Two recent studies have argued that limiting global temperature increase to 1.5 °C, rather than 2 °C, will substantially decrease the probability of Arctic ice cover melting away completely.
The studies, published in the international journal Nature, contend that if temperature is maintained at 2 °C, the bar set under the Paris Agreement signed within the United Nations Framework Convention on Climate Change by 197 nations, Arctic ice cover will still melt away.
The study by Alexandra Jahn, an assistant professor at the University of Colorado at Boulder, found that a 1.5 °C rise will reduce the probability of any summer ice-free conditions by the end of the century to 30 percent as opposed to 100 percent for warming of 2°C or greater. A 1.5 °C rise will also reduce the late-century probability of an ice cover below the 2012 record minimum to only 55 percent of the time, as compared with 98 percent if warming is limited to 2.0°C, and 100 percent for higher temperatures.
The study stated that if global warming increases above 2 °C, frequent ice-free conditions can be expected for several months every year. “Although sea-ice loss is generally reversible for decreasing temperatures, sea ice will only recover to current conditions if atmospheric CO2 is reduced below present-day concentrations,” according to the study.
The second study on “Ice-free Arctic projections under the Paris Agreement” found that stabilizing the global mean temperature at 1.5°C above pre-industrial levels instead of 2°C, would mean that chances of ice-free conditions in the Arctic Ocean would reduce eightfold, from one-in-five to one-in-40 years.
Current emission reduction policies are expected to limit global warming to approximately 3 °C by 2100. However, scientists have warned that this increase would still mean that permanent summer ice-free conditions will occur, which further emphasizes the need for nations to deal with the global climate change threat and honor the targets set under the Paris Agreement.
Jahn has noted in the study that preserving summer sea ice matters, given its importance for marine mammals such as polar bears, as well as for coastal erosion along the Arctic coast.
Increased temperatures due to global warming have already changed weather patterns and led to disasters such as storms, heat waves, floods, and droughts.