shows the speed of warming in the upper ocean, between the surface and 700m, has quadrupled between 1960-1991 and 1992-2015 (slope of blue line, below). More strikingly, perhaps, the deep ocean (700-2000m) is warming nine times faster than in the 60s, 70s and 80s (red line).

Global ocean heat content from 1955 to 2015 for the upper ocean (blue), deep ocean (red) and both together (black). All figures are relative to the 1997-2005 average. Cheng et al., (2017)

No Slowdown

Despite what the study calls a "surge" in research into whether global temperature at the Earth's surface slowed down temporarily in the late 90s and 2000s, the paper is clear that no such change of pace has happened in the oceans. It says:

"Our studies show that there has been no slowdown in global ocean heat content change since 1998 compared with the previous decade."

Looking at solely surface temperature over a decade or so is not a reliable way of to track the rate of global climate change, said Palmer:

"Since ocean heat content continued to increase at a time when the rate of global surface temperature rise slowed down, we can infer that a large part of the 'slowdown' must have originated from ocean heat re-arrangement."

All ocean basins experienced significant warming since 1998, with the greatest warming in the southern oceans, the tropical/subtropical Pacific Ocean and the tropical/subtropical Atlantic Ocean. As the paper puts it:

"The Atlantic Ocean and the southern oceans are the major new heat reservoirs (59%) even though their total area is just 48% that of the global ocean."

Overall, about 32 percent of the extra heat absorbed by the ocean between 1960 and 2005 found its way to the deep ocean. Over the past decade, however, this proportion jumped to 49 percent, indicating that the deep ocean is playing an increasingly important role in ocean warming.

Mystery Explained

Finally, the authors combined their estimate of heat taken up by the oceans between 0-2,000m with a previous estimate of warming below 2,000m.

They found a good match with how much heat they would expect to find in the oceans as a whole, based on the amount of solar radiation entering and leaving the atmosphere since 1985. (Compare the yellow line in the graph below with all of the different shades of blue combined).

This means the mystery of the "missing heat" posed by Trenberth a while back is now effectively solved, suggested Palmer.

Proportion of the top of atmosphere (TOA) radiative imbalance expected to enter the ocean (yellow) with estimates of the ocean heat content at different depth levels (blue shading). Cheng et al., (2017)

A Travesty

Despite the fact that ARGO floats are largely to thank for having such detailed information about the oceans, the scientists behind the study fear for the future of the network. Abraham told Carbon Brief:

"I am not confident that we will have continued coverage. The current system uses state-of-the-art sensors that are spread out across the oceans … It is not clear that there will be continued funding for this absolutely crucial system in the current political climate in the U.S."

The Oceanic and Atmospheric Research program at the National Oceanic and Atmospheric Administration (NOAA) is in line for a 26 percent cut and ocean observation and ARGO come out of that budget, Trenbeth told Carbon Brief. What's more, many other countries provide their contributions as a percentage of the NOAA contribution, he added:

"If NOAA cuts back so do others—and it all goes downhill … Argo is still a research enterprise, not an operational one. It is vulnerable. Such a cutback would be a travesty."

Reposted with permission from our media associate Carbon Brief.

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Guillain-Barre syndrome occurs when the body's own immune system attacks and injures the nerves outside of the spinal cord or brain – the peripheral nervous system. Niq Steele / Getty Images

By Sherry H-Y. Chou, Aarti Sarwal and Neha S. Dangayach

The patient in the case report (let's call him Tom) was 54 and in good health. For two days in May, he felt unwell and was too weak to get out of bed. When his family finally brought him to the hospital, doctors found that he had a fever and signs of a severe infection, or sepsis. He tested positive for SARS-CoV-2, the virus that causes COVID-19 infection. In addition to symptoms of COVID-19, he was also too weak to move his legs.

When a neurologist examined him, Tom was diagnosed with Guillain-Barre Syndrome, an autoimmune disease that causes abnormal sensation and weakness due to delays in sending signals through the nerves. Usually reversible, in severe cases it can cause prolonged paralysis involving breathing muscles, require ventilator support and sometimes leave permanent neurological deficits. Early recognition by expert neurologists is key to proper treatment.

We are neurologists specializing in intensive care and leading studies related to neurological complications from COVID-19. Given the occurrence of Guillain-Barre Syndrome in prior pandemics with other corona viruses like SARS and MERS, we are investigating a possible link between Guillain-Barre Syndrome and COVID-19 and tracking published reports to see if there is any link between Guillain-Barre Syndrome and COVID-19.

Some patients may not seek timely medical care for neurological symptoms like prolonged headache, vision loss and new muscle weakness due to fear of getting exposed to virus in the emergency setting. People need to know that medical facilities have taken full precautions to protect patients. Seeking timely medical evaluation for neurological symptoms can help treat many of these diseases.

What Is Guillain-Barre Syndrome?

Guillain-Barre syndrome occurs when the body's own immune system attacks and injures the nerves outside of the spinal cord or brain – the peripheral nervous system. Most commonly, the injury involves the protective sheath, or myelin, that wraps nerves and is essential to nerve function.

Without the myelin sheath, signals that go through a nerve are slowed or lost, which causes the nerve to malfunction.

To diagnose Guillain-Barre Syndrome, neurologists perform a detailed neurological exam. Due to the nerve injury, patients often may have loss of reflexes on examination. Doctors often need to perform a lumbar puncture, otherwise known as spinal tap, to sample spinal fluid and look for signs of inflammation and abnormal antibodies.

Studies have shown that giving patients an infusion of antibodies derived from donated blood or plasma exchange – a process that cleans patients' blood of harmful antibodies - can speed up recovery. A very small subset of patients may need these therapies long-term.

The majority of Guillain-Barre Syndrome patients improve within a few weeks and eventually can make a full recovery. However, some patients with Guillain-Barre Syndrome have lingering symptoms including weakness and abnormal sensations in arms and/or legs; rarely patients may be bedridden or disabled long-term.

Guillain-Barre Syndrome and Pandemics

As the COVID-19 pandemic sweeps across the globe, many neurologic specialists have been on the lookout for potentially serious nervous system complications such as Guillain-Barre Syndrome.

Though Guillain-Barre Syndrome is rare, it is well known to emerge following bacterial infections, such as Campylobacter jejuni, a common cause of food poisoning, and a multitude of viral infections including the flu virus, Zika virus and other coronaviruses.

Studies showed an increase in Guillain-Barre Syndrome cases following the 2009 H1N1 flu pandemic, suggesting a possible connection. The presumed cause for this link is that the body's own immune response to fight the infection turns on itself and attacks the peripheral nerves. This is called an "autoimmune" condition. When a pandemic affects as many people as our current COVID-19 crisis, even a rare complication can become a significant public health problem. That is especially true for one that causes neurological dysfunction where the recovery takes a long time and may be incomplete.

The first reports of Guillain-Barre Syndrome in COVID-19 pandemic originated from Italy, Spain and China, where the pandemic surged before the U.S. crisis.

Though there is clear clinical suspicion that COVID-19 can lead to Guillain-Barre Syndrome, many important questions remain. What are the chances that someone gets Guillain-Barre Syndrome during or following a COVID-19 infection? Does Guillain-Barre Syndrome happen more often in those who have been infected with COVID-19 compared to other types of infections, such as the flu?

The only way to get answers is through a prospective study where doctors perform systematic surveillance and collect data on a large group of patients. There are ongoing large research consortia hard at work to figure out answers to these questions.

Understanding the Association Between COVID-19 and Guillain-Barre Syndrome

While large research studies are underway, overall it appears that Guillain-Barre Syndrome is a rare but serious phenomenon possibly linked to COVID-19. Given that more than 10.7 million cases have been reported for COVID-19, there have been 10 reported cases of COVID-19 patients with Guillain-Barre Syndrome so far – only two reported cases in the U.S., five in Italy, two cases in Iran and one from Wuhan, China.

It is certainly possible that there are other cases that have not been reported. The Global Consortium Study of Neurological Dysfunctions in COVID-19 is actively underway to find out how often neurological problems like Guillain-Barre Syndrome is seen in hospitalized COVID-19 patients. Also, just because Guillain-Barre Syndrome occurs in a patient diagnosed with COVID-19, that does not imply that it was caused by the virus; this still may be a coincident occurrence. More research is needed to understand how the two events are related.

Due to the pandemic and infection-containment considerations, diagnostic tests, such as a nerve conduction study that used to be routine for patients with suspected Guillain-Barre Syndrome, are more difficult to do. In both U.S. cases, the initial diagnosis and treatment were all based on clinical examination by a neurological experts rather than any tests. Both patients survived but with significant residual weakness at the time these case reports came out, but that is not uncommon for Guillain-Barre Syndrome patients. The road to recovery may sometimes be long, but many patients can make a full recovery with time.

Though the reported cases of Guillain-Barre Syndrome so far all have severe symptoms, this is not uncommon in a pandemic situation where the less sick patients may stay home and not present for medical care for fear of being exposed to the virus. This, plus the limited COVID-19 testing capability across the U.S., may skew our current detection of Guillain-Barre Syndrome cases toward the sicker patients who have to go to a hospital. In general, the majority of Guillain-Barre Syndrome patients do recover, given enough time. We do not yet know whether this is true for COVID-19-related cases at this stage of the pandemic. We and colleagues around the world are working around the clock to find answers to these critical questions.

Sherry H-Y. Chou is an Associate Professor of Critical Care Medicine, Neurology, and Neurosurgery, University of Pittsburgh.

Aarti Sarwal is an Associate Professor, Neurology, Wake Forest University.

Neha S. Dangayach is an Assistant Professor of Neurology and Neurosurgery, Icahn School of Medicine at Mount Sinai.

Disclosure statement: Sherry H-Y. Chou receives funding from The University of Pittsburgh Clinical Translational Science Institute (CTSI), the National Institute of Health, and the University of Pittsburgh School of Medicine Dean's Faculty Advancement Award. Sherry H-Y. Chou is a member of Board of Directors for the Neurocritical Care Society. Neha S. Dangayach receives funding from the Bee Foundation, the Friedman Brain Institute, the Neurocritical Care Society, InCHIP-UConn Center for mHealth and Social Media Seed Grant. She is faculty for emcrit.org and for AiSinai. Aarti Sarwal does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.

Reposted with permission from The Conversation.


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One of the initial reasons social distancing guidelines were put in place was to allow the healthcare system to adapt to a surge in patients since there was a critical shortage of beds, ventilators and personal protective equipment. In fact, masks that were designed for single-use were reused for an entire week in some hospitals.

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By Jake Johnson

Unity Task Forces formed by presumptive Democratic presidential nominee Joe Biden and Sen. Bernie Sanders unveiled sweeping party platform recommendations Wednesday that—while falling short of progressive ambitions in a number of areas, from climate to healthcare—were applauded as important steps toward a bold and just policy agenda that matches the severity of the moment.

"We've moved the needle a lot, especially on environmental justice and upping Biden's ambition," said Sunrise Movement co-founder and executive director Varshini Prakash, a member of the Biden-Sanders Climate Task Force. "But there's still more work to do to push Democrats to act at the scale of the climate crisis."

The climate panel—co-chaired by Rep. Alexandria Ocasio-Cortez (D-N.Y.) and former Secretary of State John Kerry—recommended that the Democratic Party commit to "eliminating carbon pollution from power plants by 2035," massively expanding investments in clean energy sources, and "achieving net-zero greenhouse gas emissions for all new buildings by 2030."

In a series of tweets Wednesday night, Ocasio-Cortez—the lead sponsor of the House Green New Deal resolution—noted that the Climate Task Force "shaved 15 years off Biden's previous target for 100% clean energy."

"Of course, like in any collaborative effort, there are areas of negotiation and compromise," said the New York Democrat. "But I do believe that the Climate Task Force effort meaningfully and substantively improved Biden's positions."

 

The 110 pages of policy recommendations from the six eight-person Unity Task Forces on education, the economy, criminal justice, immigration, climate change, and healthcare are aimed at shaping negotiations over the 2020 Democratic platform at the party's convention next month.

Sanders said that while the "end result isn't what I or my supporters would've written alone, the task forces have created a good policy blueprint that will move this country in a much-needed progressive direction and substantially improve the lives of working families throughout our country."

"I look forward to working with Vice President Biden to help him win this campaign," the Vermont senator added, "and to move this country forward toward economic, racial, social, and environmental justice."

Biden, for his part, applauded the task forces "for helping build a bold, transformative platform for our party and for our country."

"I am deeply grateful to Bernie Sanders for working with us to unite our party and deliver real, lasting change for generations to come," said the former vice president.

On the life-or-death matter of reforming America's dysfunctional private health insurance system—a subject on which Sanders and Biden clashed repeatedly throughout the Democratic primary process—the Unity Task Force affirmed healthcare as "a right" but did not embrace Medicare for All, the signature policy plank of the Vermont senator's presidential bid.

Instead, the panel recommended building on the Affordable Care Act by establishing a public option, investing in community health centers, and lowering prescription drug costs by allowing the federal government to negotiate prices. The task force also endorsed making all Covid-19 testing, treatments, and potential vaccines free and expanding Medicaid for the duration of the pandemic.

"It has always been a crisis that tens of millions of Americans have no or inadequate health insurance—but in a pandemic, it's potentially catastrophic for public health," the task force wrote.

Dr. Abdul El-Sayed, a former Michigan gubernatorial candidate and Sanders-appointed member of the Healthcare Task Force, said that despite major disagreements, the panel "came to recommendations that will yield one of the most progressive Democratic campaign platforms in history—though we have further yet to go."

 

Observers and advocacy groups also applauded the Unity Task Forces for recommending the creation of a postal banking system, endorsing a ban on for-profit charter schools, ending the use of private prisons, and imposing a 100-day moratorium on deportations "while conducting a full-scale study on current practices to develop recommendations for transforming enforcement policies and practices at ICE and CBP."

Marisa Franco, director of immigrant rights group Mijente, said in a statement that "going into these task force negotiations, we knew we were going to have to push Biden past his comfort zone, both to reconcile with past offenses and to carve a new path forward."

"That is exactly what we did, unapologetically," said Franco, a member of the Immigration Task Force. "For years, Mijente, along with the broader immigrant rights movement, has fought to reshape the narrative around immigration towards racial justice and to focus these very demands. We expect Biden and the Democratic Party to implement them in their entirety."

"There is no going back," Franco added. "Not an inch, not a step. We must only move forward from here."

Reposted with permission from Common Dreams.

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