Teetering on an Arctic tipping point
We are seeing the first signs of dangerous climate change in the Arctic. This is our warning that humanity is facing a dire future.
The Arctic region is fast approaching a series of ‘tipping points’ that could trigger an abrupt domino effect of large-scale climate change across the entire planet. The region contains arguably the greatest concentration of potential tipping elements.
If set in motion, these can generate profound alterations which will place the Arctic not at the periphery, but at the core of the Earth system. There is evidence that these chain reactions have begun. This has major consequences not just for nature, but for the future of humankind as the changes progress.
Research shows that the Arctic is now warming at three times the global average. The loss of Arctic summer sea-ice forecast over the next four decades – if not before – is expected to have abrupt knock-on effects in northern mid-latitudes, including Beijing, Tokyo, London, Moscow, Berlin and New York. The loss of sea ice – which melted faster in summer than predicted – is linked tentatively to recent extreme cold winters in Europe.
Arctic records show unambiguously that sea ice volume has declined dramatically over the past two decades. In the next 10 years, summer sea ice could be largely confined to north of coastal Greenland and Ellesmere Island, and is likely to disappear entirely by mid-century.
Some environmental and biological elements, including weakening of the oceanic biological carbon pump and the thermohaline circulation,melting of the Greenland ice cap, thawing of Arctic permafrost and methane hydrate deposit, the decline of forest and peat fires in the boreal region, may be linked in a domino effect of tipping points that cascade rapidly once this summer sea ice is lost.
Despite this danger, semantic confusion masquerading as scientific debate – although providing excellent media fodder – had delayed an urgent need to start managing the reality of dangerous climate change in the Arctic.
And of course there are those who benefit from a warmer Arctic. A drop in Arctic ice has opened new shipping routes, expanded oil, gas, and mineral exploitation, increased military and research use, and led to new harbours, houses, roads, airports, power stations and other support facilities.
It has triggered a new gold rush to access these resources, with recent struggles by China, Brazil and India to join the Arctic Council where the split of these resources is being discussed. Not everyone is in favour of reducing the impact of warming on Arctic ice.
But all of us need to take this melting seriously. Top predators such as polar bears are declining. More methane gas is entering the atmosphere as permafrosts and submarine methane hydrates thaw. Freshwater discharge has increased 30 per cent in recent years. And the Arctic Sea is warming faster as the ice cap melts, trapping more solar heat instead of reflecting it back into space, since ice reflects about 90 per cent of the indecent solar radiation compared to the absorption of 60 per cent of solar radiation by an open ocean surface devoid of ice.
In the subarctic region, dieback of the boreal forest and desiccation of peat deposits is leading to uncontrolled peat fires (such as those that plagued Russia in the summer of 2010) increases with warmer weather. This burning will further enhance greenhouse gas emissions.
We expect the Arctic will switch from being a carbon dioxide sink to become instead a source of greenhouse gases if seawater temperatures rise 4-5°C.
The rate of Arctic climate change is now faster than ecosystems and traditional Arctic societies can adapt to. Tipping points do not have to be points of no return. Several tipping points, such as the loss of summer sea ice and melting of permafrost, may be reversible in principle – although hard in practice.
However, should these changes involve the extinction of species – such as polar bears, walruses, ice-dependent seals and more than 1000 species of ice algae – the changes could represent a point of no return.
The Arctic crisis is a test of our capacity as scientists, and as societies, to respond to abrupt climate change. We need to stop debating the existence of tipping points in the Arctic and start managing their dangerous reality.
Carlos Duarte is Director, Oceans Institute at University of Western Australia. This article was originally published on The Conversation – theconversation.edu.au
Comments on this article
250 words
In response to Tim Northcott:
1) 250 words is not a lot.
2) The absence of other references does not imply that they do not exist.
3) New theories need to be consistent with all the facts, not just some. For example the assertion that CO2 increase can be explained by vulcanism needs to also explain why C13/C12 ratios and O2/N2 ratios are both also falling.
The ones that matter in terms of ice melt are surface ones
In response to Joseph Ellul:
I take your point regarding the speed of deep ocean currents.
Most heat exchange with the atmosphere is with the surface currents. Heat exchange with the deep ocean, is done in the upwellings, and subduction zones in the Great Southern ocean, and it is relatively minor. There is not much heat flow from surface currents to deep ocean currents.
In the short term, climate change has little effect on the temperature of these lower currents, nor do they have much effect on climate change.
Similarly with the Antarctic ice sheet. In fact the approximate 1000-year lag between the withdrawal of Nthn hemisphere ice sheets and the Antarctic ice sheet is thought to be because of the huge amount of latent heat stored in that ice sheet.
Luckily for us, the volume of water in these deeper currents is huge, and a lot of the CO2 we have been pumping into the atmosphere has been "hidden" by the absorption of CO2 in the subduction zones. Ie it is being carried into deep water.
But, the large amount of latent heat that both of these represent, has a trap. If we have, for example a 2C rise, that lasts for a century or two, then when these warm up, in particular the Antarctic ice sheets, it takes a long time to cool them down again.
Cherry picking
David,
I Didn't pick you as a cherry picker but by serving up the PDO (Pacific Decadal Oscillation) as your evidence of no trend then that is exactly what you are doing.
Currents
I was referring to deep, very deep, sea currents. The ones that really matter in the energy ( heat ) transfer from the deep to the surface.
Re: Timothy Northcott
Timothy, are you seriously suggesting we just sit back and let global warming take its course because you disagree with the majority of climate scientists who are specialists in their field?!! If you were diagnosed with cancer I somehow doubt you would simply ignore the advice of your oncologist because you thought you knew more than a medical specialist. Humans are slow-cooking the earth and I for one feel very uncomfortable leaving such a legacy for my children.
Work by Spencer, and Loehle & Scaffetta need salt
Spencer's model, and the paper by Loehle and Scaffetta have both been heavily criticised by statisticians, for using too many unconstrained parameters.
Their models have been shown to derive almost any conclusion that one could possibly ever want by playing with such unconstrained twiddle factors. See paper by Barry Dickmore.
Dickmore quotes John Von Neumann - "With four parameters I can fit an elephant, and with five, I can make him wiggle his trunk".
From this graph of PDO variations it is hard to see any significant 60-year oscillation. See: http://i41.tinypic.com/104gozo.png
Scaffetta has been criticised for not releasing the software used to calculate the data for their paper.
Independent studies attempting to look at the same data sets using the methods described in their paper apparently do not come up with the same numbers.
It's not the cycle
Timothy,
I'm just reflecting in simple terms the conclusions that virtually all climate scientists have reached.
So I guess you are calling a whole scientific discipline stupid.
Of course there are cycles which we humans have no control over. What the climate scientists are talking about is human induced climate change due to burning fossil fuels and which already is changing the climate at an unprecedented pace. This we can do something about... but time is running out.
We are responsible for the warming ... that's what many many lines of science are concluding ... and so it's our fault that the world is heading towards 4C (or more) warming. There is no doubt that if this happens, it will have a catastrophic effect on humankind.
It is vitally important that the facts stand here. Hopefully at some time soon decision makers will pay attention and take actions to mitigate the damage.
It's the Cycle, Stupid
Keith
Get used to the idea that millions upon millions of tonnes of CO2 will continue to be released into the atmosphere and expect the cycles below to continue until the next cooling phase. Study these graphs carefully:
http://www.appinsys.com/globalwarming/SixtyYearCycle.htm
They tell a story far better than any computer climate model has !
overwhelming acceptance of facts
Timothy,
Once more you use a tea party tactic. You seek to obfuscate and make it look as if things are not as they are.
The reality is that by a huge margin, researchers in the field accept the facts... and the facts are diverse and deep.
This is not about cycles of climate change. It is about humans deliberately releasing massive amounts of CO2. The results are what physics says will happen: we are seeing heat retention by the earth and hence global warming. It is our fault that the world is warming and we shall bear the consequences if we don't stop. It is close to being too late. The experts are clear that the world won't support more than 1 billion people if we get 4C temperature rise (where we are heading)..... this is a very big deal.
The recent Wall St Journal denialist piece was signed by 16 "experts", a couple of whom were members of the US National Academy of Sciences. A letter signed by 255 academicians was not published by the same paper.... that's less than 1% denialist academicians on this metric.
Take any metric that you want and you'll see that the number of scientists denying the facts is vanishingly small.
That 97%
C'mon Keith
That 97% statistic is based on only 79 climatologists, and that those participating were self-selected. There are two concerns here. The first is sample size. While climate science isn't a massive field, 79 participants is fairly small. To claim definitely that 97% believe this or that you would need to poll significantly more people. The second concern is the fact that the scientists were self-selected by an online survey. This may not have led to a representative sample.
http://climatequotes.com/2011/02/10/study-claiming-97-of-climate-scientists-agree-is-flawed/
The current warming the planet is experiencing has happened before just as the planet will again plunge into another ice age. It's all what scientists call - Cycles.
most people??
Timothy,
The figure is that 97% of climate scientists accept the facts of climate change... and these are the experts. So your "most people" is less than 3%.
... unless you think that your sixth sense (belief??) is better than years of hard analysis.
Everything about your posts smacks of denialist attempts to divert from the seriousness of the rapid climate change that the world is experiencing.
Climate Change & Mr LeComte
"Dont you love the way denialists, first reject evidence of any climate change, then when it suits them, accept change, but deny the possibility of any ill-effects"
Mr LeComte you seem to have a memory problem as we covered this last week, but just for you I will re-iterate my position.
The Climate has and always will change, there IS no set baseline temperature from which to measure global temperature i.e 1850 and I like most people are skeptic of the theory of AGW.
Ocean currents take hundreds or thousands of years?
In response to Joseph Ellul:
What rot.
Very slow moving currents such the North American Drift Current have velocitys of around 3cm/sec. That is around 950km/year.
The Gulf Stream has speeds around 2.5m/sec.
How lazy are these people - he could have tested such a comment in less than 2 minutes.
"No Tipping Point"?
Does Mr Northcott seriously believe that cimate scientists are unaware of the Holocene Warm period? I doubt it - he's just being his usual mischievous self.
The primary point of this article, ignored by Mr Northcott (assumedly being inconvenient), is not that warming is occurring, but the rate at which it is occurring. Rapid changes in climate have always been associated with species loss.
Another important point of the article, which has been ignored as well, is the positive feedback effects of such warming - just as true then, as now.
Since we did not have a large human population then, nor a literate one, we will not know for sure, what effect the Holocene Warm period had on most species, including our own.
Mr Northcott is simply asking us to assume that since the world somehow survived the relatively slow changes (over several millenia) of the Holocene, that this means that there is no need to be in anyway concerned by similar changes which will take less than 2 centuries.
It is wrong to make predictions of consequences of climate changes without also indicating that there is significant uncertainty as to what may or may not happen.
Nonetheless, exploring all the possible outcomes is simply prudent - or alternatively, you can bury your head in the sand like Mr Northcott.
Dont you love the way denialists, first reject evidence of any climate change, then when it suits them, accept change, but deny the possibility of any ill-effects.
Teetering on Arctic tipping point
It is a known fact that ocean waters take many hundreds of years and maybe thousands to circulate and move from top to bottom and around the world. Considering this, I would suspect that any climate change now is the result of previous happenings. Also keep in mind that it is the sun that is mostly responsible for the earths constant change of weather and temperature.
Debating the existance of tipping points is non essential as it is real. It is the reason for why it is happening that is wrong. The fact is that humans need to use world resources economically and without subsidies to non economic industries. So let us use what is naturally cheaper (gas) and as other energy fuels become cheaper then we use them and so on. Eventually we will turn to a more highly efficient alternative that I suspect will be non- dangerous nuclear power. Forget wind but solar can become efficient. Forget wave as it is too costly.
Cow dung is effective as building material, cooking fuel and mosquito deterrent in very low-income eastern countries villages. It is plentiful and cheap. The carbon emisions are acceptable for these societies but not for western modern societies with our costly gas and oil heaters fitted with high tech gear that cost hundreds of kilos in carbon emisions.
not just the arctic, similar issues in the Antarctic
Latest news from Antarctica suggests major melting too ...http://www.smartplanet.com/blog/thinking-tech/worlds-largest-iceberg-bigger-than-new-york-city/10193
No Tipping Point
According to the latest research, 5,000 years ago the Arctic had 50% less ice than it does today.
Conclusion: no tipping point - no problem.
http://www.bbc.co.uk/news/science-environment-14408930