Post by Andrei Tchentchik on Mar 1, 2020 14:21:14 GMT 2
(.#A.042).- Climate change is weighing heavily on oceans and ice, 25 Sept. 2019.
Climate change is weighing heavily on oceans and ice, 25 Sept. 2019.
AFP, published on Wednesday, September 25, 2019.
Pieces of iceberg float in the sea in front of the Apusiajik glacier near Kulusuk
in southeastern Greenland on August 17, 2019.
Some consequences of climate change on the oceans and icy regions of the planet are irreversible and Humanity must be prepared, warn scientists.
The UN climate experts report (Giec) adopted this week in Monaco has a long list of devastating impacts, starting with the rising waters.
- The oceans are warming up -
SPONGE : The oceans have absorbed a quarter of the greenhouse gases emitted by humans and more than 90% of the heat resulting from climate change. As a result, the seas of the blue planet have become warmer, more acidic and less salty. And the Giec predicts that they will aspire 2 to 4 times more heat by 2100, in an optimistic scenario.
MARINE CANICLES : The frequency, intensity and extent of marine heat waves, such as those that devastated the Great Barrier Reef, have increased.
EL NINO : Extreme El Niño events - which encourage forest fires, cyclones and epidemics - are expected to be twice as frequent, even with lower CO2 emissions.
FOOD : If emissions are not reduced, the maximum potential for fish catches could be reduced by 20 to 24% by the end of the century compared to 1896-2005.
Marine species, from plankton to fish and mammals, have moved hundreds of kilometers since the 1950s.
- The sea goes up -
LEVEL OF THE SEA : Compared with the period 1980-2000, the level of the oceans is expected to increase by about 43 centimeters by 2100 in a world at + 2 ° C, but by 84 cm in a world at + 3 ° C or + 4 ° C, warming towards which current trends lead us.
In the 22nd century, the rate of sea level rise could be 100 times faster, from 3.6 millimeters per year today to "several centimeters", and then reach up to several meters in total by 2300 if emissions are not reduced.
ADAPTATION : building up flood protection could reduce flood risk by 100 to 1,000 times, provided you invest "tens to hundreds of billions of dollars a year".
The poorest regions will probably not be able to afford these major projects, especially small island states that are in danger of becoming uninhabitable and could be forced to relocate their population.
WETLANDS : 20% to 90% of wetlands are expected to be lost by 2100 due to projected sea level rise.
- The sea dies -
OXYGEN : The oxygen concentration in the marine environment has decreased by 2% in 60 years, and should lose an additional 3 or 4% if we do not reduce CO2 emissions.
DEAD AREAS : Warming water and coastal pollution are already responsible for the expansion of "dead zones", where too low oxygen levels prevent marine life.
CORALS : Coral reefs, of which half a billion people depend on food and coastal protection, will suffer significant losses or even extinctions locally, even with warming limited to + 1.5 ° C compared to the previous era. pre-industrial.
- The ice melts -
GLACIAL CAPS : The two ice caps on the planet, in Antarctica and Greenland, have lost an average of 430 billion tonnes each year since 2006, becoming the main source of rising sea levels.
GLACIERS : Glaciers, on which more than two billion people depend for freshwater, also shrink. Those of low altitude in the Alps, the Caucasus or Scandinavia could lose 80% of their volume by 2100 and many could disappear even by limiting the warming.
SNOW : The mountains are expected to lose a significant portion of their snow cover, with significant impacts on agriculture, tourism and energy supply.
- Permafrost too -
PERMAFROST : about a quarter of the surface of permafrost, this layer of permanently frozen ground, could melt by 2100 even in an optimistic scenario. This could release tens or even hundreds of billions of tons of CO2 and methane into the atmosphere.
F I N .
Climate change is weighing heavily on oceans and ice, 25 Sept. 2019.
AFP, published on Wednesday, September 25, 2019.
Pieces of iceberg float in the sea in front of the Apusiajik glacier near Kulusuk
in southeastern Greenland on August 17, 2019.
Some consequences of climate change on the oceans and icy regions of the planet are irreversible and Humanity must be prepared, warn scientists.
The UN climate experts report (Giec) adopted this week in Monaco has a long list of devastating impacts, starting with the rising waters.
- The oceans are warming up -
SPONGE : The oceans have absorbed a quarter of the greenhouse gases emitted by humans and more than 90% of the heat resulting from climate change. As a result, the seas of the blue planet have become warmer, more acidic and less salty. And the Giec predicts that they will aspire 2 to 4 times more heat by 2100, in an optimistic scenario.
MARINE CANICLES : The frequency, intensity and extent of marine heat waves, such as those that devastated the Great Barrier Reef, have increased.
EL NINO : Extreme El Niño events - which encourage forest fires, cyclones and epidemics - are expected to be twice as frequent, even with lower CO2 emissions.
FOOD : If emissions are not reduced, the maximum potential for fish catches could be reduced by 20 to 24% by the end of the century compared to 1896-2005.
Marine species, from plankton to fish and mammals, have moved hundreds of kilometers since the 1950s.
- The sea goes up -
LEVEL OF THE SEA : Compared with the period 1980-2000, the level of the oceans is expected to increase by about 43 centimeters by 2100 in a world at + 2 ° C, but by 84 cm in a world at + 3 ° C or + 4 ° C, warming towards which current trends lead us.
In the 22nd century, the rate of sea level rise could be 100 times faster, from 3.6 millimeters per year today to "several centimeters", and then reach up to several meters in total by 2300 if emissions are not reduced.
ADAPTATION : building up flood protection could reduce flood risk by 100 to 1,000 times, provided you invest "tens to hundreds of billions of dollars a year".
The poorest regions will probably not be able to afford these major projects, especially small island states that are in danger of becoming uninhabitable and could be forced to relocate their population.
WETLANDS : 20% to 90% of wetlands are expected to be lost by 2100 due to projected sea level rise.
- The sea dies -
OXYGEN : The oxygen concentration in the marine environment has decreased by 2% in 60 years, and should lose an additional 3 or 4% if we do not reduce CO2 emissions.
DEAD AREAS : Warming water and coastal pollution are already responsible for the expansion of "dead zones", where too low oxygen levels prevent marine life.
CORALS : Coral reefs, of which half a billion people depend on food and coastal protection, will suffer significant losses or even extinctions locally, even with warming limited to + 1.5 ° C compared to the previous era. pre-industrial.
- The ice melts -
GLACIAL CAPS : The two ice caps on the planet, in Antarctica and Greenland, have lost an average of 430 billion tonnes each year since 2006, becoming the main source of rising sea levels.
GLACIERS : Glaciers, on which more than two billion people depend for freshwater, also shrink. Those of low altitude in the Alps, the Caucasus or Scandinavia could lose 80% of their volume by 2100 and many could disappear even by limiting the warming.
SNOW : The mountains are expected to lose a significant portion of their snow cover, with significant impacts on agriculture, tourism and energy supply.
- Permafrost too -
PERMAFROST : about a quarter of the surface of permafrost, this layer of permanently frozen ground, could melt by 2100 even in an optimistic scenario. This could release tens or even hundreds of billions of tons of CO2 and methane into the atmosphere.
F I N .
