Climate Change May Shrink the World’s Fish

Climate Change May Shrink the World’s Fish

SOURCE: National Geographic DATE: Aug 21, 2017 SNIP: Warming temperatures and loss of oxygen in the sea will shrink hundreds of fish species—from tunas and groupers to salmon, thresher sharks, haddock and cod—even more than previously thought, a new study concludes. Because warmer seas speed up their metabolisms, fish, squid and other water-breathing creatures will need to draw more oxyen from the ocean. At the same time, warming seas are already reducing the availability of oxygen in many parts of the sea. A pair of University of British Columbia scientists argue that since the bodies of fish grow faster than their gills, these animals eventually will reach a point where they can’t get enough oxygen to sustain normal growth. “What we found was that the body size of fish decreases by 20 to 30 perent for every 1 degree Celsius increase in water temperature,” says author William Cheung, director of science for the university’s Nippon Foundation—Nereus...
Climate Change Has ‘Permanently’ Changed the Great Barrier Reef

Climate Change Has ‘Permanently’ Changed the Great Barrier Reef

SOURCE: Pacific Standard DATE: March 16, 2017 AUTHOR: Eric Holthaus SNIP: Scientists speculate that the era of never-ending global coral bleaching may have already arrived, decades early. In a new study, published Wednesday as the cover story in the journal Nature, Hughes and his colleagues — the paper includes an astounding 45 co-authors — find that 91 percent of the Great Barrier Reef has bleached at least once during three major bleaching events in 1998, 2002, and 2016. The most recent of these events — triggered in part by a strong El Niño — was so severe that there is no similar analog in the thousands of years of ancient coral cores scientists use to study past climates. The study’s authors further argue that, over the last decade or two, global warming has changed conditions on the Great Barrier Reef so quickly that old conservation methods no longer work. Earlier this month, the authority that oversees the Great Barrier Reef discovered that it has begun bleaching again — just months after its worst bleaching event on record. Quick-growing corals in the Great Barrier Reef require 10 to 15 years to fully recover from a mass-bleaching event, and long-lived species may require many decades. That kind of breathing room is “no longer realistic,” according to Hughes and his colleagues, as long as global temperatures keep...
The world’s oceans are storing up staggering amounts of heat — and it’s even more than we thought

The world’s oceans are storing up staggering amounts of heat — and it’s even more than we thought

SOURCE: The Washington Post DATE: March 10, 2017 SNIP: The world is getting warmer every year, thanks to climate change — but where exactly most of that heat is going may be a surprise. As a stunning early spring blooms across the United States, just weeks after scientists declared 2016 the hottest year on record, it’s easy to forget that all the extra warmth in the air accounts for only a fraction of the heat produced by greenhouse gas emissions. In fact, more than 90 percent of it gets stored in the ocean. And now, scientists think they’ve calculated just how much the ocean has warmed in the past few decades. A new study, out Friday in the journal Science Advances, suggests that since 1960, a staggering 337 zetajoules of energy — that’s 337 followed by 21 zeros — has been added to the ocean in the form of heat. And most of it has occurred since 1980. The new value is a number that significantly exceeds previous estimates, Trenberth [Kevin Trenberth, a senior scientist at the National Center for Atmospheric Research] noted. Compared with ocean warming estimates produced by the Intergovernmental Panel on Climate Change, the new values are about 13 percent...
Earth’s oceans are warming 13% faster than thought, and accelerating

Earth’s oceans are warming 13% faster than thought, and accelerating

SOURCE: The Guardian DATE: March 10, 2017 SNIP: One main outcome of the study is that it shows we are warming about 13% faster than we previously thought. Not only that but the warming has accelerated. The warming rate from 1992 is almost twice as great as the warming rate from 1960. Moreover, it is only since about 1990 that the warming has penetrated to depths below about 700 meters. We know the oceans are much warmer now and they contain the memory of climate change. Higher sea surface temperatures are continually reinforced by the extra heat beneath the ocean surface. The oceans are affecting weather and climate through more intense rains. This process is a major reason why 2016 was the hottest year ever recorded at the Earth’s surface, beating out 2015 which was the previous record. Additionally 2015 was a year with record hurricanes, heat waves, droughts, and wild-fires around the...
Florida Reefs Are Dissolving Much Sooner Than Expected

Florida Reefs Are Dissolving Much Sooner Than Expected

SOURCE: Climate Central DATE: May 3, 2016 AUTHOR: Brian Kahn SNIP: It wasn’t supposed to happen this fast. Some of the reefs around the Florida Keys are dissolving. They may have crossed a tipping point due to increasing ocean acidification, raising the alarm that climate change impacts in the ocean are continuing to happen at a much quicker pace than scientists previously suspected. Rising carbon dioxide levels in the atmosphere are making seas more acidic. That makes it harder for coral to build up their skeletons. Scientists expected that the rising tide of acidic waters would cross a tipping point and start dissolving reefs by mid-century. But some of Florida’s reefs appear to be getting a head start, according to research published in Global Biogeochemical Cycles on Monday. Scientists sampled seven sites across the 300-mile stretch of reefs stretching from Miami south to Key West. The findings show that the northern stretches of the reefs and their limestone bases are already...