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...
Choices made now are critical for the future of our ocean and cryosphere

Choices made now are critical for the future of our ocean and cryosphere

SOURCE: IPCC DATE: September 25, 2019 SNIP: The latest Intergovernmental Panel on Climate Change (IPCC) Special Report highlights the urgency of prioritizing timely, ambitious and coordinated action to address unprecedented and enduring changes in the ocean and cryosphere. Global warming has already reached 1°C above the pre-industrial level, due to past and current greenhouse gas emissions. There is overwhelming evidence that this is resulting in profound consequences for ecosystems and people. The ocean is warmer, more acidic and less productive. Melting glaciers and ice sheets are causing sea level rise, and coastal extreme events are becoming more severe. People in mountain regions are increasingly exposed to hazards and changes in water availability, the report said. Glaciers, snow, ice and permafrost are declining and will continue to do so. This is projected to increase hazards for people, for example through landslides, avalanches, rockfalls and floods. Smaller glaciers found for example in Europe, eastern Africa, the tropical Andes and Indonesia are projected to lose more than 80% of their current ice mass by 2100 under high emission scenarios. Glaciers and ice sheets in polar and mountain regions are losing mass, contributing to an increasing rate of sea level rise, together with expansion of the warmer ocean. While sea level has risen globally by around 15 cm during the 20th century, it is currently rising more than twice as fast – 3.6 mm per year – and accelerating, the report showed. Sea level will continue to rise for centuries. It could reach around 30-60 cm by 2100 even if greenhouse gas emissions are sharply reduced and global warming is limited to well...
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...
Surprise! Unexpected ocean heat waves are becoming the norm

Surprise! Unexpected ocean heat waves are becoming the norm

SOURCE: The Daily Climate and PNAS DATE: August 6, 2019 SNIP: Ocean heat waves, which can push out fish, plankton and other aquatic life, are happening far more frequently than previously thought, according to a study published today in the Proceedings of the National Academy of Sciences. “Based on historical and lived experience, people expect certain conditions to prevail in the ecosystems they depend upon. Climate change is now introducing strong trends that push conditions beyond historic levels,” the authors wrote. Led by the Gulf of Maine Research Institute, researchers looked at 65 large marine ecosystems around the world over the past 164 years to determine how frequently “surprising” ocean temperatures occur, with surprising defined as an event expected to occur about two times in 100 years, lead author and chief scientific officer at the Gulf of Maine Research Institute Andrew Pershing told EHN via email. Pershing and colleagues reported that over the past seven years, the planet averaged 12 ecosystems each year experiencing the kind of unusually warm temperatures that someone in the given region would expect to see only a couple times in a century. In 2016 alone there were 23 such events. “Across the 65 ecosystems we examined, we expected about six or seven of them would experience these ‘surprises’ each year,” Pershing said in a statement. The results are in line with what scientists continue to warn: oceans are the Earth’s largest heat collector. According to the National Oceanic and Atmospheric Administration, more than 90 percent of Earth’s warming over the past 50 years has happened in the...
Heatwave cooks mussels in their shells on California shore

Heatwave cooks mussels in their shells on California shore

SOURCE: The Guardian DATE: June 29, 2019 SNIP: In all her years working at Bodega Bay, the marine reserve research coordinator Jackie Sones had never seen anything like it: scores of dead mussels on the rocks, their shells gaping and scorched, their meats thoroughly cooked. A record-breaking June heatwave apparently caused the largest die-off of mussels in at least 15 years at Bodega Head, a small headland on the northern California bay. And Sones received reports from other researchers of similar mass mussel deaths at various beaches across roughly 140 miles (225km) of coastline. While the people who flocked to the Pacific to enjoy a rare 80F (27C) beach day soaked up the sun, so did the mussel beds—where the rock-bound mollusks could have been experiencing temperatures above 100F at low tide, literally roasting in their...