Animals & Wildlife Magazine

Yearly Coral Bleaching Will Not End

By Garry Rogers @Garry_Rogers

GR:  Again, let me say: climate change is happening now, and it will get worse.

“Despite La Nina, Ocean surfaces have not cooled enough to end the worst global coral bleaching event on record. What this means is that many reefs, including the Great Barrier Reef, are again under a rising risk of bleaching and mortality for the coming months. This is unheard of. Never before has a mass coral bleaching event lasted for so long or extended through the period of natural variability related ocean surface cooling called La Nina. Perhaps more ominously, the global coral bleaching and die off that began in 2014 may now be a practically permanent ocean feature of the presently destabilized world climate system.

“Cool La Nina is Over. According to NOAA, the periodic cooling of ocean surfaces in the Pacific called La Nina is now over. And since La Nina brings with it a variable related low point of broader Earth surface temperatures, after a few months lag, we can expect the globe to start to warm up again.

Yearly Coral Bleaching Will Not End

The above map shows sea surface temperature anomalies in the Pacific Ocean on February 9 of 2017. Presently SSTs over the entire Pacific range from about -1.5 C below average to +5 C above average. And as you can see, the Ocean is considerably warmer than normal, despite La Nina. Over the next 1-2 years, this is likely the coolest the Pacific will get. In just one decade’s time, under human-forced warming, it will take a very strong La Nina and a strongly negative Pacific Decadal Oscillation to produce similar sea surface temperatures. Image source: Earth Nullschool.

“Problem is, the Earth is still ridiculously warm, despite La Nina. Temperatures, driven inexorably higher by fossil fuel burning, have probably bottomed out at about 1 degrees Celsius hotter than 1880s averages during December, January and February of 2016-2017.

“What this means is that the likely range for annual global temperatures over the next 5 years will be about 1 to 1.3 C above 1880s averages. These readings are so high (the warmest in 115,000 years) and have risen so much, in such a geologically short span of time, that many of the world’s more sensitive species are now being pushed out of their habitats and are undergoing considerable heat-related mortality events.

According to NOAA:

Multiple coral reef regions are already experiencing Alert Level 1 bleaching stress (associated with significant coral bleaching). Alert Level 2 bleaching stress (associated with widespread coral bleaching and significant mortality) is expected in the Northern Cook Islands, Southern Cook Islands, the Samoas, Wallis & Futuna, Northern Tonga, Southern Tonga, the Society Archipelago, and the Austral Islands in the next 1-4 weeks. Alert Level 1 bleaching conditions are also expected in the Tuamotu Archipelago in the next 1-4 weeks and in Tuvalu in the next 5-8 weeks.

–Robertscribbler (More: The Permanent Global Coral Bleaching Event | robertscribbler.)


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