Tag: glaciers

In the Shadow of Melting Glaciers

CareyGlaciers

Adapting to climate change is a complex matter for human communities, as Mark Carey makes abundantly clear in his newly published book In the Shadow of Melting Glaciers: Climate Change and Andean Society. Carey is a historian and explores nearly sixty years of disaster response in Peru since the beginning of his story in 1941 when an outburst flood from a glacier lake in the Cordillera Blanca mountain range sent a massive wave of destruction on the city of Huarez, obliterating a third of the city and killing an estimated 5000 people.

There have been further disasters since that one.  Peruvians have, Carey points out, suffered the wrath of melting glaciers like no other society on earth.  Further outburst floods followed in 1945 and 1950, and glacier avalanches in 1962 and 1970 (the latter following an earthquake) killed many thousands.

The Huarez disaster prompted three national government strategies to protect the population from the hazards that the outburst flood had revealed: drain glacial lakes, prohibit urban reconstruction in the flood plain, and build retaining walls in Huarez to contain the glacier-fed Quilcay River. It all sounds quite rational. But only the first was able to proceed. Class and race issues, as Carey sees it, prevailed to counter the plans for hazard zoning and retaining walls. Huarez’s upper and middle classes wished to reconstruct the city in order to re-create the physical characteristics that helped symbolize urban authority and social standing in relation to the rural indigenous population. The socioeconomic order disrupted by the flood was to be restored.  Resistance to hazard zoning and relocation was not confined to Huarez but also occurred in other communities subsequently affected by disastrous outburst floods or glacier avalanches. One local writer reflecting on the triumph of “human will” which led to rebuilding in the same places of destruction concluded: “…[T]hey will be there forever, suffering. stoic, crying through their destiny. And that is the beauty of it, the poetry, the immortality of a people.” Defiant stuff, and part of the complexity Carey’s book explores.

But though people may have been unwilling to move from where they lived, they certainly supported the draining of glacial lakes and other measures to protect them from further disasters. Not that such measures are simple. Peru struggled to get a picture of the extent of the threat from glacial lakes in the Cordillera Blanca.  Indeed it was not until 1953 that an inventory of how many such lakes there were was finally achieved. There were 223. Today there are more than 400. It’s a growing problem. Once identified, lakes need to be assessed for the danger they pose. This is no easy matter. Accessibility is difficult.  The moraines behind which the lakes build vary greatly in their capacity to retain increasing volumes of meltwater. The incline of the glacier and the likelihood of large falls of ice causing large waves has to be taken into account. When drainage is undertaken the logistics of the operation can be daunting for both machinery and manpower.  Carey describes some of the on-site work as well as the difficulties at the national level of offices trying to carry out the task with limited resources and varying levels of support from successive governments.

Hydroelectricity is a complicating factor in the situation. The Santa River flows north through the valley parallel to the Cordillera Blanca. When it turns west and descends steeply to the coastal plain it feeds the large Cañón del Pato hydro-electric facility. The power station was itself the victim of the 1950 outburst flood, which destroyed it when it was nearing completion. It was the flood’s devastation of this facility and of the Chimbote-Huallanca railway line which transformed the piecemeal disaster prevention measures of the 1940s into the more effective and far-reaching response of a new government agency, the Lakes Commission. Carey notes that it was the setback to national industrialisation plans in 1950 rather than the deaths of thousands in the 1940s which led to this much better resourced body. The hydro-electric power station was rebuilt and, following privatisation in 1996 under Fujimori’s neoliberal progammes, is now owned by Duke Energy. Its generating capacity has increased considerably with successive upgrading.

Glaciers are not only hazards but also resources and Carey records a shift in emphasis after the 1980s from the hazard focus to the measurement and management of glaciers as hydrological resources, particularly for electricity generation and for irrigation. He notes that the information gathered has been of benefit to Duke Energy, a private company based in the US and responsible to shareholders rather than the Peruvian public. Duke Energy has been involved in attempts to retain glacial lake waters as reservoirs for regulating the flow of the Santa River and has encountered considerable local resistance. While glacier retreat has enabled expansion of water use in the region, this is a trend which is likely to change if the glaciers continue to diminish.

Hazards haven’t gone away because of the focus on resource, but the neoliberal agenda of the 1990s brought a severe reduction in the public funding of disaster prevention programmes. Neoliberalism exacerbated vulnerability to natural hazards, and although the state disaster prevention agency reopened in 2001 it never regained the status, budget and support it had in previous periods. Carey is even-handed in his treatment of neoliberalism, but sees it as a theory which collided with historical reality. Some of that reality is manifest in the local resistance which has prevented Duke Energy from managing the waterscape uncontested.

Throughout the book Carey devotes much attention to the ways in which various groups in Peruvian society and the relationships between them have played a part in forming the country’s response to melting glaciers. Many interests have had to be — sometimes have insisted on being — consulted and taken into account. Socio-economic divisions have played a part. Increasing international interest has become part of the interaction. Carey the historian has brought a valuable insight into the way a society functions or malfunctions in facing up to the impacts of climate change. He emphasises the need for understanding social relations and power dynamics at the same time as deciphering how much water will flow from a glacier in fifteen years’ time.

As Carey recognises, the acceleration of glacier melt is an issue not just for Peru but worldwide. Bolivia, Ecuador, Colombia, Nepal, India, Russia, Switzerland, the US and scores of other countries have populations which live near or depend on water from melting mountain glaciers. If there is a message to others from the Peruvian experience it is that disaster mitigation is a political and social process as much as it is a matter of science and engineering. Social conflicts, for example, may be more urgent to people than the potential floods or even water-shortage issues that experts see as the most pressing. It’s not only technical and scientific skills that will be needed but also a sense of social relations and of the perceptions of the populations affected.

As history Casey’s book is an engrossing read. What he recounts hardly leaves one sanguine about the ability of societies to navigate the adaptation requirements ahead as climate change begins to bite, but it offers some useful signposts.

[More at: Fishpond (NZ), Amazon.com (US), Book Depository (UK)]

Down to the sea

An interview with climatologist Ellen Mosley-Thompson published yesterday in Yale Environment 360is a reminder that for those working with ice there’s not much doubt about where we’re heading. She spent six weeks of the summer on her ninth visit to Antarctica drilling ice cores on the Antarctic Peninsula, one of the fastest-warming places on earth. Its winter temperatures have increased by 6 degrees over the past 60 years and year-round temperatures by 2.8 degrees. As a result, sea ice now covers the western Antarctic Peninsula three months less a year than three decades ago, 90 percent of glaciers along the western Antarctic Peninsula are in retreat, and large floating ice shelves are crumbling.

 

Mosley-Thompson headed a team of six for the drilling, and they were part of a larger group attempting to understand the warming behind the break-up of the Larsen B ice shelf in 2002. Ecologists were looking at an ecosystem on the ocean bottom that until eight or nine years ago had been covered by ice for thousands of years and considering how it is adjusting to the new normal. Glaciologists were looking at how much more rapidly the glaciers are discharging into the ocean with the disappearance of the buttressing ice shelf. A marine group was looking at changes in marine geo-chemistry, collecting new cores in the area that was covered by ice to compare with the cores previously drilled in the ocean bottom along the outer margins of Larsen B when it was in place.

It’s an impressive range of investigation she describes. The ice drilling on the Bruce Plateau was able to get right down to bedrock at 455 metres, and the cores will be closely analyzed back in Ohio for the information they contain about past climate, perhaps to the last glacial period and beyond.

Mosley-Thompson is married to Lonnie Thompson, the highly respected glaciologist. While his wife has been working mostly in Greenland and Antarctica he has done more ice corings of low-latitude glaciers –- in the Andes, Africa, and the Himalayas –- than any other person alive. Yale Environment comments that their work, taken together, paints a sobering portrait of the rapid retreat of most of the world’s glaciers and ice caps in the face of the buildup of planet-warming greenhouse gases.

Here are some of the things Mosley-Thompson has to say in the interview about the overall global picture. In response to the interviewer’s observation that the deep Antarctic ice cores taken at Dome C years show that we have got more CO2 in our atmosphere than at any time in 800,000 years:

“Very clearly. If you look back over the eight glacial/interglacial cycles, you essentially see that CO2 never rises above 300 parts per million and we’re at about 389 now. Methane never rises above about 800 parts per billion, and I think we’re at about 1,700 parts per billion. So we’re clearly outside the range of natural variability. I personally think that graph simply showing the natural fluctuations in those two important greenhouse gases, over almost a million years of Earth history — and then you see the two dots [today] that are so much higher than anything that we see in that near-million history — tells us very clearly that we have a serious problem.”

What does the cumulative ice coring  work show about what we’re experiencing in the last century or so in terms of the warming of the planet?

“ Well, from the tropical work, the cores in the Andes and the Himalaya, the oxygen isotopic ratio in those cores, when you stack those cores together, show very clearly that the last 50 or 60 years have been the warmest in the last 2,000 years.”

The ice cores from the Andes do show a Medieval Warm Period signature and a very distinct Little Ice Age cool signature.  Not surprising, she says, because both those periods are expressed most strongly around the Atlantic Basin and the moisture that builds the glaciers in the Andes of Peru actually comes from the Atlantic.  But the cores from the Tibetan Himalaya show virtually no signature of these periods.

“so when we put these records together, the medieval warming is very modest and the Little Ice Age signature is strongly muted as well. And what really stands out when you put these all together and into the composite, is the last 60 years. The oxygen isotopic enrichment in the tops of the cores [indicating warming] is very striking.”

She notes that particularly in the case of the tropical ice fields the glaciers are retreating very rapidly:

“And, in fact, several of the ice fields, particularly one that we recently published the results [for] in the southwestern Himalaya, it has not gained mass or has no ice that was deposited after 1950. It’s like these glaciers are just literally being decapitated. And it’s very frightening.”

And what about the IPCC error on Himalayan melting?

“…when you look at the breadth of the Intergovernmental Panel on Climate Change reports, and how much information is in there, the fact that this must be the most egregious error, otherwise they would be making more of something else –  I think it’s astounding that the IPCC got as much right as they did because there was just tremendous potential for error.”

And if we don’t begin to rein in CO2 emissions, where is the cryosphere, the Earth’s ice zone, heading?

“To the oceans. Ultimately that’s where all water goes, to the lowest level.”

Herald censures IPCC on flimsy grounds

In the current open journalistic season on IPCC sniping the NZ Herald has joined in with an editorial taking up new accusations made by the UK’s Sunday Telegraph and Sunday Times.

The editorial begins with the Himalayan glacier error, which the IPCC itself has accepted and expressed regret for.  But the Herald has the scent of blood and moves on to take up the claims of the UK newspapers with uncritical enthusiasm.

“If the Himalayan debacle was bad enough, the panel references to disappearing ice in the Andes, the European Alps and Africa are even more embarrassing.

They turn out to have been based on a student dissertation and an article in a climbing magazine.”

This absurd accusation probably originates with a Sunday Telegraph article, though it is not cited. Let’s look at what is involved.  In chapter 1 of Working Group II’s report there is a section on observed changes in the cryosphere.  In the course of the section a short table (page 86) of selected observed effects is provided. Included among them is the loss of ice climbs in the Andes, the Alps and Africa. It is in relation to this minor observation that the student dissertation and climbing magazine article are cited by the IPCC. But somehow the Herald manages to imply that the IPPCC references to disappearing ice are based on these two sources.

The reality is that the Working Group I report in chapter 4 (pages 356-360)  deals with observed changes glaciers in a section densely packed with scientific information, whereas the Working Group II report in which this report is found describes the observed effects on the environment and on human activities due to these recent cryospheric changes. And the loss of ice climbs is a tiny part of those effects.

But, says the Herald, the articles fall some way short of scientific evidence.  Admittedly they are anecdotal, but I imagine the IPCC authors regarded that as not unreasonable in a matter more likely to be noticed by climbers than researched in scientific papers. The author of one of the articles commented: “I am surprised that they have cited an article from a climbing magazine, but there is no reason why anecdotal evidence from climbers should be disregarded as they are spending a great deal of time in places that other people rarely go and so notice the changes.” Worth noting too that the magazine article was written by Mark Bowen, a keen climber and author of Thin Ice, the excellent story of Lonnie Thompson’s efforts to drill cores in high altitude tropical glaciers. Bowen went with Thompson on a number of expeditions, so knows his stuff.  IPCC authors are not, as is commonly thought, entirely restricted to peer-reviewed literature. Their instructions include the following:

“The authors will work on the basis of peer reviewed and internationally available literature, including manuscripts that can be made available for IPCC review and selected non-peer reviewed literature. Source, quality and validity of non-peer reviewed literature, such as private sector information need to be critically assessed by the authors and copies will have to be made available to reviewers who request them. Disparate views for which there is significant scientific or technical support should be clearly identified in IPCC reports, together with relevant arguments. Expert meetings and workshops may be used to support the preparation of a report.”

Maybe their judgement can be faulted in this particular case. Not by me, I hasten to say. But it is hardly a matter of any great substance. Indeed it is tiny. The Herald editorial grossly exaggerates its significance.

And there is more, says the Herald. There has been a critical examination of the IPCC’s ”attempts to link natural disasters to global warming”.  The Herald doesn’t mention that this ”critical examination” was conducted by the UK Sunday Times.

“ [The IPCC’s] claim in 2007 that the world had ‘suffered rapidly rising costs due to extreme weather-related events since the 1970s’ turns out to have been based on a paper that had not been peer-reviewed or published at that time.”

The words in quotes look as if they are from the IPCC report.  They’re not.  They’re from the Sunday Times article. The IPCC report is restrained and cautious. The Sunday Times article is sloppy and wildly inaccurate.  You can read what I wrote about it on Hot Topic here.  I won’t repeat myself. I described it as simply untrue. But it has evidently entered the journalistic canon.

I guess we should be relieved that the Herald shows no inclination to join the denialist community as a result of its uncritical acceptance of the Sunday Telegraph and Sunday Times articles, but it should think again about the strictures which it was lavish with.  The IPCC reports are massive in size and massive in value.  It may be asking a bit much that editorial writers should spend time acquainting themselves with them, but if they are not going to do that they should at least treat with great caution the ”revelations” of its failures in scientific rigour. There will no doubt be more of those, since I suspect the denialist community is going through the IPCC references with a fine comb. If they prove correct the IPCC will again acknowledge error and express regret, as it did over the Himalayan glaciers. But the Herald should make sure it is dealing with matters of reasonable substance before it rushes to judgement.

More than a metre

Sea level will rise by more than a metre by 2100 according to the authors of the third chapter in the World Wide Fund for Nature’s new Arctic report, introduced by Gareth a few days ago. Eric Rignot, one of the two authors of the chapter, is principal scientist for the Radar Science and Engineering Section at NASA’s Jet Propulsion Laboratory, Pasadena, Calif.  The other author, Anny Cazenave, is an internationally renowned research scientist from France’s national centre for space studies.

The value of the chapter is that it draws together, authoritatively and coherently, the evidence that points to considerably more sea-level rise over this century than projected in the 2007 IPCC Fourth Report (AR4). Happily politicians are taking IPCC reports much more seriously than in the past, but they should not rest on them.  Their responsibility is to be up to date with what the science is saying now. The WWF report assesses the most recent science, and finds that the impacts of warming will be more severe than indicated by the IPCC.

What follows is a summary of the main points made by the chapter.

Continue reading “More than a metre”

The PIG is flying

PIGmap.gif The Pine Island Glacier in West Antarctica is thinning four times faster than 10 years ago, a new study(*) of satellite measurements shows. Since 1994, the central portion of the glacier has thinned by as much as 90 metres, and the ice surface is currently lowering by 16 metres a year. At this rate of thinning, the glacier could disappear in 100 years, instead of the 600 years earlier estimates had suggested. The BBC report includes an excellent video, and focuses on the implications for sea level rise:

One of the authors, Professor Andrew Shepherd of Leeds University, said that the melting from the centre of the glacier would add about 3cm to global sea level.
“But the ice trapped behind it is about 20-30cm of sea level rise and as soon as we destabilise or remove the middle of the glacier we don’t know really know what’s going to happen to the ice behind it,” he told BBC News. “This is unprecedented in this area of Antarctica. We’ve known that it’s been out of balance for some time, but nothing in the natural world is lost at an accelerating exponential rate like this glacier.”

Unlike Greenland, where surface melting adds to losses caused by warming oceans, in West Antarctica it’s thought that warm ocean currents (specifically the Upper Circumpolar Deep Water, which is 3ºC warmer than surface water in the region) are being channelled in under the PIG ice shelf, helped by the large trough the glacier carved in the sea floor during previous glacial maxima. Given concerns about the stability of the West Antarctic ice sheet as the world warms and sea level rises, the words “exponential rate” sound particularly ominous…


(*) Wingham, D.J., D.W. Wallis, and A. Shepherd (2009), Spatial and temporal evolution of Pine Island Glacier thinning, 1995-2006, Geophys. Res. Lett., doi:10.1029/2009GL039126, in press.