The ice in the Arctic is melting rapidly
With the start of the industrial revolution in the early 18th century humans started to contribute CO₂ into the atmosphere at an unprecedented rate – first from coal, then from oil and gas. Since then this anthropogenic (human-caused) climate change has led to a global warming of about 1°C.
Unfortunately, the warming of the Arctic has turned out to be 2-3 times faster than the global average. In November, temperatures in parts of the Arctic rose to 20°C (36°F) above normal. In the not too distant future scientists predict the Arctic Ocean will be largely free of summertime sea ice. Observation also shows that the Greenland ice sheet is melting – contributing to rising sea levels across the world.
Sea ice extent declining rapidly
Arctic sea ice varies normally throughout the year from an area covering as much as 15,000 Km2 (1.5 times the size of Canada) in March to only 6000 Km2 in September. In recent years however, the ice cover in September has been as little as half of the normal. The image here shows the ice in September 2012 compared to normal observations by NASA. If the current trend continues the Arctic Ocean might be entirely ice-free in summer before the middle of this century.
Albedo is the fraction of solar energy reflected from the Earth back into space. Whilst ice and snow reflect 85% of the energy emitted by the sun, land and water instead absorb 85%. Due to the reduced albedo from less and less ice, the Arctic is currently about to transform itself from a thermal shield to an accelerator of global warming.
Data available for everyone
The National Snow and Ice Data Centre in Colorado (NSIDC) provides daily updates of the ice sheet – available to everyone here. The figure displayed here shows the status as of 8 December 2016, by far the lowest on record for this time of the year.
Sea ice volume declining faster than the area
The sea ice is normally between 1 and 4 metres thick and the volume has been even more reduced than the area compared with the normal over the last decades. Since 1979, the minimum volume has shrunk by 80%.
Even though it’s difficult to pinpoint a date the current trends suggest that the Arctic Ocean might be entirely ice free in the summer before the middle of this century.
The Greenland ice sheet is also melting
Greenland’s ice covers an area three times the size of Texas and is, at its thickest, more than three kilometres thick. In recent years, an average of 270 Gt (1 billion tons) of ice has been melting per year. This would be enough to fill 110 million Olympic swimming pools with water. As melting seems to accelerate, projections for sea level rise must be altered accordingly. The newest climate models project that by 2100, Greenland’s ice sheet could contribute to between 4 and 9 cm of sea level rise.
If the global warming continues there is a risk of passing a so called “Tipping Point” where melting cannot be stopped. Were the entire Greenland ice sheet to melt it would lead to a global sea level rise of 7.4 metres. This image from NASA shows melting ice on Greenland in July 2012. On 12 July, 97% of the ice surface was melting.
Consequences of the ice melting
The melting ice in the Arctic will have several consequences. Global climate change will accelerate and sea levels will rise – putting both ecosystems and livelihoods at risk. As many as a third of the world’s polar bears might be gone within 40 years, and the livelihood of the indigenous people who make the Arctic their home may go the same way. Freshwater runoff may change ocean circulations and less ice might open up new shipping routes and expose new reserves of fossil fuels.
About the author
Mr. Svein Tveitdal is a civil engineer with extensive experience from the private sector and the UN. In 1989 Svein was the founder of the Environmental Centre GRID-Arendal in Norway that is affiliated with the United Nations Environment Program (UNEP). After acting as director for almost 10 years, he joined UNEP as a division director at their headquarters in Nairobi. After leaving UNEP he started his own company, Klima2020, and also served seven years as the Environmental Ambassador to the city of Arendal, Norway.
He has served as chairman or board member in numerous private companies and public institutions. Svein's current focus is on bridging the gap between science, policy makers and the broad public to facilitate understanding of the threats and opportunities climate change poses. He is a writer, lecturer and active social media user with more than 200,000 followers on Twitter (@tveitdal). He typically communicates what is happening globally with climate change and renewable energy including the Arctic and Antarctica.
On board MS Midnatsol, Svein will give three lectures about the history of climate change, as well as the latest status on human-made global climate change and its impact, with a particular focus on the melting ice in the Arctic and Antarctica. He will talk about the Paris climate agreement, solutions and action needed, and discuss the chances we have to limit global warming to a level that will prevent the world from climate disaster. He will also talk about the threats and opportunities the green shift is posing on the business sector and the public.