Early warning signals of wide-ranging climate change to affect Europe and Africa


Reindeer in Scotland might not be so rare

Research, published…in the journal Nature Communications, used a simulation from a highly complex model to analyse the Atlantic Meridional Overturning Circulation (AMOC), an important component of the Earth’s climate system.

It showed that early warning signals are present up to 250 years before it collapses, suggesting that scientists could monitor the real world overturning circulation for the same signals.

The AMOC is like a conveyor belt in the ocean, driven by the salinity and temperature of the water. The system transports heat energy from the tropics and Southern Hemisphere to the North Atlantic, where it is transferred to the atmosphere.

Experiments suggest that if the AMOC is ‘switched off’ by extra freshwater entering the North Atlantic, surface air temperature in the North Atlantic region would cool by around 1-3°C, with enhanced cooling of up to 8°C in the worst affected regions.

The collapse would also encourage drought in the Sahel — the area just south of the Sahara desert — and dynamic changes in sea level of up to 80cm along the coasts of Europe and North America.

“We found that natural fluctuations in the circulation were getting longer-lived as the collapse was approached, a phenomenon known as critical slowing down,” said lead author Chris Boulton.

We don’t know how close we are to a collapse of the circulation, but a real world early warning could help us prevent it, or at least prepare for the consequences” adds co-author Professor Tim Lenton.

The study is the most realistic simulation of the climate system in which this type of early warning signal has been tested.

It’s everyone’s wildest sci-fi movie. Wild only because climate change deniers have focused their paid-for-stupidity only on the aspects of climate change indicating environments with rising temperatures. Actually the whole North Atlantic current from the Gulf Stream via the Atlantic Meridional Overturning Circulation warms the north and west of Europe and the UK from what would be normal temps absent that elevator.

The Benelux countries and the UK might become more like Lapland.

My curiosity extends to changes in humidity and precipitation. The report indicates desertification south of the Sahara. I wonder if the affected areas of Europe might end up with increased precipitation. Folks in the west of Scotland, Wales and England might have to sprout webbed feet.

Thanks, Mike – GMTA

5 thoughts on “Early warning signals of wide-ranging climate change to affect Europe and Africa

  1. Meanwhile says:

    “Warmer Pacific Ocean could release millions of tons of seafloor methane” http://www.eurekalert.org/pub_releases/2014-12/uow-wpo120914.php (12/9/14) “Off the West Coast of the United States, methane gas is trapped in frozen layers below the seafloor. New research from the University of Washington shows that water at intermediate depths is warming enough to cause these carbon deposits to melt, releasing methane into the sediments and surrounding water.
    Researchers found that water off the coast of Washington is gradually warming at a depth of 500 meters, about a third of a mile down. That is the same depth where methane transforms from a solid to a gas. The research suggests that ocean warming could be triggering the release of a powerful greenhouse gas.
    “We calculate that methane equivalent in volume to the Deepwater Horizon oil spill is released every year off the Washington coast,” said Evan Solomon, a UW assistant professor of oceanography. He is co-author of a paper to appear in Geophysical Research Letters.
    Additionally: (12/4/14): Scientists have discovered an ocean current that brings El Niño’s subsurface heat into the an area off the western coast of Mexico that “provides conditions to generate abnormal amount of intense hurricanes that may threaten Mexico, the southwest of the US and the Hawaiian islands.” http://www.eurekalert.org/pub_releases/2014-12/uoha-en120414.php “The authors of the study also caution that most climate models predict a slow down of the tropical atmospheric circulation as the mean global climate warms up. This will result in extra heat stored underneath the North-eastern Pacific and thus greatly increase the probability for this region to experience more frequent intense hurricanes.” List of hurricanes and tropical cyclones that have impacted New Mexico @ http://en.wikipedia.org/wiki/List_of_New_Mexico_hurricanes

    • Cassandra says:

      “Temperature anomalies are warming faster than Earth’s average” (12/9/14) http://phys.org/news/2014-12-extreme-temperature-anomalies-faster-earth.html Research finds that spatial patterns of extreme temperature anomalies—readings well above or below the mean—are warming even faster than the overall average. Trends in extreme heat and cold are important because they have an outsized impact on water supplies, agricultural productivity and other factors related to human health and well-being.
      The researchers analyzed temperature records for the years 1881 to 2013 from HadCRUT4, a widely used data set for land and sea locations. Using monthly average temperatures at points across the globe, they sorted them into “spatial percentiles,” which represent how unusual they are by their geographic size.
      Their findings include:
      Temperatures at the cold and warm “tails” of the spatial distribution—the 5th and 95th percentiles—increased more than the overall average Earth temperature.
      Over the 130-year record, cold anomalies increased more than warm anomalies, resulting in an overall narrowing of the range of Earth’s temperatures.
      In the past 30 years, however, that pattern reversed, with warm anomalies increasing at a faster rate than cold anomalies.
      “Earth’s temperature was becoming more homogenous with time, but now it’s not.” (Scott M. Robeson, professor of geography in the College of Arts and Sciences at IU Bloomington)
      The study records separate results for the Northern and Southern Hemispheres. Temperatures are considerably more volatile in the Northern Hemisphere, an expected result because there’s considerably less land mass in the South to add complexity to weather systems.
      The study also examined anomalies during the “pause” in global warming that scientists have observed since 1998. While a 16-year-period is too short a time to draw conclusions about trends, the researchers found that warming continued at most locations on the planet and during much of the year, but that warming was offset by strong cooling during winter months in the Northern Hemisphere.
      “There really hasn’t been a pause in global warming,” Robeson said. “There’s been a pause in Northern Hemisphere winter warming.”
      It may seem counterintuitive that global warming would be accompanied by colder winter weather at some locales. But Robeson said the observation aligns with theories about climate change, which hold that amplified warming in the Arctic region produces changes in the jet stream, which can result in extended periods of cold weather at some locations in the mid-northern latitudes.”

    • and/or says:

      “Scientists who have analyzed California’s extreme drought have concluded that it is a result of natural climate variability over the past three years and that climate change caused by humans has played little role.” http://www.nytimes.com/2014/12/09/science/earth/california-drought-is-said-to-have-natural-cause-.html “The analysis, in a report prepared for the National Oceanic and Atmospheric Administration and released Monday, found that the main driver behind the drought was patterns of water temperatures in the Pacific Ocean. They increased the likelihood that ridges of high-pressure air would form off the California coast, blocking winter storms.”
      See also “Climate Change and the Record 2014 California Drought” by Michael E. Mann, Director of Penn State Earth System Science Center ( http://www.huffingtonpost.com/michael-e-mann/climate-change-and-the-re_b_6288402.html ) “Just a couple months ago, I critiqued a pair of studies that disputed any linkage between human-caused climate change and the exceptional 2014 California drought. Now comes yet another study (“Causes and Predictability of the 2011-14 California Drought”) with the imprimatur of the National Oceanic and Atmospheric Administration (NOAA), announced with great fanfare (a NOAA press conference), drawing yet again the same conclusion. My criticisms of the latest study are yet again basically the same, but for reasons I explain below, that conclusion is even more implausible now than it was just two months ago.”

  2. Cassandra says:

    While the world is absorbed in high dramas about trade wars, Syrian chemical attacks, whether Germany can extend the lifetime of diesel-powered cars, or the latest tweet from the White House, we are missing the implications of what is happening in the Atlantic Ocean. The Gulf Stream — known officially as the Atlantic Meridional Overturning Circulation or AMOC for short — is slowing down. In fact, it is at its lowest level in the past 1,600 years according to the data those scientists have available to them. https://cleantechnica.com/2018/04/15/its-the-gulf-stream-stupid-climate-scientists-warn-tipping-point-is-near/
    The Gulf Stream pumps billions of gallons of warm water northward from the equator along the east coast of the United States before turning east toward Europe. Take away that heat and Europe becomes up to 10ºC cooler in winter, parts of Africa become more arid, and sea level rise along the eastern seaboard of the United States increases. Flow in the Gulf Stream is down 15% since 1950. How much water is that? It is equivalent to 15 Amazon rivers and 3 times more than all the rivers on Earth combined.

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