Loss of Arctic sea ice: don't let the GFC distract you, climate change is happening
A reduction in Arctic sea ice isn't just a problem for polar bears, it's a problem for all of us.
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 loss?.
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 environment?.
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 CO?
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 humanity?.
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 2050?.
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.
Research in the Arctic has shown climate change is unequivocal. Carlos Duarte
Responsible members of the global society, including scientists and world leaders, must free themselves from the hypnosis of the GFC and take action to address other challenges humanity must face. We must avoid dangerous climate change, tackle environmental degradation and deal with reduced availability of critical resources.
Addressing the environmental basis of human well-being requires the concerted action of governments, scientists and industry. There must be a focus on delivering solutions rather than restating the problems.
There is huge potential for innovation. It will be capitalised by those societies able to deploy an entrepreneurial approach towards generating the needed outcomes.
Australia is strategically poised to take a leading role in developing this potential. The persistence and salience of the carbon tax debate has ensured climate change remains high in the nation's political agenda. The concentration of global human population growth in the nations that we share our time zones with has made us aware of the stresses on resource supply.
Our industry is strong and healthy and has the entrepreneurial drive to dive, guided by the best possible scientific advice, into the challenges to provide a new basis for economic growth based on tangible, sustained benefits.
Carstensen, J., Weydmann, A. 2011. Tipping points in the Arctic: Eyeballing or statistical significance. In: The Arctic in the Earth System perspective: the role of tipping points (Wassmann, P., Lenton T.M. (eds), AMBIO (in press)
Wadhams, P. 2011. Arctic ice cover, ice thickness and tipping points. In: The Arctic in the Earth System perspective: the role of tipping points (Wassmann, P., Lenton T.M. (eds), AMBIO (in press)
Lenton, T. M. 2011b. Arctic climate tipping points. In: The Arctic in the Earth System perspective: the role of tipping points (Wassmann, P., Lenton T.M. (eds), AMBIO (in press)
Duarte, C., Agustí, S., Wassmann, P., Vaqué, D., Arrieta, J.M., Alcaraz, M., Holding, J. 2011. Tipping elements in the Arctic marine ecosystem. In: The Arctic in the Earth System perspective: the role of tipping points (Wassmann, P., Lenton T.M. (eds), AMBIO (in press)
This article was originally published at The Conversation.
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