Ocean Heat Waves Are Directly Linked to Climate Change

Ocean Heat Waves Are Directly Linked to Climate Change

SOURCE: New York Times and Science DATE: September 24, 2020 SNIP: Six years ago, a huge part of the Pacific Ocean near North America quickly warmed, reaching temperatures more than 5 degrees Fahrenheit above normal. Nicknamed “the blob,” it persisted for two years, with devastating impacts on marine life, including sea lions and salmon. The blob was a marine heat wave, the oceanic equivalent of a deadly summer atmospheric one. It was far from a solitary event: Tens of thousands have occurred in the past four decades, although most are far smaller and last for days rather than years. The largest and longest ones have occurred with increasing frequency over time. On Thursday, scientists revealed the culprit. Climate change, they said, is making severe marine heat waves much more likely. The study, published in the journal Science, looked at the blob and six other large events around the world, including one in the Northwest Atlantic in 2012. Human-caused global warming made these events at least 20 times more likely, the researchers found. “Some of these couldn’t even have occurred without climate change,” said Charlotte Laufkötter, a marine scientist at the University of Bern in Switzerland and the lead author of the study. In a world with no human-caused warming, a large marine heat wave would have had about a one-tenth of 1 percent chance of occurring in any given year — what is called a thousand-year event. But with the current rate of global warming, an ocean heat wave like that could soon have as much as a 10 percent chance of occurring, the study found. Dr. Laufkötter said...
Huge ‘hot blob’ in Pacific Ocean killed nearly a million seabirds

Huge ‘hot blob’ in Pacific Ocean killed nearly a million seabirds

SOURCE: The Guardian DATE: January 16, 2020 SNIP: A million seabirds died in less than a year as a result of a giant “blob” of hot ocean water off the coast of New Zealand, according to new research. A study released by the University of Washington found the birds, called the common murre, probably died of starvation between the summer of 2015 and the spring of 2016. Most dead seabirds never wash ashore, so while 62,000 dead or dying murres were found along the coasts of Alaska, Washington, Oregon and California, researchers estimate the total number is closer to 1 million. Alaska saw the most birds wash up. In Prince William Sound in southern Alaska, more than 4,500 bird carcasses were found every kilometer, or 0.62 miles. The blob stems from a years-long severe marine heatwave, believed to be caused by an anticyclone weather system that first appeared in 2013. A weather phenomenon known as El Niño accelerated the warming temperatures beginning in 2015 and, by 2016, the rising heat resulted in water temperatures nearly 11F (6C) above average. Anticyclones form when a mass of air cools, contracts and becomes more dense, increasing the weight of the atmosphere and the surface air pressure. Heat maps at the time showed a massive red blob growing, spanning more than 380,000 sq miles (1 million sq km). That’s nearly 1.5 times the size of Texas or four times larger than New Zealand. The study found that the murres mostly likely starved to death. The seabird must eat half its body weight to survive, but food grew scarce amid intense competition from other...
Ocean temperatures hit record high as rate of heating accelerates

Ocean temperatures hit record high as rate of heating accelerates

SOURCE: The Guardian DATE: January 13, 2020 SNIP: The heat in the world’s oceans reached a new record level in 2019, showing “irrefutable and accelerating” heating of the planet. The world’s oceans are the clearest measure of the climate emergency because they absorb more than 90% of the heat trapped by the greenhouse gases emitted by fossil fuel burning, forest destruction and other human activities. The new analysis shows the past five years are the top five warmest years recorded in the ocean and the past 10 years are also the top 10 years on record. The amount of heat being added to the oceans is equivalent to every person on the planet running 100 microwave ovens all day and all night. Hotter oceans lead to more severe storms and disrupt the water cycle, meaning more floods, droughts and wildfires, as well as an inexorable rise in sea level. Higher temperatures are also harming life in the seas, with the number of marine heatwaves increasing sharply. The most common measure of global heating is the average surface air temperature, as this is where people live. But natural climate phenomena such as El Niño events mean this can be quite variable from year to year. “The oceans are really what tells you how fast the Earth is warming,” said Prof John Abraham at the University of St Thomas, in Minnesota, US, and one of the team behind the new analysis. “Using the oceans, we see a continued, uninterrupted and accelerating warming rate of planet Earth. This is dire news.” “We found that 2019 was not only the warmest year on...
A Marine Heat Wave Intensifies, with Risks for Wildlife, Hurricanes and California Wildfires

A Marine Heat Wave Intensifies, with Risks for Wildlife, Hurricanes and California Wildfires

SOURCE: Inside Climate News DATE: September 18, 2019 SNIP: An intensifying marine heat wave in the northeastern Pacific Ocean has triggered government warnings about harm to salmon and other fisheries along the U.S. West Coast, and it’s raising concerns about hurricane risks to the Hawaiian islands and wildfire risks in California. The current marine heat wave covers a horseshoe-shaped area about the size of Alaska. It extends from the Gulf of Alaska down the coast of Western North America and westward to Hawaii. In the warmest areas, sea surface temperatures have reached about 5.4 degrees Fahrenheit above average. Marine heat waves occur when sea surface temperatures in part of the ocean rise and stay above the expected seasonal temperatures for at least five days in a row. Scientists say these heat waves are forming more frequently, and they suspect that shifts in winds and ocean currents driven by global warming are a big part of the cause. A 2018 study showed that, since 1925, marine heat waves have become 34 percent more frequent and they are lasting longer. The majority of marine heat waves, about 87 percent, can be attributed to human-caused global warming, the authors found. The National Oceanic and Atmospheric Administration is tracking the current marine heat wave and has warned of disruptions to ocean ecosystems and fisheries along the West Coast. Andy Leising, a research scientist at NOAA Fisheries’ Southwest Fisheries Science Center in La Jolla, California, said this year’s warm blob could be as strong as the last and is already one of the most significant marine heat waves on record in the region because...
New marine heat wave resembles killer ‘Blob’ that devastated sea life on West Coast, NOAA says

New marine heat wave resembles killer ‘Blob’ that devastated sea life on West Coast, NOAA says

SOURCE: Seattle Times DATE: September 5, 2019 SNIP: A new marine heat wave has formed off the West Coast that is similar to “The Blob” that devastated sea life and ravaged runs of Pacific salmon. Although the similarities are striking, whether the new system will cause the same havoc is yet to be seen. Like The Blob, which formed in 2014 and peaked in 2015, the new mass of warm water emerged over the course of a few months. A persistent weather pattern has becalmed winds that typically stir up the ocean’s surface to keep it cool. The heat wave is relatively new and right now mostly has affected the upper layers of the ocean. If weather patterns shift, it could break up rapidly, according to the National Oceanic and Atmospheric Administration (NOAA). “It looks bad, but it could also go away pretty quickly,” said Nate Mantua, a research scientist at NOAA’s Southwest Fisheries Science Center in La Jolla, California, in a news release Thursday. The Blob upended the West Coast marine ecosystem, resulting in the deaths of millions of animals, from seabirds to sea lions. Salmon runs cratered, adding to the stress on animals that eat them, including endangered southern resident killer whales. The new expanse of unusually warm water is eerily similar: It has quickly grown in much the same way, in the same area, to almost the same size, stretching from roughly Alaska to California. It is the second-largest marine heat wave in terms of area in the northern Pacific Ocean in the last 40 years, after the earlier Blob. About five years ago, sea temperatures...