Search Results for Tag: Antarctic
Melting glacier risk to seabed ecosystem
On my first visit to the Arctic in 2007, I went out into the Kongsfjord at Ny Alesund, Spitsbergen, with some marine biologists working out of Koldewey station, run jointly by France and Germany. It was June, and the glaciers at the end of the fjord were just starting to thaw. While I was enjoying the blues, whites and greys of the sea, ice and sky, the researchers in the small boat got very excited when they saw the water turned brown, where sediment was flowing into the fjord from the retreating glacier.
“Who turned off the light up there”?
They had been waiting impatiently for the thaw to set in, because their research focus was on what that means for the life forms on the seabed, or benthos. Clearly, if you live down on the sea floor, the intrusion of brown mud and other sediment changes your surroundings. Not least, it means less light coming down from above. Now while a certain amount of that is going to happen naturally every year with the changing seasons, the question is: what happens if there is a big increase in sediment coming in because of increasing melt through climate change?
I was interested to hear about a study published this week in Science Advances, dealing with that same question in the Antarctic. The findings indicate that melting coastal glaciers are having an impact on the entire ecosystem on the seafloor, leading to a loss of biodiversity through sedimentation. The scientists were looking at the West Antarctic peninsula, where the temperature has risen almost five times faster than the global average in the last fifty years.
Global warming changes seafloor communities
The study, published by experts from Argentina, Germany and Great Britain, including the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI,) is based on repeated research dives. The scientists believe increased levels of suspended sediment in the water caused the dwindling biodiversity registered in the coastal region. They say it occurs when the effects of global warming lead glaciers near the coast to begin melting, discharging large quantities of sediment into the seawater.
To find out exactly how and to what extent the retreat of glaciers is affecting bottom-dwelling organisms, researchers at the Dallmann Laboratory are now mapping and analysing the benthos in Potter Cove, located on King George Island off the western Antarctic Peninsula. The lab is operated by the Alfred Wegener Institute and the Argentine Antarctic Institute (IAA) as part of the Argentinian Carlini Station. Researchers have been monitoring benthic flora and fauna there for more than two decades.
In 1998, 2004 and 2010, divers photographed the species communities at three different points and at different water depths: the first, near the glacier’s edge; the second, an area less directly influenced by the glacier; and the third, in the cove’s minimally affected outer edge. They also recorded the sedimentation rates, water temperatures and other oceanographic parameters at the respective stations, so that they could correlate the biological data with these values. Their findings: some species are extremely sensitive to higher sedimentation rates.
Short sea squirts adapt better
Sea squirts are small invertebrate creatures that live on the sea floor and feed by filtering the water through their anatomies.
“Particularly tall-growing ascidians like some previously dominant sea squirt species can’t adapt to the changed conditions and die out, while their shorter relatives can readily accommodate the cloudy water and sediment cover,” says Dr Doris Abele, an AWI biologist and co-author of the study. She is worried that “the loss of important species is changing the coastal ecosystems and their highly productive food webs, and we still can’t predict the long-term consequences.”
As with so many aspects of our oceans, there is a lack of base data on how sediment from melting glaciers affects the numerous life forms on the seabed.
“It was essential to have a basis of initial data, which we could use for comparison with the changes. In the Southern Ocean we began this work comparatively late,” says the study’s first author, marine ecologist Ricardo Sahade from the University of Cordoba and Argentina’s National Scientific and Technical Research Council CONICET, who is leading the benthic long-term series. “Combining this series of observations, accompanying ecological research on important Antarctic species, and mathematical modelling allows us to forecast the changes to the ecosystem in future scenarios,” says co-author Fernando Momo from Argentina’s National University of General Sarmiento.
With scientists telling us the ice of the West Antarctic peninsula has already passed a tipping point, the question is whether scientific monitoring and research will be able to keep pace with the rapid rate at which climate warming is already having major impacts on our oceans. For many species of our seabottom-dwelling creatures, the slow pace of greenhouse gas emissions reductions may well come far too late.
See also: Antarctic glaciers retreat unstoppable
DateNovember 13, 2015 | 8:29 pm
Ice melt to motivate whizzkids?
And understanding that ice cores can tell us about 800,000 years of climate history tends to fascinate even the most unscientific of youngsters.
Not that the 160 young folk assembled recently in Bonn by the Hans-Riegel Foundation were lacking in scientific interest or talent.
The foundation, set up by the highly successful businessman who created HARIBO, (comes from HAnsRIegelBOnn, by the way) the “gummy bear” brand name, supports innovative educational projects with a view to encouraging talented young people to go into research. It awards prizes to school pupils in Germany and Austria for scientific projects.
Recently, 160 prizewinners were invited to a “Science Slam” in Bonn and a series of workshops and presentations – including a talk by renowned climate expert Mojib Latif. Mojib Latif is a professor for oceanology and climate dynamics at GEOMAR, the Helmholtz Centre for Ocean Research in Kiel, in northern Germany.
He has just been chosen as one of two winners of this year’s Deutscher Umweltpreis or German Environment Prize by the “Deutsche Bundesstiftung Umwelt”, one of Europe’s largest foundations. It’s the first time the award has been given to a climate scientist.
Latif, whose family background is Indian, is a well-known face on television. He has a talent for explaining complex climate phenomena in a way that ordinary people with no scientific background can grasp. As I listened to him addressing the young scientists, I could see how they were spellbound by his stories and anecdotes. And that makes it easier to digest the diagrams and figures that illustrate the workings of the global climate.
Latif holds his audience’s attention with a mixture of humour and examples from everyday life. He anticipates questions of the “skeptical” type, explaining the existence of natural trends and variations as well as human-made warming, and the wide range of scenarious covered by climate models.
When he turned to Greenland and to the Antarctic, I could see the fascination and curiosity in the eyes of the young audience.
The main message of this expert’s message was a mixture of concern at the rate of climate change and optimism that we have the technology to replace fossil fuels by renewables – and that the up-and-coming generation will use it to avert the worst.
Although he’s fairly certain we won’t be able to keep to the two-degree target, Latif says humankind just cannot be “so stupid” as to keep burning fossil fuels and heating up the atmosphere. If the applause of those representatives of the younger generation could be translated into positive action to combat climate change, his optimism may well be justified.
You can read what he told me in an interview after the encounter with Germany’s science whizzkids here:
DateOctober 9, 2015 | 11:08 am
TagsAntarctic, Arctic, Climate, Deutscher Umweltpreis, Geomar, Hans-Riegel Stiftung, HARIBO, ice, latif, science
Can we still avert irreversible ice sheet melt?
Earlier this week, I was able to follow up my last talk with Professor Stefan Rahmstorf from the Potsdam Institute for Climate Impact Research (PIK), after he returned from the Paris climate science forum. After the publication of the study he was involved in on paleoclimatic data linking global temperature with sea level rise, and having heard his views on the science consensus ahead of the December UN summit in Paris, I wanted to know how he views the prospects for the polar ice sheets.
A question I return to often is whether anything we do to reduce emissions from now onwards – given that huge damage has already been done by our fossil fuel emissions and that the CO2 will remain in the atmosphere for a very long time to come – can prevent the ice sheets in the Antarctic and Greenland from reaching a “tipping point”.
Professor Rahmstorf gives this definition of a “tipping point” – which can mean different things to different people in different contexts:
“Climate tipping points are points of no return, where you cannot stop a process that has been set in motion. It’s a bit analogous to the situation where you are sitting in a rowing boat and you lean over a bit to one aside and not much happens. Then you lean a bit more and a tipping point comes where the boat simply tips over. One of these points of no return is with our continental ice sheets, where their further melt-down becomes inevitable and unstoppable. And we have to realize that we have enough continental ice on this planet to raise global sea level by more than 60 metres. That means we cannot afford to lose even a very small fraction of that ice without drowning coastal cities and small island nations.”
Is the boat still afloat?
But, of course, we are already losing ice at a worrying rate. Rahmstorf cites recent research showing that at least a part of the West Antarctic ice sheet has already been destabilized.
“We probably have already crossed the tipping point for a part of West Antarctica. That is probably going to already commit us to about three metres of sea level rise.”
Of course this is not likely to happen in the very near future. But the problem with the tipping points is, of course, that there is no going back, as Rahmstorf explains:
“Sea level has already risen 20 centimetres globally since the late 19th century, due to modern global warming, which is very basic physics. It’s melting continental ice sheets. And also the oceans are being heated up, which expands the ocean water, because warm water takes up more space. And by the year 2100, with unmitigated emissions, we are looking at one meter of sea level rise, which already, for vulnerable coastal areas like delta regions, like Bangladesh for example, will dramatically increase the storm surge risk. But sea level rise will not stop in the year 2100, because the ice sheets are actually quite slow to melt, and within the next decades, we will be causing a long-term sea level rise commitment by several metres for every degree of global warming that we cause.”
Greenland – and Miami, St. Petersburg, Bangladesh…
Record melting appears to be happening on Greenland at the moment. I asked Rahmstorf how safe the world’s biggest island and the largest area of freshwater ice in the northern hemisphere (See also the Ice Island in Pictures) is from reaching a point of no return. He wasn’t able to give a reassuring answer:
“We don’t know exactly where the tipping point is for the Greenland ice shield is. The IPPC estimates anywhere between one and four degrees of global warming. We are already at one degree warming, so we may well cross that tipping point in the next decades.
In the review of the relation between global temperature and sea level rise from polar ice disintegration I discussed in the last blog post, Rahmstorf and his colleagues found that just a slight further rise in temperature might equate to a rise in global sea level of up to six metres. I asked him what that would mean for the world right now:
“There would be quite a number of large coastal cities I cannot imagine could still be defended. Think of New York city for example. Or Miami would be one of the first cities to go. St. Petersburg, Alexandria, Manila – you name them. Once you are talking about metres of sea-level rise, the consequences would be quite catastrophic. Especially as it is to be feared that people will not react proactively by move away from the danger zone, but will probably stay in their cities until a major storm surge hits. Like Hurricane Katrina hitting New Orleans, which also was a case where experts had warned for a long time that the city was in danger, once the next hurricane strikes, but people still didn’t act according to the precautionary principle. As they should have, and as we must do to prevent a climatic disaster in future.”
Can we keep the ice chilled?
So what would we have to do to keep sea level in check?
“Emissions would have to be close to zero by mid-century, so we are not talking about small cosmetic adjustments, but a transformation of our energy system, decarbonization, that is getting out of the carbon-based energy system. The good news is that the technologies to do that are available. It’s all about mustering the political will. And, of course, fighting the particular interests which are opposing this transformation.”
Stefen Rahmstorf is not one of those scientists who prefer to sit on the fence and leave the interpretation of his research and their implications up to the politicians. He is convinced only rapid action to stop emissions can prevent catastrophic climate change – including the melt of the polar ice.
I have interviewed him on previous occasions in the last few years. This time, I was surprised by his optimistic stance on whether the international community can still do anything in time to stop global warming from reaching the dangerous level of two degrees (or even one point five, as Rahmstorf and others say would be far preferable):
“There’s still a good chance that a strong agreement coming out of the Paris summit in December could mean we could avoid the Greenland tipping point. I am cautiously optimistic that Paris will reach a meaningful agreement, not necessarily one that guarantees that we will stay below two degrees global warming, but one that will be seen in hindsight as a real turning point, from where emissions started to fall soon after. The key point is – the sooner we stop global warming, the better the chances are that we avoid future critical tipping points.”
All we need, says Rahmstorf, is the political will to make use of the technologies available, take on the fossil fuels lobby, and clean up our energy system.
Listen to my interview with Stefan Rahmstorf on DW’s Living Planet this week.
DateJuly 17, 2015 | 2:57 pm
TagsAntarctic, Arctic, Climate, Greenland, ice, irreversible ice melt, PIK, Rahmstorf, Sea level, tipping points
Polar ice set for six-metre sea level rise?
Small increases in global average temperature may eventually lead to sea level rise of six metres or more, according to evidence from past warm periods in Earth’s history.
That was the worrying message from a paper published in the journal Science this week. The researchers, part of the international “Past Global Changes” project, analysed sea levels during several warm periods in Earth’s recent history, when global average temperatures were similar to today or slightly warmer – around 1°C above pre-industrial temperatures.
I was able to talk briefly to one of the authors, Stefan Rahmstorf from the Potsdam Institute for Climate Impact Research (PIK), who was in Paris at the international scientific conference “Our common future under climate change” this week. (The article I wrote on that event, billed as the biggest climate science gathering ahead of the key COP in Paris in December, and the full interview with Rahmstorf are online now).
Rahmstorf described the new study on polar ice sheet disintegration and sea level as “a review of our state of knowledge about past changes in sea level in earth’s history, especially looking at all the data we have on past warm periods, due to the natural cycles of climate – the ice age cycles – that come from the earth’s orbit.”
He went on: ”We have had warmer times in the past, the last one was about 120,000 years ago, and we find that invariably, during these warmer times, the sea level was much higher. It was at least about six meters higher than today, even though temperatures were only a little bit higher, maybe one to three degrees warmer – depending on what period you are looking at – compared to the pre-industrial climate.”
Bad news for coastal dwellers
Not happy reading for anyone living close to the coast, if you look at temperature development today:
“Basically the message is: the kind of climate we are moving towards now – even if we limit warming to two degrees – has in the past always been associated with a sea level several metres higher, which would of course have catastrophic consequences for many coastal cities and small island nations.”
With warming currently on course to reach four degrees and more by the end of this century if greenhouse gas emissions continue on their present trajectory, this message adds yet another piece of evidence to motivate the world’s governments to come up with a new World Climate Agreement at the UN Paris summit at the end of the year – and to get moving towards a zero-carbon economy asap.
The interdisciplinary team of scientists concluded that during the last interglacial warm period between ice ages 125,000 years ago, the global average temperature was similar to the present, and this was linked to a sea-level rise of 6 to 9 metres, caused by melting ice in Greenland and Antarctica. Around 400,000 years ago, when global average temperatures were estimated to be between 1 to 2 degrees Celsius higher than –pre-industrial levels, sea level reached 6 to 13 meters higher. The lead author of the study, Andrea Dutton from the University of Florida, told journalists global average temperatures were similar to today during these recent interglacial periods, but polar temperatures were slightly higher. However, she stressed: “The poles are on course to experience similar temperatures in the coming decades”.
The Arctic is currently warming faster than the global average. IPCC estimates indicate that it could be almost two degrees warmer by 2100 compared with the temperature from 1986 to 2005 – IF the two-degree target is adhered to. Otherwise, it could rise by as much as 7.5°C.
Speed of sea level rise hard to predict
The authors of the study stress that the further back you go (they tried to estimate sea level as long as three million years ago), the more difficult it gets to calculate precisely how high sea level was, given that geological forces push and pull the Earth’s surface and can also cause vertical movement measuring tens of metres. This makes it hard to separate the geological changes in shoreline position from sea level rise caused by polar ice sheet disintegration.
Still, the authors point out that small temperature rises of between one and three degrees were, in the past, like today, linked with magnified temperature increases in the polar regions, which lasted over many thousands of years.
They conclude that even keeping to the overall two-degree warming limit is no guarantee: “Even this level sustained over a long period of time carries substantial risk of unmanageable sea level rise, not least because carbon dioxide remains in the atmosphere for over a thousand years”.
The researchers are not able to say how fast sea levels rose in the past, which would be a key piece of information for planning adaptation. Further research will be necessary for that.
Co-author Anders Carlson of Oregon State University says by confirming that our present climate is warming to a level associated with significant polar ice-sheet loss in the past, the study us providing “perhaps the most societally relevant information the paleo record can provide”.
Carlson heads the PALSEA2 Working Group, hosted by the Past Global Changes (PAGES) project, which used computer models and evidence from around the globe to come up with the conclusions in the study.
Stefan Rahmstorf draws a clear conclusion from the results of this research and other recent studies on instabilities in the Antarctic ice sheet and changes in ocean currents:
“This really calls for limiting warming to 1.5 degrees. And it is still feasible to limit warming to 1.5 degrees. But that requires a much stronger political will than we currently have”.
Still, the Potsdam professor is more optimistic than he used to be that advances in renewable energy and other technologies and growing awareness of the negative impacts climate change is already having around the globe could mean the UN Paris conference at the end of the year will mark a turning point.
Not that he thinks Paris can “do it all”. As you’ll see if you read my interview with him, he is hoping for the start of a process similar to the Montreal Protocol, where the original agreement was not too strong, but worked eventually by toughening up as it went along. Now that would be really good news. He told me it was time to “turn the tide of rising emissions”. Here’s hoping it happens in time to keep the sea level around the world well below that six metres that were there in the past.
DateJuly 10, 2015 | 2:30 pm
Icy hotspots in focus at climate talks?
With western Europe sweltering in a record-breaking heatwave, climate scientists are meeting in Paris this week for what is regarded as the last major climate science conference before the key COP 21 in Paris at the end of this year. “Our Common Future under Climate Change” wants to be “solutions-focused”, but starts off with a resumé of the state of science as a basis.
One of the topics on the wide agenda is, of course, the cryosphere, with scientists reporting on rapid changes in the Arctic ice and permafrost, and worrying developments in the Antarctic.
As conference after conference works to prepare a new World Climate Agreement, to take effect in 2020, the International Cryosphere Climate Initiative (ICCI) is concerned that the INDCSs, or Intended Nationally Determined Contributions, i.e. the climate action countries propose to take are not in line with keeping global warming to the internationally set target of a maximum two degrees centigrade. Scientists tell us this itself would already have major impacts on the world’s ice and snow.
Climate pledges way too low
Pam Pearson, the founder and director of ICCI, told journalists during a recent visit to Bonn her indication of INDCS so far was that they are ”somewhere between 3.8 and 4.2 degrees”.
Pearson and her colleagues are working hard to make the scientific evidence on climate changes in our ice and snow regions accessible and “must-reads” for the politicians and others who are preparing to negotiate the new agreement at the Paris talks at the end of the year, to replace the Kyoto protocol. She was here in Bonn at the last round of UN preparatory climate talks last month, holding a side event and briefing media and negotiators.
Pearson was part of the original Kyoto Protocol negotiating team. She is a former U.S. diplomat with 20 years’ experience of working on global issues, including climate change. She says she resigned in 2006 in protest over changes to U.S. development policies, especially related to environmental and global issues programmes. From 2007-2009, she worked from Sweden with a variety of organizations and Arctic governments to bring attention to the potential benefit of reductions in short-lived climate forcers to the Arctic climate, culminating in Arctic Council ministerial-level action in the Tromsø Declaration of 2009.
Pearson founded ICCI immediately after COP 15 to bring greater attention and policy focus to the “rapid and markedly similar changes occurring to cryosphere regions throughout the globe”, and their importance for the global climate system.
IPCC reports already out of date
At the briefing in Bonn a couple of weeks ago, she said:
“Certainly through AR5, (the 5th Assessment Report of the IPCC) the science is available to feed into the negotiations. But I think what we see as a cryosphere organization, participating as civil society in the negotiations – and I think also, very importantly, what the IPCC scientists see – is a lack of understanding of the urgency of slowing down these processes and the fact that they are irreversible. This is not like air or water pollution, where if you clean it up it will go back to the way it was before. It cannot go back to the way it was before and I think that is the most important aspect that still has not made its way into the negotiations”.
Scientists taking part in the event organized by the ICCI in Bonn stressed that a lot of major developments relating especially to Antarctica and to permafrost in the northern hemisphere was not available in time for that IPCC report. This means the scientific basis of AR5 is already way out of date, and that it does not include very recent important occurrences.
Sea ice in decline
Dirk Notz from the Max Planck Institute for Meteorology in Hamburg heads a research group focusing on sea ice and rapid changes in the Arctic and Antarctic.
He told journalists in Bonn: “Over the last 10 years or so we’ve roughly seen a fifty percent loss of Arctic sea ice area, so this ice is currently retreating very, very rapidly. In the Antarctic, some people are talking about the increase of sea ice. Just to put things into perspective: there is a slight increase, but it’s nothing compared to the very rapid loss that we’ve seen in the Arctic.“
The slight increase in sea ice in the Antarctic is certainly not an indicator that could disprove climate warming, as some of a skeptical persuasion would like to have us believe.
“In the Antarctic, the changes in sea ice are locally very different. We have an increase in some areas and a decrease in other areas. This increase in one area of the southern ocean is largely driven by changes in the surface pressure field. So the winds are blowing stronger off shore in the Antarctic, pushing the ice out onto the ocean, and this is why we have more sea ice now than we used to have in the past. Our understanding currently says that these changes in the wind field are currently driven by anthropogenic changes of the climate system,“ said Notz.
He stresses that as far as the Arctic is concerned, the loss of sea ice is very clearly linked to the increase in CO2. The more CO2 we have in the atmosphere, the less sea ice we have in the Arctic.
Changing the face of the planet
Notz stresses the speed with which humankind is currently changing the face of the earth:
“Currently in the Arctic, a complete landscape is disappearing. It’s a landscape that has been around for thousands of years, and it’s a landscape our generation is currently removing from the planet, possibly for a very long time. I think culturally, that’s a very big change we are seeing.”
At the same time, he says the decline in the Arctic sea ice could be seen as a very clear warning sign:
“Temperature evolution of the planet for the past 50 thousand years or so shows that for the past 10 thousand years or so, climate on the planet has been extremely stable. And the loss of sea ice in the Arctic might be an indication that we are ending this period of a very stable climate in the Arctic just now. This might be the very first, very clear sign of a very clear change in the climatic conditions, like nothing we’ve seen in the past 10,000 years since we’ve had our cultures as humans.”
Simulations indicate that Arctic summer sea ice might be gone by the middle of this century. But Notz stresses that we can still influence this:
“The future sea ice loss both in the Arctic and the Antarctic depends on future CO2 emissions. A rapid loss of Arctic summer sea ice in this decade is possible but unlikely. Only a very rapid reduction of CO2 might allow for the survival of Arctic summer sea ice beyond this century.”
Antarctic ice not eternal
Whereas until very recently, the Antarctic ice was regarded as safe from climate warming, research in the last few years has indicated that even in that area, some possibly irreversible processes are underway. This relates to land ice rather than sea ice.
Ricarda Winckelmann is a scientist with the Potsdam Institute for Climate Impact research (PIK). She told journalists and climate negotiators at the Bonn talks that Antarctica could be regarded as the “sea level giant”. The global sea level would rise by five metres if West Antarctica’s ice sheet melted completely, 50 metres for the East Antarctic ice sheet.
“Over the past years, a couple of regions in Antarctica have really caught our attention. There are four hotspots. They have all changed rapidly. There have been a number of dynamic changes in these regions, but they all have something in common, and that is that they bear the possibility of a dynamic instability. Some of them have actually crossed that threshold, some of them might cross it in the near future. But they all underlie the same mechanism. That is called the marine ice sheet instability. It’s based on the fact that the bottom topography has a certain shape, and it’s a purely mechanical, self-enforcing mechanism. So it’s sort of driving itself. If you have a retreat of a certain region that undergoes this mechanism, it means you cannot stop it. “
The hotspots she refers to are the Amundsen Basin in West Antarctica, comprising the Pine Island and Thwaites glaciers, which are the fastest glaciers in Antarctica:
“It has been shown in a number of studies last year that it actually has tipped. Meaning it has crossed that threshold, and is now undergoing irreversible change. So all of these glaciers will drain into the ocean and we will lose a volume that is equivalent to about a metre of global sea level. The question is how fast this is going to happen.”
Next comes the Antarctic peninsula, where very recent research has indicated that warm water is reaching the ice shelves, leading to melting and dynamic thinning.
Even in East Antarctica, which was long considered virtually immune to climate change, Winckelmann and her colleagues have found signs that this same mechanism might be at work, for instance with Totten Glacier:
“There is a very recent publication from this year, showing that (…) this could possibly undergo the same instability mechanism. Totten glacier currently has the largest thinning rate in East Antarctica. And it contains as much volume as the entire West Antarctic ice sheet put together. So it’s 3.5 metres worth of global sea level rise, if this region tips”, says the Potsdam expert.
Pulling the plug?
The other problematic area is the Wilkes Basin.
“We found that there is something called an ice plug, and if you pull it, you trigger this instability mechanism, and lose the entire drainage basin. What’s really striking is that this ice plug is comparably small, with a sea-level equivalent of less than 80 mm. But if you lose that ice plug, you will get self-sustained sea level rise over a long period of time, of three to four metres.“
This research is all so new that it was not included in the last IPCC assessment:
“We’ve known that this dynamic mechanism exists for a long time, it was first proposed in the 1970s. But the observation that something like this is actually happening right now is new,” Winckelmann stresses.
Clearly, this is key information when it comes to bringing home the urgent need for rapid climate action.
Pam Pearson stresses that these changes in themselves have a feedback effect, and have an impact on the climate:
“The cryosphere is changing a lot more quickly than other parts of the world. The main focus for Paris is that these regions are moving from showing climate change, being indicators of climate change, to beginning to drive climate change, and the risks of those dynamics beginning to overwhelm anthropogenic impacts on these particular areas is growing as the amount of carbon dioxide in the atmosphere goes up, as the temperature rises.”
Clilmate factor permafrost
This applies in particular to the effect of thawing permafrost. Susan Natali from the US Woods Hole Research Centre is co-author of a landmark study published in Nature in April. She also joined the ICCI event in Bonn:
“Carbon has been accumulating in permafrost for tens of thousands of years. The amount of carbon currently stored in permafrost is about twice as much as in the atmosphere. So our current estimate is 1500 billion tons of carbon permanently frozen and locked away in permafrost. So you can imagine, as that permafrost thaws and even a portion of that gets released into the atmosphere, that this may lead to a significant increase in global greenhouse gas emissions.”
The study was conducted by an international permafrost network. “The goal is to put our current understanding of the processes in permafrost regions into global climate models. The current IPCC reports don’t include greenhouse gas emissions as a result of permafrost thaw”, says Natali.
Permafrost regions make up some 25% of the northern hemisphere land area. The scientists say between 30 and 70 percent of it could be lost by 2100, depending on the amount of temperature rise. There is still a lot of uncertainty over how much carbon could be released, but Winckelmann and her colleagues think thawing permafrost could release as much carbon into the atmosphere by 2100 as the USA, the world’s second biggest emitter, is currently emitting.
The time for action is now
“The thing to keep in mind is that the action we take now in terms of our fossil fuel emissions is going to have a significant impact on how much permafrost is lost and in turn how much carbon is released from permafrost. There is some uncertainty, but we know permafrost carbon losses will be substantial, they will be irreversible on a human-relevant time frame, and these emissions of ghgs from permafrost need to be accounted for if we want to meet our global emissions targets”, says Winckelmann.
The challenge is to convince politicians today to act now, in the interests of the future. Pam Pearson and her colleagues are working to have a synthesis of what scientists have found to date accessible to and understandable for the negotiators who will be at COP21 in Paris in December.
In terms of an outcome, she says first of all we need higher ambition now, in the pledges being made by different countries. The lower the temperature rise, the less the risk of further dynamic change processes being set off in the cryosphere. The other key factor is to make sure there is flexibility to up the targets on a regular basis, without being tied to a long negotiating process. The current agreement draft envisages five year reviews.
“There are a number of cryosphere scientists who actually expect these kinds of signals from cryosphere to multiply, and that there may be some dramatic developments just over the next three to five years, that may finally spur some action”, Pearson says.
Here’s hoping the UN negotiators will not wait for further catastrophic evidence before committing to an effective new climate treaty at the end of this year.
Further reading from my coverage:
DateJuly 7, 2015 | 2:43 pm