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Climate ground zero: Rapid Arctic warming is a major trigger in extreme global weather events
A new report says the Arctic is ‘ground zero’ for cascading climate impacts across the planet, and is now experiencing several unprecedented events, with profound and complex impacts.
If we are to understand the recent record-breaking heatwave in the western parts of North America, extreme heat in Siberia and devastating floods in Western Europe and parts of China, we need to start taking a closer look at the Arctic. This is according to a newly released report by the Climate Crisis Advisory Group (CCAG).
As parts of Belgium, Germany and the Netherlands mop up after seeing two months of rain in 24 hours and smoke from Siberian forests wafts across the international dateline in Alaska, the World Meteorological Organization (WMO) has taken to calling what we’re currently seeing north of the equator a “summer of extremes”.
“Weather patterns over the whole northern hemisphere have shown unusual planetary wavy patterns in this summer. This has brought unprecedented heat, droughts, cold and wet conditions in various places. The connection of this large-scale disturbance of summer season with the warming of the Arctic and the heat accumulation in the ocean needs to be investigated,” said Dr Omar Baddour, head of the WMO’s Climate Monitoring and Policy Division.
The Extreme Weather Events in the Arctic and Beyond: A Global State of Emergency report says that the Arctic “is not only the most rapidly warming region on Earth, but that it may also be a key ‘ground zero’ for cascading impacts across the planet”.
CCAG, an independent, international group of experts from a range of climate-related disciplines, in its most recent report explains that “warming of the Arctic is taking place much faster than the global average temperature rise and is having implications well beyond the polar region”.
It continues that, “Temperature variability in the Arctic has been consistently more extreme than in global temperatures, and since around 1990 Arctic warming has risen above the global average by a continuously increasing margin. Over the last 30 years, the Arctic has warmed at a rate of 0.81°C per decade — more than three times faster than the global average of 0.23°C per decade. The Arctic Circle region had a more than 3.5°C increase above the pre-industrial level last summer (2020).”
The visualisation below shows the expanse of the annual minimum Arctic sea ice for each year from 1979 through 2020. “Minimum” here refers to the smallest state the perennial ice cap melts to before colder weather begins to cause ice cover to increase, according to Nasa. In 2020, the Arctic minimum sea ice covered an area of 3.36 million square kilometres.
(Source: Nasa/Goddard Space Flight Center Scientific Visualization Studio)
Why is this important?
The report explains that the rapid warming of the Arctic and melting of sea ice sets off a chain of cascading events.
“As sea ice melts, its highly reflective white surface is replaced by a highly heat-absorbing blue surface (seawater). The switch from reflection to absorption of sunlight accelerates the local temperature increase, creating a dangerous feedback that hastens climate change. The increase in ocean-absorption of the sun’s energy also accelerates long-term heating of oceans, pushing global warming further and faster,” says the CCAG report.
This may seem a far-flung issue to those in South Africa who might see this as being the exclusive preserve of the inhabitants of the Northern Hemisphere. That view would be incorrect. Professor Bruce Hewitson, South Africa national research chair on climate change and director of the Climate System Analysis Group, told Daily Maverick that though the impacts of an increasingly warm Arctic are not as direct on South Africa, it would be wrong to say there is no impact at all.
“There are a number of indirect effects or ways they can indirectly affect us. So in terms of the physical climate system, the melting of the Arctic changes what is called the global thermohaline circulation. The Agulhas Current comes around South Africa as part of this global circulation process. So there will be oceanic changes to the currents around the subcontinent as a result of what’s happening in the northern hemisphere. That’s one way that there is an indirect impact.
“The other indirect impact is on the social side. South Africa is part of a globalised socioeconomic system, so as you disrupt the Northern Hemisphere socioeconomic system you have knock-on consequences through the global trade system, through the global dependencies. It’s quite a complex picture,” Hewitson explained.
“The main message is that whatever happens in one part of the climate system is not independent of what happens everywhere else. There are linkages and connections between all parts of the climate system.”
Professor Francois Engelbrecht is a leading climatologist, atmospheric modelling specialist and one of the lead authors of the IPCC’s Special Report on Global Warming of 1.5°C. He told Daily Maverick that, “We should try to restrict global warming to 1.5°C and the number one reason for that is that the constantly refining climate science has determined that the threshold at which the Greenland ice cap may start to reverse in an irreversible way may in fact be somewhere between 1.5 and 2°C of global warming. So staying below 2° may not even be enough to prevent the irreversible melting of the Greenland ice cap.
“It will take many centuries for the ice sheets to melt away completely if the process is triggered, but still it means our generation will commit future generations to a different world where sea levels are about 12 metres higher than they are today,” he explained.
“In that scenario, we will of course face what is currently regarded as the worst case of what we may see in terms of sea-level rise in this century, which is an increase of about one metre by the end of this century. Now one metre of sea-level rise is already very harmful because that is enough to displace hundreds of millions of people from low-lying areas of the world.”
(Source: Nasa Climate Change website)
The CCAG report further reiterates that the “loss of ice in the Arctic is accompanied by significant changes across the globe as weather systems react”. The loss of ice in the Arctic, it reads, is also a “driver for more rapid global heating and disastrously rapid global sea-level rise and extreme weather events”.
Professor in Earth System Science, Johan Rockström, director of the Potsdam Institute for Climate Impact Research, said: “The systematic occurrence of super-extremes across the world in 2021 cannot be explained only by the 1.2°C of global warming we have caused so far. Either we have experienced unthinkable bad luck — or there is something else at play. And the candidate is the accelerated warming and ice melt in the Arctic, slowing down the northern jet stream.
“This has made weather systems stationary, causing more rain and more heat, and is slowing down the ocean conveyor belt of heat in the North Atlantic, impacting on regional weather in Europe and the monsoon systems over the Tropics. Not only is this happening at lower global warming than anticipated, the impacts are more severe than expected.
“In short, what is happening now is not well understood. It raises deep concerns though. And we know enough to urgently pull the brakes on fossil fuels and the destruction of nature,” he said. DM/OBP
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