Antarctica alone is likely to have a sea level rise of 5 meters

New modeling work shows that if current climate change continues until 2100, Antarctic ice could contribute up to five meters above sea level in the coming centuries. These results do not take into account the increase related to the melting of the Greenland ice and mountain glaciers. Journal of Glaciology.

Like an ice cube outside the freezer, glaciers and ice sheets take a while to repair again when their surroundings heat up rapidly. If it takes a few minutes for the ice cube to return to equilibrium, it is estimated that the glaciers and glaciers of Greenland and Antarctica have been around for centuries, even thousands of years.

Understanding how these large glaciers adapt to current warming An important role for the hundreds of millions of people who live near the coast And their number is constantly increasing. In fact, the sea level rise expected at the end of this century would not indicate the total increase we would have achieved if global greenhouse gas emissions had not been rapidly reduced.

Several meters towards sea level rise

In this context, a team of researchers recently set out to evaluate the response to iceAntarctic (Larger) is more or less adapted to warmer climates and is maintained at this level for centuries. In other words, the climatic conditions reached in 2100 are considered stable until the next millennium, allowing the ice to reach its new equilibrium.

The study shows that the expansion of simulations carried out within the framework of the Sixth Polar Ice Model Interconnection Program (ISMIP6), along with uncontrolled warming, has hampered the contribution of Antarctic ice to sea level rise. 1.5 to 5 m in 3000, About 3.5 meters on average. Conversely, if strong and coordinated action is implemented quickly, this contribution will be equal Only Some ten centimeters.

Further, The western Antarctic ice sheet is collapsing systematically In uncontrolled warming conditions. This is due to the fact that the high-sensitivity western cap is located on a rock below sea level, unlike the eastern cap. Therefore, it is subject to dynamic instability, which, beyond a certain heating limit, can lead to displacement in many deep irreversible conditions.

A variety of consequences that depend on our current actions

The results obtained are based on the SICOPOLIS model (in summary) Simulation code for polythermal ice sheets) In total, fourteen simulations were performed in the context of uncontrolled warming and three in the context of controlled warming. In fact, the hotter the climate, the greater the uncertainty, which requires a greater number of simulations to construct a range of possibilities. Finally, it should be noted that this work does not take into account the height associated with the melting of mountain glaciers or the height associated with the retreat of the Greenland ice sheet.

⁇ This study clearly demonstrates that the impact of 21st century climate change on Antarctic ice extends beyond the 21st century. The most serious effects will probably not be seen later », Christopher Chambers summarizing the main author of the article. ” Future work will include more realistic situation-based simulations and the use of other ice models to model the effects. .