Rising Seas Aren’t Even the Scariest Part of Climate Change in the Oceans

Rising Seas Aren’t Even the Scariest Part of Climate Change in the Oceans

SOURCE: Mother Jones DATE: September 25, 2019 SNIP: Climate change has already taken an irreversible toll on our oceans and frozen places, warns a major new report from the United Nations’ Intergovernmental Panel on Climate Change. Much of the carbon pollution we’ve pumped into the air has gone directly into the world’s seas: They have absorbed 90 percent of the excess heat from the atmosphere, warming without pause for the past 50 years. Because oceans are so unfathomably big and complex—covering two-thirds of Earth’s surface—that warming has consequences for the entire planet. The IPCC Special Report on Ocean and Cryosphere In A Changing Climate is a collaboration among 130 scientists around the world who have assembled data from more than 7,000 papers. The new report manages to paint an even bleaker picture, showing that the oceans have been expanding, acidifying, and losing oxygen at an accelerated rate. One major takeaway from the report: The seas are rising twice as fast as twentieth century averages. The ocean is also heating up twice as fast, absorbing more carbon and acidifying. “The rate of climate change has actually gone up,” lead author of the report’s chapter on oceans, Nate Bindoff of the University of Tasmania, said in a call with reporters. This acceleration of warming and acidification means a cascade of impacts on weather and marine life, such as coral reefs, some of which we still don’t fully understand. The IPCC looks at a range of possible climate-change scenarios, from unabated pollution to dramatic reforms in the next decade. Right now, though, the world is on the most dangerous warming path. Our...
Greenland’s Growing “Ice Slabs” Intensify Meltwater Runoff into Ocean

Greenland’s Growing “Ice Slabs” Intensify Meltwater Runoff into Ocean

SOURCE: CIRES DATE: September 18, 2019 SNIP: Thick, impenetrable ice slabs are expanding rapidly on the interior of Greenland’s ice sheet, where the ice is normally porous and able to reabsorb meltwater. These slabs are instead sending meltwater spilling into the ocean, according to a new CIRES-led assessment, threatening to increase the country’s contribution to sea level rise by as much as 2.9 inches by 2100. Although runoff from ice slabs has added less than a millimeter to global sea levels so far, this contribution will grow substantially as ice slabs continue to expand in a warming climate, said Mike MacFerrin, a CIRES and University of Colorado Boulder researcher who led the new study, published today in Nature. “Even under moderate climate projections, ice slabs could double the size of the runoff zone by 2100,” MacFerrin said. “Under higher emissions scenarios, the runoff zone nearly triples in size.” “As the climate continues to warm, these ice slabs will continue to grow and enhance other meltwater feedbacks,” said Mahsa Moussavi, NSIDC researcher and a coauthor on the paper. “It’s a snowball effect: more melting creates more ice slabs, which create more melting, which, creates again more ice slabs.” This process fundamentally alters the ice sheet’s present and future hydrology. Arctic feedbacks like this are critical to understand because they show just how much, and how quickly, a warming climate can change Earth’s most vulnerable...
Rising sea levels and catastrophic storm surges could displace 280m people, UN warns

Rising sea levels and catastrophic storm surges could displace 280m people, UN warns

SOURCE: Independent and Al Jazeera DATE: August 29, 2019 SNIP: The damage caused by catastrophic “superstorms” combined with rising sea levels could increase by a hundred-fold or more, displacing hundreds of millions of people from coastlines around the world unless more is done to limit greenhouse gas emissions, according to a draft report by the United Nations. According to French news agency AFP, which said it had obtained a copy of the report, the document outlines a grim scenario in which the warming oceans are “poised to unleash misery on a global scale”, with declining fish stocks, the melting of sea ice and glaciers, and increasing levels of human displacement. Unless there are serious cuts to man-made greenhouse gas emissions, at least 30 per cent of the northern hemisphere’s surface permafrost could melt within just 80 years, the report warns. This melt would unleash billions of tonnes of carbon stored in what are currently permafrost areas, which will accelerate rates of global warming even more. The upshot would be warming seas and rising coastlines, which could immediately threaten 280 million people, the document says. Last week a report from the [UK] Science and Technology Select Committee said efforts to reduce emissions have been undermined by “unacceptable” cutbacks and delays, meaning we face “dire consequences”. And on Thursday, the [UK] government’s chief environment scientist said the UK cannot hit its net zero emissions goal while ministers are fixed on economic growth as measured by GDP. The US – the second biggest contributor of CO2 – is exiting the Paris agreement on climate change, under Donald Trump’s leadership. China – the...
Scientists Have Been Underestimating the Pace of Climate Change

Scientists Have Been Underestimating the Pace of Climate Change

SOURCE: Scientific American DATE: August 19, 2019 SNIP: Recently, the U.K. Met Office announced a revision to the Hadley Center historical analysis of sea surface temperatures (SST), suggesting that the oceans have warmed about 0.1 degree Celsius more than previously thought. The need for revision arises from the long-recognized problem that in the past sea surface temperatures were measured using a variety of error-prone methods such as using open buckets, lamb’s wool–wrapped thermometers, and canvas bags. It was not until the 1990s that oceanographers developed a network of consistent and reliable measurement buoys. Then, to develop a consistent picture of long-term trends, techniques had to be developed to compensate for the errors in the older measurements and reconcile them with the newer ones. The Hadley Centre has led this effort, and the new data set—dubbed HadSST4—is a welcome advance in our understanding of global climate change. But that’s where the good news ends. Because the oceans cover three fifths of the globe, this correction implies that previous estimates of overall global warming have been too low. Moreover it was reported recently that in the one place where it was carefully measured, the underwater melting that is driving disintegration of ice sheets and glaciers is occurring far faster than predicted by theory—–as much as two orders of magnitude faster—–throwing current model projections of sea level rise further in doubt. These recent updates, suggesting that climate change and its impacts are emerging faster than scientists previously thought, are consistent with observations that we and other colleagues have made identifying a pattern in assessments of climate research of underestimation of certain key...
Solomon Islands disappearing beneath rising sea at ‘unprecedented’ rate

Solomon Islands disappearing beneath rising sea at ‘unprecedented’ rate

SOURCE: 60 Minutes Digital and 9News DATE: May 12, 2019 SNIP: With crystal clear blue waters and white sandy beaches, the Solomon Islands are one of the most stunning and remote parts of the Pacific Ocean. But despite the archipelago’s isolation, it’s no stranger to the unforgiving impacts of climate change: the island paradise is drowning. In the past 20 years, sea levels in the Solomon Islands have risen over 15 centimetres. It doesn’t sound like much, but it’s led to many islands losing critical land mass. Others have disappeared completely. Sceptics say the vanishing islands occur as a result of natural erosion, but Bartlett reports that’s not the case. The remnants of 300-year-old trees which once stood tall, but are now all but drowning, prove the point. Renowned marine ecologist Dr Simon Albert agrees. He’s been studying the effects of climate change and sea level rises in the Solomon Islands for years and has seen the devastating impact of climate change on the small nation. “It’s just mind-blowing really,” he says. “These are permanent islands that have been on these reef platforms for at least the last few hundred years.” “The rates of change we’ve seen over the last 20 years are unprecedented in that...