Oceans Have Retained Far More Heat Than Previously Believed

'We Have Less Time Than We Thought': Alarming New Study Shows Oceans Have Retained Far More Heat Than Previously Believed

"The planet warmed more than we thought. It was hidden from us just because we didn't sample it right. But it was there. It was in the ocean already."

Commondreams,

31 October, 2018

Offering a stark warning that humanity may have even less time to drastically cut carbon emissions than the United Nations suggested in its latest alarming report on the climate crisis, new research (pdf) published in the journal Nature on Wednesday shows that Earth's oceans have retained 60 percent more heat each year over the past 25 years than scientists previously believed.

"We thought that we got away with not a lot of warming in both the ocean and the atmosphere for the amount of CO2 that we emitted. But we were wrong," Laure Resplandy, a geoscientist at Princeton University who led the new study, toldthe Washington Post. "The planet warmed more than we thought. It was hidden from us just because we didn't sample it right. But it was there. It was in the ocean already."

The U.N.'s Intergovernmental Panel on Climate Change argued in its report released earlier this month that humanity must cut carbon emissions in half by 2030 in order to avert climate catastrophe by 2040—but that timeframe was based on previous and possibly conservative estimates of global warming.

As the Post's Chris Mooney and Brady Dennis noted, "higher-than-expected amount of heat in the oceans means more heat is being retained within Earth's climate system each year, rather than escaping into space."

"In essence," they added, "more heat in the oceans signals that global warming is more advanced than scientists thought."

In a statement on Wednesday, Sierra Club executive director Michael Brune argued that the new research "confirms that we have even less time to move beyond dirty fossil fuels like coal, oil, and fracked gas to an economy powered by 100 percent clean, renewable energy."

"The world's oceans are the canaries in the coal mine when it comes to the climate crisis. The writing has been on the wall for years," Brune said. "This global crisis demands nothing less than swift and meaningful action by every world leader to ensure a safe and healthy future for all. The Trump administration's continued ignorance and lack of action is wholly unacceptable, and together with our allies across the country, we will work toward a brighter, healthier, and safer future for all."

Startling new research finds large buildup of heat in the oceans, suggesting a faster rate of global warming

The findings mean the world might have less time to curb carbon emissions.

The world’s oceans have been soaking up far more excess heat in recent decades than scientists realized, suggesting that Earth could be set to warm even faster than predicted in the years ahead, according to new research published Wednesday.

Over the past quarter-century, Earth’s oceans have retained 60 percent more heat each year than scientists previously had thought, said Laure Resplandy, a geoscientist at Princeton University who led the startling study published Wednesday in the journal Nature. The difference represents an enormous amount of additional energy, originating from the sun and trapped by Earth’s atmosphere — the yearly amount representing more than eight times the world’s annual energy consumption.

In the scientific realm, the new findings help resolve long-running doubts about the rate of the warming of the oceans before 2007, when reliable measurements from devices called “Argo floats” were put to use worldwide. Before that, differing types of temperature records — and an overall lack of them — contributed to murkiness about how quickly the oceans were heating up.

The higher-than-expected amount of heat in the oceans means more heat is being retained within Earth’s climate system each year, rather than escaping into space. In essence, more heat in the oceans signals that global warming is more advanced than scientists thought.

“We thought that we got away with not a lot of warming in both the ocean and the atmosphere for the amount of CO2 that we emitted,” said Resplandy, who published the work with experts from the Scripps Institution of Oceanography and several other institutions in the United States, China, France and Germany. “But we were wrong. The planet warmed more than we thought. It was hidden from us just because we didn’t sample it right. But it was there. It was in the ocean already.”

Wednesday’s study also could have important policy implications. If ocean temperatures are rising more rapidly than previously calculated, that could leave nations even less time to dramatically cut the world’s emissions of carbon dioxide, in the hope of limiting global warming to the ambitious goal of 1.5 degrees Celsius (2.7 degrees Fahrenheit) above preindustrial levels by the end of this century.

The world already has warmed one degree Celsius (1.8 degrees Fahrenheit) since the late 19th century. Scientists backed by the United Nations reported this month that with warming projected to steadily increase, the world faces a daunting challenge in trying to limit that warming to only another half-degree Celsius. The group found that it would take “unprecedented” action by leaders across the globe over the coming decade to even have a shot at that goal.

Meanwhile, the Trump administration has continued to roll back regulations aimed at reducing carbon emissions from vehicles, coal plants and other sources and has said it intends to withdraw from the Paris climate accord. In one instance, the administration relied on an assumption that the planet will warm a disastrous seven degrees Fahrenheit, or about four degrees Celsius, by the end of the century in arguing that a proposal to ease vehicle fuel-efficiency standards would have only minor climate impacts.

The new research underscores the potential consequences of global inaction. Rapidly warming oceans mean that seas will rise faster and that more heat will be delivered to critical locations that already are facing the effects of a warming climate, such as coral reefs in the tropics and the ice sheets of Greenland and Antarctica.

“In case the larger estimate of ocean heat uptake turns out to be true, adaptation to — and mitigation of — our changing climate would become more urgent,” said Pieter Tans, who is the leader of the Carbon Cycle Greenhouse Gases Group at the National Oceanic and Atmospheric Administration and was not involved in the study.

The oceans absorb more than 90 percent of the excess energy trapped within the world’s atmosphere.

The new research does not measure the ocean’s temperature directly. Rather, it measures the volume of gases, specifically oxygen and carbon dioxide, that have escaped the ocean in recent decades and headed into the atmosphere as it heats up. The method offered scientists a reliable indicator of ocean temperature change because it reflects a fundamental behavior of a liquid when heated.

“When the ocean warms, it loses some gas to the atmosphere,” Resplandy said. “That’s an analogy that I make all the time: If you leave your Coke in the sun, it will lose the gas.”

This approach allowed researchers to recheck the contested history of ocean temperatures in a different and novel way. In doing so, they came up with a higher number for how much warming the oceans have experienced over time.

“I feel like this is a triumph of Earth-system science. That we could get confirmation from atmospheric gases of ocean heat content is extraordinary,” said Joellen Russell, a professor and oceanographer at the University of Arizona. “You’ve got the A team here on this paper.”

But Russell said the findings are hardly as uplifting.

The report “does have implications for climate sensitivity, meaning, how warm does a certain amount of CO2 make us?” Russell said, adding that the world could have a smaller “carbon budget” than once thought. That budget refers to the amount of carbon dioxide humans can emit while still being able to keep warming below dangerous levels.

The scientists calculated that because of the increased heat already stored in the ocean, the maximum emissions that the world can produce while still avoiding a warming of two degrees Celsius (3.6 Fahrenheit) would have to be reduced by 25 percent. That represents a very significant shrinkage of an already very narrow carbon “budget.”

The U.N. panel of climate scientists said recently that global carbon emissions must be cut in half by 2030 if the world hopes to remain beneath 1.5 Celsius of warming. But Resplandy said that the evidence of faster-warming oceans “shifts the probability, making it harder to stay below the 1.5-degree temperature target."

Understanding what is happening with Earth’s oceans is critical, because they, far more than the atmosphere, are the mirror of ongoing climate change.

According to a major climate report released last year by the U.S. government, the world’s oceans have absorbed about 93 percent of the excess heat caused by greenhouse gases since the mid-20th century. Scientists have found that ocean heat has increased at all depths since the 1960s, while surface waters also have warmed. The federal climate report projected a global increase in average sea surface temperatures of as much as nearly five degrees Fahrenheit by 2100 if emissions continue unabated, with even higher levels of warming in some U.S. coastal regions.

The world’s oceans also absorb more than a quarter of the carbon dioxide emitted annually from human activities — an effect making them more acidic and threatening fragile ecosystems, federal researchers say. “The rate of acidification is unparalleled in at least the past 66 million years,” the government climate report stated.

Paul Durack, a research scientist at the Lawrence Livermore National Laboratory in California, said Wednesday’s study offers “a really interesting new insight” and is “quite alarming.”

The warming found in the study is “more than twice the rates of long-term warming estimates from the 1960s and ’70s to the present,” Durack said, adding that if these rates are validated by further studies, “it means the rate of warming and the sensitivity of the Earth’s system to greenhouse gases is at the upper end.” He said that if scientists have underestimated the amount of heat taken up by the oceans, “it will mean we need to go back to the drawing board” on the aggressiveness of mitigation actions the world needs to take promptly to limit future warming.

Beyond the long-term implications of warmer oceans, Russell added that in the short term, even small changes in ocean temperatures can affect weather in specific places. For instance, scientists have said warmer oceans off the coast of New England have contributed to more-intense winter storms.

“We’re only just now discovering how important ocean warming is to our daily lives, to our daily weather,” she said.

Could the Hot Pacific Blob Become Permanent

How Arctic Sea Ice Loss Could Make the Hot Pacific Blob Permanent 

Robertscribbler,

21 June, 2018

From the North Pacific to the tropics, loss of sea ice will result in a vastly heated Pacific Ocean in which events like the recent Hot Blob become far more common. Those were the conclusions of a new model study conducted by Wang, Deser, Sun and Tomas and recently published in Geophysical Research Letters.

(Understanding how sea ice loss in the Arctic can result in large-scale Pacific warming.)

An ocean heating event called the Blob resulted in mass loss of sea life during the period of 2013-2014. It was associated with a towering high pressure ridge in which the upper level winds ran far to the north and into the Arctic. Beneath the ridge, temperatures both at the land and ocean surface grew to be much warmer than normal.

Though viewed as a fluke by some, many began to draw connections between the powerful ridge feature, the related Pacific warming, and sea ice loss in the Arctic. Now, a new scientific study using climate models has produced some rather telling findings. First, the study found that Arctic sea ice loss results in large scale Pacific Ocean warming within just 10-20 years of widespread Arctic Ocean ice reductions. 

Second, the study models indicated that warming occurred first and strongest in the North Pacific, but then rapidly translated toward the Equator.

(Sea surface temperatures across the North Pacific were much warmer than normal during the hot Blob event of 2013-2014. A new model study finds that sea ice loss will make such extreme events common.)

The reason for this change in planetary and Pacific Ocean energy balance is scientifically described as a teleconnection. In very basic terms, loss of sea ice at the Arctic Ocean surface produces changes in local wind patterns that ripple through the global atmosphere. After a rather short period of time, wind patterns in the upper levels of the atmosphere and at the surface in the Pacific Ocean become involved.

Winds are often the vehicle by which energy is transferred throughout the atmosphere and at the surface. So a change in winds, from the top of the atmosphere to the bottom, can swiftly translate to a change in surface temperatures.

(A new model study shows radical changes in Pacific sea surface temperatures in response to Arctic Ocean sea ice loss.)

Looking at the study, it appears more likely now that the Northern Pacific Hot Blob of 2013-2014 was not a fluke, but instead an early knock-on effect of Arctic sea ice loss. A kind of event that will tend to become commonplace as the Arctic Ocean ice continues to melt. And that eventually, sooner rather than later, the heat build-up in the North Pacific will translate south to the Equator. First warming the Eastern Pacific in a more persistent El Nino type pattern and then spreading west (see image above).

As with the Blob, everything from the health of sea life to the intensity of extreme weather would be substantially impacted by such large scale changes. In other words, it looks like large scale losses of Arctic sea ice are enough to affect a broad and disruptive change in the global climate regime.

Models used to estimate past ocean temperatures might be based on a flawed assumption

Scientists Just Found a Serious Flaw in Ocean Temperature Calculations

Oh no.

Science Alert,

17 October, 2017

Models used to estimate past ocean temperatures might be based on a flawed assumption, according to new research.

If true, it would mean our ancient seas were far cooler than previously calculated, and our planet's current warming trend is even more extraordinary than we thought.

A team of scientists from some of Europe's leading research institutes has taken a critical look at a chemical process that has served as a proxy for determining the temperatures of oceans millions of years in the past.

Even the most solid of scientific models rests on fairly well-reasoned assumptions.

In this case, the method for calculating temperature was based on the thought that temperatures were preserved perfectly inside tiny marine organisms called foraminifera.

Specifically, the exact ratio of oxygen-18 to oxygen-16 in the calcite of the organisms' exoskeletons varies with the isotope concentrations in the environment – a factor that was determined by things like acidity and salinity – and the water's temperature.

So if we determine the differences in the oxygen isotopes in fossils, we have a record of the temperatures as they were when they lived a little over 100 million years ago.

This tells us the temperature of the deeper parts of the ocean at the tropics were about 15 degrees Celsius warmer than today.

Yet it turns out things might not be quite so straightforward.

"What appeared to be perfectly preserved fossils are in fact not," says Sylvain Bernard, a mineralogist from the French National Center for Scientific Research.

Evidence now suggests the ratio of oxygen-18 to oxygen-16 in the buried marine life might not be quite as stable as thought.

To test how the chemistry of the calcite in the foraminifera's shells might continue to change over time, the researchers placed a sample of the organisms in artificial sea water that contained just isotopes of oxygen-18.

They then cranked the temperature to simulate the heat generated by being buried beneath a pile of sediment and used a device called a nanoscale secondary ion mass spectrometer (or NanoSIMS) to analyse changes in the calcite's oxygen ratios.

Sure enough, the equilibrium shifted, changing the ratios.

"This means that the paleotemperature estimates made up to now are incorrect," says Bernard.

Taken at face value, it implies the waters probably weren't all that much warmer than today. The discovery also helps resolve a paradox that has hinted at an inconsistency in the most favoured models.

Using the oxygen isotope method, ocean temperatures in the tropics during the warm Cretaceous period weren't all that different to the surface temperatures at the poles.

Unfortunately other models on climate and ocean currents don't gel with this shallow gradient, hinting at a problem

In addition, analysing magnesium isotopes in the foraminifera fossils instead of oxygen suggests the sea surface temperatures at higher latitudes were also colder than estimated.

For all of the changes our planet has experienced over the past 100 million years, our oceans have remained pretty stable as far as temperature goes. Cast in that light, today's rapid global warming trend is even more dramatic than we'd thought.

The next step for researchers is to go back to the drawing board on existing data and see exactly what difference the changes make to historical records.

"To revisit the ocean's paleotemperatures now, we need to carefully quantify this re-equilibration, which has been overlooked for too long," says geochemist Anders Meibom from the Swiss Federal Institute of Technology in Lausanne.

"For that, we have to work on other types of marine organisms so that we clearly understand what took place in the sediment over geological time."

We truly are living in an extraordinary period of our planet's history.

This research was published in Nature Communications.

The Great Barrier Reef cannot be saved

Great Barrier Reef can no longer be saved, Australian experts concede

'In our lifetime and on our watch, substantial areas of the Great Barrier Reef and the surrounding ecosystems are experiencing major long-term damage'

the Independent,

28 May, 2017

The Great Barrier Reef – a canary in the coal mine for global warming – can no longer be saved in its present form partly because of the “extraordinary rapidity” of climate change, experts have conceded.

Instead, action should be taken to maintain the World Heritage Site's 'ecological function' as its ecological health declines, they reportedly recommended.

Like coral across the world, the reef has been severely damaged by the warming of the oceans with up to 95 per cent of areas surveyed in 2016 found to have been bleached.

Bleaching is not always fatal but a study last year found the “largest die-off of corals ever recorded” with about 67 per cent of shallow water coral found dead in a survey of a 700km stretch.

Now experts on a committee set up by the Australian government to improve the health of the reef have revealed that they believe the lesser target of maintaining its “ecological function” is more realistic.

In a recent communique, the expert panel said they were “united in their concern about the seriousness of the impacts facing the Reef and concluded that coral bleaching since early 2016 has changed the Reef fundamentally”. 

 “There is great concern about the future of the Reef, and the communities and businesses that depend on it, but hope still remains for maintaining ecological function over the coming decades,” it said.

“Members agreed that, in our lifetime and on our watch, substantial areas of the Great Barrier Reef and the surrounding ecosystems are experiencing major long-term damage which may be irreversible unless action is taken now. 

“The planet has changed in a way that science informs us is unprecedented in human history. While that in itself may be cause for action, the extraordinary rapidity of the change we now observe makes action even more urgent.”

It recommended that reducing greenhouse gas emissions “must be central to the response”. 

“This needs to be coupled with increased efforts to improve the resilience of the coral and other ecosystems that form the Great Barrier Reef. The focus of efforts should be on managing the Reef to maintain the benefits that the Reef provides,” it added.

While the committee's communique did not expressly give up hope that the reef could be saved in its current form, the Guardianreported that two experts on the committee, speaking anonymously, revealed they had recommended introducing the goal of maintaining "ecological function" at a recent meeting.

And the Great Barrier Reef Marine Park Authority explained what that would mean. 

“The concept of ‘maintaining ecological function’ refers to the balance of ecological processes necessary for the reef ecosystem as a whole to persist, but perhaps in a different form, noting the composition and structure may differ from what is currently seen today,” the authority said.

Professor Ove Hoegh-Guldberg, who sits on the expert panel, told the newspaper they were trying to manage reefs in a “rapidly changing world”.

“So managing to restore the reefs of the past – the way they were prior to the big insults of the 80s, 90s and 2000s ... maybe we need to be looking at this in a different sense,” he said.

“What are the key ecological functions? Essentially, what roles do they play that are important to humans?”

The expert committee's views could lead to the reef beingdeclared a World Heritage Site "in danger", a finding that the Australian government has resisted

The collapsing Gulf Stream

I have been aware of this possibility since 2003

Ocean current sends out chilling warning

New research forecasts much colder weather in northern Europe if rising CO2 emissions continue to impact on the Atlantic ocean current.

 Network,

8 January, 2017

LONDON, 8 January, 2017 – Here is the long-term weather forecast for the North Atlantic, in a world in which carbon dioxide concentrations in the atmosphere double: a powerful ocean current called the Atlantic Meridional Overturning Circulation (AMOC) will continue to weaken, and then collapse.

This is the ocean current that takes tropic heat northward, and then grows cold, dives to the ocean floor, and runs southward. And it is the current that delivers the heat that, for example, keeps the British Isles 5°C warmer than their latitude might dictate.

Carbon dioxide absorbs heat reflected from the rocks. And the more carbon dioxide in the atmosphere, the warmer the planet will become.

For two centuries, humans have been burning fossil fuels and putting ancient carbon back into the atmosphere. The average planetary temperatures, so far, have climbed about 1°C.

If CO2 levels double, temperatures will climb a lot higher. For the first 300 years after the carbon dioxide doubling, nothing much will happen. But then there will be a sweeping drop in temperatures over the north Atlantic.

New climate models

The rain belt will migrate south over the tropical ocean, the sea ice will expand to cover the waters to the south of Greenland, and around Iceland and Norway, and Britain and parts of northern Europe will become much colder.

That is what a new climate model predicts. Scientists from the Scripps Institution of Oceanography, US, and colleagues report in Science Advances journal that the outcome depends on just how computer simulations are framed.

At the moment, the standard climate models predict that the paradox of a colder Europe in a warmer world won’t happen. But the new analysis, the authors say, corrects for biases that predict only moderate changes in what climate scientists call the “Ocean Conveyor”.

“Prominent cooling over the northern
North Atlantic and neighbouring areas . . .
has enormous implications for regional
and global climate change”

And their corrected version suggests a much more apocalyptic outcome: a slow-burning horror story of fire and ice.

“In current models, AMOC is systematically biased to be in a stable regime,” says the study’s lead author, Wei Liu, a Yale University postdoctoral associate who began his research as a graduate student at the University of Wisconsin-Madison and continued it at Scripps Institution of Oceanography.

“A bias-corrected model predicts a future AMOC collapse with prominent cooling over the northern North Atlantic and neighbouring areas. This has enormous implications for regional and global climate change.”

This is the scenario painted luridly in the 2004 disaster movie, The Day After Tomorrow. Although the film is science fiction, scientists have been worrying about the stability of the Ocean Conveyor for at least a decade. The Arctic is warming rapidly, and the consequences for the continents to the south may not be comfortable.

Ocean current weakening

Researchers have offered tentative evidence that the Atlantic ocean current could be weakening. There have been warnings in two studies that Europe, in particular, could see a drop in temperatures.

Right now, outcomes remain speculative, and there are many more factors to be considered. Even in the worst case scenario, the Atlantic ocean current shutdown will not happen for several hundred years.

What the new research really says is that what the computer models predict depends very much on how the data are presented.

Or, in the words of the four authors: “Our results highlight the need to develop dynamical metrics to constrain models and the importance of reducing model biases in long-term climate projections.” – Climate News Network