Andreas Weith / Wikimedia Commons
20 Dec 2021 Tukio Kushughulikia Mazingira

Another wake-up call: sea ice loss is speeding up

Andreas Weith / Wikimedia Commons

Last week, the World Meteorological Organization (WMO) confirmed the highest temperature ever recorded in the Arctic, 38C, on 20 June 2020. This warming is causing previously permanently frozen permafrost below ground to thaw.

The Arctic is now amongst the fastest-warming regions on the planet, heating at more than twice the global average. Scientists are worried because carbon dioxide and methane previously locked up below ground are released as permafrost thaws.

Methane is the primary contributor to the formation of ground-level ozone, a hazardous air pollutant and greenhouse gas, exposure to which causes 1 million premature deaths every year.

Methane is also a powerful greenhouse gas. Over a 20-year period, it is 80 times more potent at warming than carbon dioxide.

We asked United Nations Environment Programme (UNEP) climate change expert Pascal Peduzzi to explain the significance of sea ice loss.

UNEP: What happens to sea ice in the Arctic may seem remote and irrelevant to our daily lives. Why does sea ice loss matter?

Pascal Peduzzi: It matters because the extent of sea ice affects local ecosystems, regional and global weather patterns, and ocean temperatures and circulation. If Arctic sea ice continues to shrink, we may see a summer ice-free Arctic Ocean by the mid-2040s and the disappearance of polar bears and other animals. However, there are also global consequences. Snow and ice help keep the planet cool because they reflect the sun’s rays back into space. Warmer temperatures mean Arctic sea ice is reduced, ocean temperatures rise, and the warmer water (with a bigger volume) contributes to sea-level rise.

The lowest extent of sea ice on record was in 2012. 2020’s extent was almost as small, and while 2021 was slightly higher, the trend is clear. In addition, in 2020, the area of Arctic Sea Ice was the lowest on record for the month of July.

UNEP: Why is this happening? What is causing the loss of sea ice?

PP: Increasing emissions of greenhouse gases, principally carbon dioxide (CO 2), are to blame. The global trend in the increase in CO2 concentration is not only rising but accelerating. If we compare the same month of May, in 1960 it was +0.9 parts per million (ppm) per year, in 1980 +1.21 ppm; in 2000 +1.83 ppm and in 2021 it is +2.48 ppm/year. Global heating is real. There is a strong correlation in the long-term trends between CO2 emissions and atmospheric CO2 levels and we’re in danger of missing key Paris Agreement goals as the emissions gap widens.

UNEP: What is UNEP doing to highlight the dangers?

PP: UNEP’s Emissions Gap Report 2021: The Heat is On along with the World Environment Situation Room are painting a worrying picture. Monthly global temperatures for January, February, March and July 2020, were the second warmest since records began in 1880, while in April, May and June 2020 they were the warmest ever on record since 1880. 2021 was slightly cooler, however, the month of July was ranking 3rd on records. Severe extremes were recorded in various regions of the world.

UNEP: What are the implications?

PP: Reduced Arctic sea ice means increased ocean temperatures. Combined with melting glaciers on land, this contributes to sea-level rise, which is accelerating. Between 1994 and 2010 sea-level rise averaged 3.3 mm per year, but since 2010 it has been rising at an average of 4.4 mm per year.

Graph
Graph showing the Arctic sea-level rise between 1980-2020. Graph by UNEP

A warming world threatens the planet’s library of life, including our own existence. We need to change the way we do agriculture, our industry, the way we travel, and how we heat and cool our homes. We need to ramp up renewable energy and rapidly phase out fossil fuels. We need to implement nature-based solutions and introduce a circular economy. Solutions exist, but their implementation is too slow. We also need more data and science. Governments need to get serious about climate action.

The United Nations Decade of Ocean Science for Sustainable Development (2021 - 2030) proclaimed in December 2017, will provide a common framework to ensure that ocean science can fully support countries’ actions to sustainably manage the oceans and more particularly to achieve the 2030 Agenda for Sustainable Development.

For more information, please contact Pascal Peduzzi: Pascal.Peduzzi@un.org