Arctic scientists have warned that the increasingly rapid melting of the ice cap risks triggering 19 “tipping points” in the region that could have catastrophic consequences around the globe.
The Arctic Resilience Report found that the effects of Arctic warming could be felt as far away as the Indian Ocean, in a stark warning that changes in the region could cause uncontrollable climate change at a global level.
Temperatures in the Arctic are currently about 20C above what would be expected for the time of year, which scientists describe as “off the charts”. Sea ice is at the lowest extent ever recorded for the time of year.
“The warning signals are getting louder,” said Marcus Carson of the Stockholm Environment Institute and one of the lead authors of the report. “[These developments] also make the potential for triggering [tipping points] and feedback loops much larger.”
Climate tipping points occur when a natural system, such as the polar ice cap, undergoes sudden or overwhelming change that has a profound effect on surrounding ecosystems, often irreversible.
In the Arctic, the tipping points identified in the new report, published on Friday, include: growth in vegetation on tundra, which replaces reflective snow and ice with darker vegetation, thus absorbing more heat; higher releases of methane, a potent greenhouse gas, from the tundra as it warms; shifts in snow distribution that warm the ocean, resulting in altered climate patterns as far away as Asia, where the monsoon could be effected; and the collapse of some key Arctic fisheries, with knock-on effects on ocean ecosystems around the globe.
The research, compiled by 11 organizations including the Arctic Council and six universities, comes at a critical time, not only because of the current Arctic temperature rises but in political terms.
Aides to the US president-elect, Donald Trump, this week unveiled plans to remove the budget for climate change science currently used by NASA and other US federal agencies for projects such as examining Arctic changes.
“That would be a huge mistake,” said Carson, noting that much more research needs to be done on polar tipping points before we can understand the true dangers, let alone hope to tackle them. “It would be like ripping out the airplane’s cockpit instruments while you are in mid-flight.”
He added: “These are very serious problems, very serious changes are happening, but they are still poorly understood. We need more research to understand them. A lot of the major science is done by the US.”
Scientists have speculated for some years that so-called feedback mechanisms – by which the warming of one area or type of landscape has knock-on effects for whole ecosystems – could suddenly take hold and change the dynamics of Arctic ice melting from a relatively slow to a fast-moving phenomenon with unpredictable and potentially irreversible consequences for global warming. For instance, when sea ice shrinks it leaves areas of dark ocean that absorb more heat than the reflective ice, which in turn causes further shrinkage, and so on in a spiral.
The Arctic ice cap helps to cool sea and air temperatures, by reflecting much of the sun’s radiation back into space, and acting as a global cooler when winds and ocean currents swirl over and under it. It has long been known to play a key part of the global climate system, but the difficulty and expense of close monitoring have meant that scientists have only in recent years been able to make detailed assessments.
The report, billed as the first comprehensive study of ecosystems and societies in the region, found: “The potential effects of Arctic regime shifts [or tipping points] on the rest of the world are substantial.
'Extraordinarily hot' Arctic temperatures alarm scientists
The Arctic is experiencing extraordinarily hot sea surface and air temperatures, which are stopping ice forming and could lead to record lows of sea ice at the north pole next year, according to scientists.
Danish and US researchers monitoring satellites and Arctic weather stations are surprised and alarmed by air temperatures peaking at what they say is an unheard-of 20C higher than normal for the time of year. In addition, sea temperatures averaging nearly 4C higher than usual in October and November.
This is unprecedented for November,” said research professor Jennifer Francis of Rutgers university.
Temperatures have been a few degrees [b]above[/b] freezing when -25C should be expected, according to Francis. “These temperatures are literally off the charts for where they should be at this time of year. It is pretty shocking. The Arctic has been breaking records all year. It is exciting but also scary,” she said.
Francis said the near-record low sea ice extent this summer had led to a warmer than usual autumn. That in turn had reduced the temperature difference between the Arctic and mid-latitudes.
“This helped make the jet stream wavier and allowed more heat and moisture to be driven into Arctic latitudes and perpetuate the warmth. It’s a vicious circle,” she added.
This week it has been at the lowest extent ever recorded for late November. According to the US government’s National Snow and Ice Data Centre, (NSIDC), around 2m square kilometres less ice has formed since September than average.
Rasmus Tonboe, a sea ice remote sensing expert at the Danish Meteorological Institute in Copenhagen, said: “Sea surface temperatures in the Kara and Barents seas are much warmer than usual. That makes it very difficult for sea ice to freeze.
“What we are seeing is both surprising and alarming. This is faster than the models. It is alarming because it has consequences.”
The speed at which this is happening surprises me. In the Arctic the trend has been clear for years, but the speed at which it is happening is faster than anyone thought,” said Strove. "This is all headed in the same direction and picking up speed.”