A few weeks ago, NASA announced that the area of Arctic ice is now almost as low as it was in 2007, its historic minimum.
The extent of ice has reduced to 4.33 million km² compared to the mean (1979 to 2000) of 7.04 million km². Simultaneously, three navigation routes have opened across the Arctic during the past boreal (northern) summer.
The 2011 event went relatively unnoticed, unlike that in 2007, which stirred significant international media attention. Media and political dialogues have focused society’s concerns on the Global Financial Crisis (GFC), diverting attention away from climate change.
Yet, the recent events in the Arctic are the closest manifestation of “dangerous” climate change yet realised on our planet.
Dangerous climate change is defined as change proceeding too fast for ecosystems to adapt naturally, threatening food production or preventing economic development proceeding in a sustainable manner.
Three major facts support this assertion:
1) The loss rate of Arctic sea ice in summer has accelerated, with the loss in area increasing by a factor of five since 1996¹, with ice thickness also falling at a rapid rate (43% from the 1970s to 1990s²).
2) Summer ice loss will trigger rapid changes in the Arctic. The Arctic marine ecosystems contain multiple elements that will shift in an abrupt manner when forced beyond their tipping point³. This will lead to changes in food webs and species loss⁴.
The reduced ice extent is expected, in turn, to set a number of additional physical, chemical and biological elements in motion, inducing rapid changes in the Arctic environment⁴.
- warming of seawater
- increased freshwater discharge
- loss of permafrost and ice sheets
- increased emissions of methane (a powerful greenhouse gas)
- a reduced capacity to sequester CO₂
- and changes in atmospheric circulation and chemistry, including the recent development of an ozone hole over the Arctic.
All of these environmental changes have potential global consequences for the earth system and humanity⁴.
3) Despite the immediacy of this scenario, we are ill-equipped to issue reliable forecasts. All models failed to forecast the 2007 event and have considerable difficulty in hindcasting it.
Models disagree greatly as to when the Arctic Ocean will become free of ice in late summer. There is a clear tendency for more recent forecasts to anticipate this event before 2050⁴.
Dangerous climate change is no longer a possible scenario for the future. It is a reality already in operation in the Arctic, arguably the most sensitive region of the world to climate change. It may be too late to avoid dangerous climate change there, but we can still avoid dangerous climate change elsewhere.
There is, therefore, an urgent need for society to re-start the conversation to avoid dangerous climate change.
Few economists may have predicted the GFC. But forecasts of forthcoming impacts from climate change have been well established for over two decades. This is despite a tendency of both society and the scientific community to indulge in semantic debates as an excuse to procrastinate.
We know what will happen under current patterns of emission of greenhouse gases, and increased depletion of critical resources (water, energy, food and a healthy environment), under current patterns of population growth and per capita resource use.
It is increased greenhouse gas emissions and not the financial meltdown that lead to the rapid, unambiguous changes in the Arctic.