Two new studies, published in the journal Science on March 24, confirm the impact of global warming on rising sea levels.
Building on past climates ...
To gain an idea of the likely consequences of global warming on rising sea levels, researchers from the National Center for Atmospheric Research (NCAR) and the University of Arizona simulated computerized the last extended period of warming 130 years ago. The oceans were then at least six meters above their current level.
NCAR glaciologist Bette Otto-Bliesner and colleague Jonathan Overpeck of the University of Arizona drew on paleoclimatic data, notably from fossilized corals and ice cores.
Bette Otto-Bliesner points out that "the polar ice caps have already melted in the distant past causing the ocean level to rise sharply with temperatures that were then not much higher than today". This is why the comparison seems interesting.
… To predict our future
The two studies show that with the current and sustained increase in the concentration of greenhouse gases in the atmosphere, summer temperatures could rise by 3 to 5 ° C in the Arctic by the end of the century .
In fact, scientists from the National Snow and Ice Data Center (NSDIC) noted in a study published at the end of 2005 that, over the past four years, the average surface temperature of the Arctic Ocean was, between January and August 2005, 2 to 3 degrees Celsius higher than in the past fifty years.
At the planetary level, we rather count, in the most optimistic and desirable scenarios, on an increase of 2 ° C in the average temperature on Earth by 2100; the arctic would then experience, with a surplus of 1 to 3 ° C, climatic conditions that prevailed 130 years ago, the last hot period between the previous and the last ice age.
Note that this previous warming was then the consequence of a variation in the axis of rotation and the Earth's orbit, and not an increase in the content of greenhouse gases.