Category Archives: Climate Change

Satellite observations show sea levels rising, and climate change is accelerating it

Sea level rise is happening now, and the rate at which it is rising is increasing every year, according to a recently released study in the Proceedings of the National Academy of Sciences.

Researchers, led by University of Colorado-Boulder professor of aerospace engineering sciences Steve Nerem, used satellite data dating to 1993 to observe the levels of the world’s oceans. Using satellite data rather than tide-gauge data that is normally used to measure sea levels allows for more precise estimates of global sea level, since it provides measurements of the open ocean.

The team observed a total rise in the ocean of 7 centimeters (2.8 inches) in 25 years of data, which aligns with the generally accepted current rate of sea level rise of about 3 millimeters (0.1 inches) per year. But that rate is not constant. Continuous emissions of greenhouse gases are warming the Earth’s atmosphere and oceans and melting its ice, causing the rate of sea level rise to increase.
Changes in sea level observed between 1992 and 2014. Orange/red colors represent higher sea levels, while blue colors show where sea levels are lower.
“This acceleration, driven mainly by accelerated melting in Greenland and Antarctica, has the potential to double the total sea level rise by 2100 as compared to projections that assume a constant rate, to more than 60 centimeters instead of about 30,” said Nerem, who is also a fellow with the Cooperative Institute for Research in Environmental Science.
That projection agrees perfectly with climate models used in the latest International Panel on Climate Change report, which show sea level rise to be between 52 and 98 centimeters by 2100 for a “business as usual” scenario  (in which greenhouse emissions continue without reduction).
Therefore, scientists now have observed evidence validating climate model projections, as well as providing policy-makers with a “data-driven assessment of sea level change that does not depend on the climate models,” Nerem said.
Sea level rise of 65 centimeters, or roughly 2 feet, would cause significant problems for coastal cities around the world. Extreme water levels, such as high tides and surges from strong storms, would be made exponentially worse.
Consider the record set in Boston Harbor during January’s “bomb cyclone” or the inundation regularly experienced in Miami during the King tides; these are occurring with sea levels that have risen about a foot in the past 100 years.
Now, researchers say we could add another 2 feet by the end of this century.
Nerem provided this chart showing sea level projections to 2100 using the newly calculated acceleration rate.
Nerem and his team took into account natural changes in sea level thanks to cycles such as El Niño/La Niña and even events such as the 1991 eruption of Mount Pinatubo, which altered sea levels worldwide for several years. The result is a “climate-change-driven” acceleration: the amount the sea levels are rising because of the warming caused by manmade global warming.
The researchers used data from other scientific missions such as GRACE, the Gravity Recovery and Climate Experiment, to determine what was causing the rate to accelerate.
NASA’s GRACE mission used satellites to measure changes in ice mass. This image shows areas of Antarctica that gained or lost ice between 2002 and 2016.
Currently, over half of the observed rise is the result of “thermal expansion”: As ocean water warms, it expands, and sea levels rise. The rest of the rise is the result of melted ice in Greenland and Antarctica and mountain glaciers flowing into the oceans.
Theirs is a troubling finding when considering the recent rapid ice loss in the ice sheets. “Sixty-five centimeters is probably on the low end for 2100,” Nerem said, “since it assumes the rate and acceleration we have seen over the last 25 years continues for the next 82 years.”
We are already seeing signs of ice sheet instability in Greenland and Antarctica, so if they experience rapid changes, then we would likely see more than 65 centimeters of sea level rise by 2100.”
Penn State climate scientist Michael Mann, who was not involved with the study, said “it confirms what we have long feared: that the sooner-than-expected ice loss from the west Antarctic and Greenland ice sheets is leading to acceleration in sea level rise sooner than was projected.”
Featured image: Greenland’s melting glaciers may someday flood your city.
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Rapid growth in acidity in the Arctic ocean linked to climate change

The Arctic is suffering so many consequences related to climate change, it’s hard to know where to begin anymore. It’s warming more rapidly than almost any other part of the planet; its glaciers are melting and its sea ice is retreating; and its most iconic wildlife, including polar bears and walruses, are suffering.

But that’s not all — a new study, just out Monday in the journal Nature Climate Change, indicates that the Arctic Ocean is also becoming more acidic, another consequence caused by greenhouse gases in the atmosphere. It’s a process that occurs when carbon dioxide dissolves out of the air and into the sea, lowering the water’s pH in the process.

Scientists believe acidification is occurring at varying rates all over the world. But this week’s study gives researchers renewed cause to worry about the Arctic, suggesting that a large — and increasing — swath of the ocean may have reached a level that’s dangerous for some marine organisms.

The new research focuses on the water concentrations of a mineral called aragonite, which is a form of calcium carbonate, a chemical compound that plankton, shellfish and even deep-sea corals use to build their hard outer shells. When ocean water becomes more acidic, chemical reactions occur that impede the formation of calcium carbonate and lower its concentration in the water, which can be a major threat for these marine animals.

These aragonite levels are a “very important parameter” which can be an indicator of how much carbon dioxide is dissolving into the sea, according to Liqi Chen, a scientist with China’s State Oceanic Administration and a co-author on the new study.

By analyzing data collected from the ocean during expeditions between 1994 and 2010, the scientists have found that some parts of the western Arctic Ocean are undersaturated with aragonite — in other words, their concentrations are lower than they could be. And these areas have expanded more than sixfold since the 1990s.

. . . “Models indicate that sea ice will continue to decrease and the prediction is that the Arctic Ocean may be ice-free in the summer by 2030,” they write. If this occurs, their projections suggest that the entire surface of the Arctic Ocean, up to about 30 meters deep, may be undersaturated with aragonite within two decades. And given the rate of expansion they’ve observed since 1994, they suggest that the entire western Arctic Ocean — up to 250 meters deep — could also become undersaturated within a few decades. . .

Featured Image: Ice floes in Baffin Bay above the Arctic Circle, seen from the Canadian Coast Guard icebreaker Louis S. St-Laurent, in July 2008. (Jonathan Hayward/Canadian Press via AP)

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Scientists just measured a rapid growth in acidity in the Arctic ocean, linked to climate change

February 27, 2017

Global Warming Clobbers Ocean Life

The waters of the Pacific off the California coast are transparently clear. Problem is: Clear water is a sign that the ocean is turning into desert (Source: National Oceanic and Atmospheric Administration, NOAA).

From Alaska to Central America, and beyond, sea life has been devastated over the past three years like never before. . . scientists refer to the lethal ocean warming over the past few years as “the Warm Blob.”

After all, global warming hits the ocean much, much harder than land. Up to 90% of anthropogenic (human-caused) global warming is absorbed by the ocean, which is fortuitous for humans.

“Upper ocean heat content has increased significantly over the past two decades” (Source: Climate Change: Ocean Heat Content, NOAA, Climate.gov, July 14, 2015). More than 3,000 Argo floats strategically positioned worldwide measure ocean temps every 10 days.

Scientists classify the Warm Blob phenomenon as “multi-year ocean heat waves,” with temperatures 7° F above normal and up to 10°F above normal in extreme cases. How would humans handle temperatures, on average, 7° to 10°F above normal? There’d be mass migrations from Florida to Alaska, for sure. As it happens, sea animals do not do well. They die in unbelievably massive numbers; all across the ocean… the animal die-offs are unprecedented. Scientists are stunned!

After years of horrendous worldwide sea animal die-offs, 2016 was a banner year. Is this out of the ordinary? Sadly, the answer is: Yes.

The numbers are simply staggering, not just in the Pacific, but around the world, e.g., the following is but a partial list during only one month (December 2016): Tens of thousands of dead starfish beached in Netherlands; 6,000 dead fish in Maryland waterway; 10 tons of dead fish in Brazilian river; tens of thousands of dead fish wash up on Cornwall, England beach; schools of dead herring in Nova Scotia; 100 tons of fish suddenly dead in Indonesia; massive fish deaths ‘state of calamity’ in Philippines; thousands of dead crayfish float down river in New Zealand; masses of dead starfish, crabs, and fish wash ashore in Nova Scotia, and there are more and more….

In fact, entire articles are written about specific areas of massive die offs, for example: “Why Are Chilean Beaches Covered With Dead Animals?” Smithsonian.com, May 4, 2016. Chilean health officials had to resort to heavy machinery to remove 10,000 dead rotting squid from coastlines earlier in the 2016 year. Over 300 whale carcasses hit the beaches and 8,000 tons of sardines and 12% of the annual salmon catch… all found dead on beaches, to name only a few! You’ve gotta wonder why?

According to Nate Mantua, research scientist at the National Oceanic and Atmospheric Administration’s Southwest Fisheries Science Center in Santa Cruz, California: “One of the things that is clear is there’s a lot of variation from year to year along the Pacific Coast, and some of that is tied into natural patterns, like El Niño,’ Mantua said. ‘But what we saw in 2014, ‘15 and the first part of ‘16 was warmer than anything we’ve seen in our historical records, going back about 100 years” (Mary Callahan, Year in Review: Ocean Changes Upend North Coast Fisheries, The Press Democrat, Dec. 25, 2016).

climate-change-photo-nasa-kathryn-hansen2

 Photo: NASA/Kathryn Hansen 

. . . Morosely, too-warm ocean water serves as breeding ground for the infamous deadly “red tide,” a bloom of single-celled organism that thrives in warmer waters, producing a neurotoxin called domoic acid, resulting in enormous numbers of sea lion fatalities and massive destruction of Dungeness crab fisheries and all kinds of other trouble.

Too-warm water also contributes to the collapse of bull kelp forests, which are the ocean’s equivalent of the tropical rain forest; meanwhile, purple urchins thrive and multiply in explosive fashion in the poisonous environment, devouring remaining plant life. Thereby, out-competing hapless red abalone, the shellfish that people love.

Collapsing food chains are evident up and down the Pacific Coast earmarked by large die offs of Cassin Auklets, a tiny seabird, as well as massive numbers of Common Murres. The sea lions and fur seals suffer from starvation and domoic acid poisoning. In early 2013 scientists declared the sea lion die-off an “unusual mortality event.”

Nursing sea lion mothers are unable to find enough forage like sardines and anchovies.

. . . Bottom line, the ecosystem is under fierce attack, and it is real, very real indeed with too much global warming, too much ag runoff, too much heavy-duty massive overfishing, likely too much nuclear radiation, and deadly acidification caused by excessive CO2 concentrations (already damaging pteropods at the base of the marine food chain) as the ocean absorbs anthropogenic CO2 emissions from fossil fuels, similar to the upper atmospheric conundrum where 400+ ppm of CO2 (anything over 350 ppm leads to serious planetary trouble over time) is already heating up the planet as the ocean absorbs 90% of that heat.

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GLOBAL WARMING CLOBBERS OCEAN LIFE

by ROBERT HUNZIKER

JANUARY 16, 2017

http://www.counterpunch.org/2017/01/16/global-warming-clobbers-ocean-life/

Featured image photo credit: NASA/Kathryn Hansen

Ocean acidification study offers warnings for marine life, habitats

Sea grass beds, like these off the coast of British Columbia, Canada, might buffer the impacts of ocean acidification.Christopher Harley,University of British Columbia

Acidification of the world’s oceans could drive a cascading loss of biodiversity in some marine habitats, according to research published Nov. 21 in Nature Climate Change.

The work by biodiversity researchers from the University of British Columbia, the University of Washington and colleagues in the U.S., Europe, Australia, Japan and China, combines dozens of existing studies to paint a more nuanced picture of the impact of ocean acidification.

While most research in the field focuses on the impact of ocean acidification on individual species, the new work predicts how acidification will affect the living habitats such as corals, seagrasses and kelp forests that form the homes of other ocean species.

“Not too surprisingly, species diversity in calcium carbonate-based habitats like coral reefs and mussel beds were projected to decline with increased ocean acidification,” said lead author Jennifer Sunday, a UBC zoologist and biodiversity researcher. Species that use calcium carbonate to build their shells and skeletons, like mussels and corals, are expected to be particularly vulnerable to acidification.

“The more complex responses are those of seagrass beds that are vital to many fisheries species. These showed the potential to increase the number of species they can support, but the real-world evidence so far shows that they’re not reaching this potential. This highlights a need to focus not only on individual species, but on how the supportive habitat that sets nature’s stage responds and interacts to climate change.”

. . .The researchers focused their study on the impact of ocean acidification on coral reefs, mussel beds, kelp forests and seagrass meadows that form the homes of thousands of marine species. They used observations of altered habitats around the world to project how changes in these habitats brought on by ocean acidification will impact the number of species that each habitat can support. . .

acidification-coral-ecosystems-like-these-pictured-off-the-coast-of-mexico-will-be-hit-hard-as-the-oceans-become-more-acidic-christopher-harleyuniversity-of-british-columbia

Coral ecosystems, like these pictured off the coast of Mexico, will be hit hard as the oceans become more acidic.Christopher Harley, University of British Columbia

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Ocean Acidification study offers warnings for marine life, habitats

November 21, 2016

http://www.washington.edu/news/2016/11/21/ocean-acidification-study-offers-warnings-for-marine-life-habitats/

See UBC news release.

Why Global Warming Hits the Arctic Harder Than Anywhere Else

The melting of the sea ice has consequences on all levels, from local to global. Locally, all the animals that live up there have evolved to live with the sea ice, so its disappearance will have major effects through the entire food web.

For example, there are certain algae that need to live under the ice. Those organisms are an important food source for little shrimplike creatures called amphipods. Those organisms, in turn, are eaten by Arctic cod, which are eaten by seals, which are eaten by polar bears. There are projections that the polar bear population is going to crash as the ice keeps melting. Already in the Beaufort Sea, we have seen a 30 percent decline in the polar bear population.

Melting sea ice also sets up a feedback loop. Ice reflects a lot of the sun’s energy back up toward space, while open water absorbs more of that heat. So the less ice and the more water, the more the planet warms. (Read about the astronaut who is using his final days to fight for climate change awareness).

. . . A warming Arctic is going to affect our planet’s systems of ocean currents and wind patterns, which help drive a lot of our weather. Now, there is a giant conveyor belt in which cold water that forms near the edge of sea ice sinks, only to be replaced by warmer water from the south. This process makes the British Isles comfortable to live in, for example, instead of frigid. But this whole conveyor system is in danger of disruption as the poles warm.

As the Arctic warms, it may also impact air currents, such as the jet stream, which drives a lot of weather in North America by blocking or shuttling cold air.

. . . The Arctic is warming two to three times faster than the average for the rest of the planet. It’s ironic, because the carbon emissions that are warming the planet are not produced in the Arctic, yet the Arctic is suffering the most. At the same time, what happens there is going to affect the rest of the planet.

Part of the problem is that at lower latitudes you often have more mixing of air and water, but the Arctic is more isolated at the top of the world. Also, warming of one or two degrees there has a bigger impact than other places because that’s enough to melt a huge amount of ice. That leads to dramatic changes in the landscape and sets up that feedback loop that leads to even more warming.

As the planet warms, species in temperate zones have been migrating northward. But Arctic species have nowhere to go. That’s a problem of living at the top of the world.

. . . A warming Arctic is going to impact the people who live up there. The animals they depend on, such as seals and polar bears, are going to decline, so they are going to have a hard time preserving their hunting traditions.

READ FULL ARTICLE AT: Why Global Warming Hits the Arctic Harder Than Anywhere Else  

Explorer and marine biologist Enric Sala talks with Leonardo DeCaprio about his new documentary, Before the Flood.

By Brian Clark Howard

October 25, 2016

http://news.nationalgeographic.com/2016/10/enric-sala-global-warming-climate-change-arctic-btf/

Photo: Ice floes in Baffin Bay above the Arctic Circle, The Canadian Press, Jonathan Hayward)(Credit: AP)

 

The Great Barrier Reef: a catastrophe laid bare

Since 1982, just after mass bleachings were seen for the first time, the data shows that the average proportion of the Great Barrier Reef exposed to temperatures where bleaching or death is likely has increased from about 11% a year to about 27% a year.

Eakin says looking at that data revealed a clear trend that hadn’t been quantified before. “In seeing that what it immediately showed was that there was a real background pattern of increasing levels of thermal stress.”

Combined with other stressors hitting the reef, this is having a devastating impact. Over that period, half the coral cover on the Great Barrier Reef has been lost – and that’s before the mass bleaching this year is taken into account.

That data has limitations – it’s not direct bleaching, but stress inferred from temperature readings. And it lumps extreme levels of stress – like what is being seen around Lizard Island now – with anything that is expected to cause mortality.

Despite that, it reveals the way global warming is leading to more regular bleaching and mortality.

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The Great Barrier Reef: A Catastrophe Laid Bare

By Michael Slezak

7 June 2016

https://www.theguardian.com/environment/2016/jun/07/the-great-barrier-reef-a-catastrophe-laid-bare

Extreme Arctic sea ice melt forces thousands of walruses ashore in Alaska

Aerial photograph of thousands of pacific walrus coming ashore near point lay on the north west arctic coast of Alaska Photo: Gary Braasch/Corbis

Survival of walruses threatened as they wash ashore on a remote barrier island.

The extreme loss of Arctic sea ice due to climate change is forcing thousands of walruses to crowd ashore on a remote barrier island off Alaska, and threatening their survival.

. . . Such landings, forced by the absence of sea ice on which to rest and feed, put the animals at risk of stampede in the limited space of the barrier island.

The animals are easily spooked by aircraft or onlookers, government scientists warned. Trampling deaths are one of the biggest natural risks.

Sea ice cover in the winter months fell to a new low this year because of climate change and abnormal weather patterns.

Some scientists believe the Arctic could be entirely ice-free in the summer months by the 2030s – with profound effects for local indigenous communities that rely on the ice, as well as wildlife that depend on extreme conditions.

Since 2000, the forced migration of walruses and their young to barrier islands such as Point Lay – known as a “haul out” – has become an increasingly regular occurrence, according to US government scientists.

. . . Last year, as many as 40,000 animals, mainly females and their young, were forced ashore. It was the biggest known haul-out of its kind in the US Arctic, according to government scientists. The Federal Aviation Authority re-routed flights and bush pilots were told to keep their distance to avoid a stampede.

Agency scientists said about 60 young walruses were killed because of crowding and stampedes.

                               climate-change-an-estimated-35000-walruses-are-pictured-are-pictured-hauled-out-on-a-beach-near-the-village-of-point-lay-alaska-700-miles-north-west-of-anchorage-in-this-september-2014-photogra

An estimated 35,000 walruses, hauled out on a beach near the village of Point Lay. Alaska, 700 miles north west of anchorage September, 2014.

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Extreme Arctic sea ice melt forces thousands of walruses ashore in Alaska

August 27, 2015

https://www.theguardian.com/environment/2015/aug/27/walruses-alaska-arctic-sea-ice-melt

 Featured image: Aerial photograph of thousands of pacific walrus coming ashore near point lay on the north west arctic coast of Alaska, Photo: Gary Braasch/Corbis

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