"As climate change continues to heat the planet, ice sheets and ocean currents
could destabilize each other, leading to a climate domino effect impacting 40%
of the world’s population, according to new research.
And these effects could be seen at way lower temperatures than previously
Scientists ran 3 million computer simulations of a climate model, finding that
nearly one-third resulted in disastrous domino effects even when temperature
increases were below 3.6 degrees Fahrenheit (2 degrees Celsius) above
pre-industrial levels, the upper limit set by the Paris agreement.
Climate tipping points are points of no return in the climate system. Once they
are crossed, severe, accelerated changes to the climactic systems that support
life on Earth may become irreversible, according to a report by the UN’s
Intergovernmental Panel on Climate Change (IPCC). Some of these tipping points,
such as the collapse of the Western Antarctic ice sheet, could have already
been crossed, Live Science previously reported.
In order to simulate Earth's climate on a computer, the researchers created a
simplified model that focused on how specific "dominos" in the world's climate
systems interact. Some of those dominos were things such as ice sheets, ocean
currents or weather patterns such as El Nino, and the model essentially
simulated how tipping those — for instance, by melting major ice sheets or
slowing the Atlantic conveyor belt that helps cool Europe's climate -- would
affect other dominos in the chain. The model simulated more than 3 million
possible scenarios, in which some of the dominos interacted more or less
strongly with each other.
The new study found that collapsing ice sheets, like those in West Antarctica
and Greenland, were especially likely starting points for tipping cascades. In
one disturbing scenario, cold, glacier meltwater triggered the slowing of the
Atlantic current and then — by impacting the El-Niño Southern Oscillation — led
to significantly reduced rainfall in the Amazon rainforest, which could
transform much of it into savanna.
In another scenario, substantial melting of the Greenland ice sheet would
release freshwater into the ocean and slow down Atlantic ocean currents that
transport heat from the tropics to the North Pole. This current slowdown would
then warm the Southern Ocean, destabilizing Antarctic ice sheets, which would
in turn send meltwater into the ocean and ultimately lead to more sea-level
rise. This rising sea level, in turn, would cause even more melting of the
Greenland ice sheet.
And in many of the simulated futures, climate alterations most dramatically
affected coastal regions, where 2.4 billion people, or 40% of the world’s
population, lived in 2017, according to the United Nations."
Via Robert Sanscartier.
*** Xanni ***
Chief Scientist, Xanadu
Partner, Glass Wings
Manager, Serious Cybernetics