Hot and hungry in the Andes
“When I was a child there was such an abundance of water…” says Santiago Quispe, the community leader of San Luis, a remote village in the Peruvian high Andes. I can hardly hear him at the top of the mountain as the wind risks blowing his leather hat, and his words, down the golden valley that unfolds below. At about 13,000 ft and with no electricity or running water, the only sources of income for San Luis’ 24 families are agriculture and ranching. Very little grows at this altitude and with no irrigation it is mostly potatoes and quinua that can be harvested locally during the short wet season. Most of the income, and food for consumption, comes from cattle, sheep and alpaca ranching. For Santiago 13,000 ft is ‘lowland’, where the most profitable commodity, cows, can actually survive. But the ‘lowland’ is only a narrow strip surrounded by steep mountain sides where most of the grazing must happen and where only alpacas can survive.
“I can sell one liter of milk for about 80 cents [of a Sol – equivalent to about 25 US cents], you know, according to the market fluctuations. Now my cows produce not more than 11 liters a day. With the same number of cows, I remember before, we would produce 25 liters.” Most of Santiago’s milk is sold to local cheese producers who pay him $2.75 for his total of 11 daily liters. This is his primary source of income, with the occasional sale of a lamb or alpaca assisting to cover transport and food costs. But most of the alpaca is used for his own consumption. Needing to support the three members of his family, that puts him at about the $1 per day poverty level.
This is representative for not only the town of San Luis, but the life of thousands of poor farmers living in the Andes, and the trends extend worldwide. A recent study by Dr. Samuel Myers from Harvard Medical school shows how in certain parts of the world water scarcity has “prevented yields from rising over the past 35 years, and in some areas, they have been falling”. Many of the affected are already poor people who have the least resources to adapt to changes and run the risk of going from poverty to hunger. The links between environmental degradation and human health are widely known, and already “roughly 16% of the global burden of disease is attributable to childhood malnutrition”. With an inadequate diet, people and especially children, are more susceptible to a wide variety of diseases and illnesses. Santiago hasn’t ready any of these studies, but he is well aware of the danger that looms ahead if the availability of water doesn’t improve.
Santiago lives in the Ayaviri district along with (population) other residents, 42% of whom are dedicated to agriculture (mostly potatoes) and another 58% towards cattle and alpaca ranching. There is almost no commerce or industry which makes the population particularly susceptible to climatic changes. For such an impoverished and vulnerable population the consequences of water shortage trends can de disastrous. When I ask Santiago what he thinks is causing falling production levels he smiles, as if putting together a happy memory and points to the brown mountain tops around us, “when I was a child all these were white… like that one.” I look to where his finger points and it takes me to the one visible remaining glacier, Kunurana, on the other side of the valley. At 19,292 ft this massive giant glows white under the tirelessly blazing sun of the dry season.
Over the years I have heard the same stories from local villagers across the Andes. The older the person is, the more emphatic they seem to stress the contrast between the white capped mountains of before and the barren summits of today. For all that anecdotal evidence is worth, over the years I have spent visiting this region I have noticed the Kunurana glacier retreat, or at least that is my impression. Last year I embarked on a grueling hike to reach the glacier that gives rise to the Vilcanota, one of Peru’s most important rivers. I wanted to go because I worried it would not be there if I waited any longer. At about the threshold of 5500 m (18,150 ft), with a constantly thumping headache, I reached the glacier, proud and sad to encounter a reality that I fear may not be around for very long.
Science has been showing that Santiago’s and my fears and intuitions are not far from reality. Given the extensive and heated debate on climate change, the recent trend in glaciology has focused increasingly on glaciers that lie within the tropics because they are “the most visible indicator of climate change, due to their fast response time, their sensitivity to climate variations and the clear visibility”, as indicated by Dr. Vuille, a tropical glaciology expert. Towering above the coastal desert on one side and the Amazon jungle on the other, the Andes contain almost all (99%) of all the world’s tropical glaciers, and in Peru alone accounts for 70% of these. Tropical glaciers are especially sensitive to climate change because they are usually closest to the threshold temperature that keeps the glacier from melting. A small increase in temperature and the glacier may disappear within centuries if not decades. This is what happened in Venezuela where “they have lost more than 95% of their glacier-covered area since the mid-19th century”. My fears of not seeing the Kunurana glacier in the future may not be so far from reality.
In fact, several studies show that “strong glacier retreat has been occurring at all basins in recent decades, mainly in response to atmospheric warming” (Casassa, 2008). Recent studies have shown how these tropical glaciers reached their maximum extent between 1630 and 1680 AD and have seen a significant recession since the middle of the 19th century (Viulle et al, 2008). A detailed study of five Cordillera Blanca glaciers, north of San Luis, shows rapid glacier retreat in the 1980’s and a slowing in the late 90’s where in the “last few years the retreat seems to again have gained momentum”. The most dramatic example is the specific survey of the Chacaltaya glacier in neighboring Bolivia, which has lost 62% of its mass between 1940 and 1983. As researcher Edson Ramirez and colleagues from the IRD in France state the glacier lost 40% of its thickness in only six years from 1992 to 1998. Not all glaciers are retreating so rapidly, but these measurements are emblematic of a trend for small glaciers and their futures.
The theory that explains the rapid decrease of glaciers can be explained by “edge effects”. In the words of the researchers themselves: “Chacaltaya is a very small and low-lying glacier, and therefore particularly vulnerable to climate change. The retreat of such small glaciers is accelerated once they reach a critical size, below which ‘edge effects’ become important. At the edge of tropical glaciers air temperature above surrounding rocks can exceed 20 °C at daytime.” This is important because as tropical glaciers reach their critical size, the rate of melting accelerates and they begin to disappear. While these statistics may not apply to most of the worlds glaciers (yet) and while glaciology studies are being ferociously debated since they serve as evidence for global warming, my interests are less ambitious and more personal.
As I stand with Santiago looking at Kunurana glacier I wonder if the critical size has already been reached. It is certainly a small glacier and only about 1000 ft higher than the sentenced Chacaltaya glacier in Bolivia. At this point I am not too concerned whether the melting is caused by natural solar variation or purely anthropogenic forces; no foreseeable means to avert either will be likely to help Santiago in his lifetime. Regardless of the causes, my interest is to help him and millions like him adapt to the consequences of what we see happening before our eyes.
Indeed, while “warming in the tropical Andes is likely to be of similar magnitude as in the Arctic,” researchers caution that the warming will come “with consequences that may be felt much sooner and which will affect a much larger population”. Public attention is beginning to shift towards a greater concern for how people will be affected in these regions. The effects of these tropical glaciers on people are certainly disproportionate to their size, being “a major water resource for Andean communities, even if they represent only 0.15% of global ice cover”. One of the reasons glacial water is so important is because rainfall is so seasonal. During the dry season, from April to November, every single day shows a bright blue sky and a relentless sun. During the wet months just about every day sees rainfall. The glaciers provide a critical buffer against the highly seasonal precipitation at times where water for domestic and agriculture in the form of rainfall is completely absent. Furthermore, what is true for San Luis is true in other arid and semiarid regions of the tropics and subtropics where “more than 80% of the freshwater supply originates in mountain regions, affecting populations downstream”.
In Santiago’s case this is starkly true. At the heart of the dry season, his cattle need to walk longer distances through dry pasture to reach the valley which is fed from the river from the Kunurana glacier. The stream that flows through the village of San Luis is completely dry and only comes to life during the wet season. It submerges only to arise miles away from his home. The reason I met Santiago in the first place is that he contacted the local municipality on behalf of his village to consider building a small damn to keep the water that is precipitated in the wet season. The engineer that accompanies them tells me that he has received similar requests from hundreds of people and that as the only employed engineer it is impossible for him to provide these services on his municipal salary. He thinks that the situation is going to get worse.
While the glaciers are still existent there is discharge and perhaps even more water supply due to accelerated melting. This may lead to an artificial sense of water abundance, but if the glaciers experience a net mass decrease, they will reach a point where there will be no source of water whatsoever. This is confirmed by several studies that glaciologists are currently debating. Prof. Pouyaud, the foremost expert on Peruvian glaciology, has demonstrated how many high altitude glaciers in Peru, and others around the world, are showing increased discharge over the last decades. According to Pouyaud, some glaciers may exhibit an increase in discharge until about 2050, at which point a critical level would be reached due to severe wastage and discharge decreases. The smallest of the studied glaciers is predicted to disappear by 2175 and the largest glacier in Peru, Llanganuco, expected to disappear by 2250. Other scientists claim Pouyaud’s theory must be taken with caution since it may only be relevant to this specific region. Whether the exact predictions of glacier disappearance are accurate or not the answer lies somewhere in the future, but the impacts of melting are being felt right now.
Most experts are in agreement that glacier melt is fundamentally important for water supplies to downstream populations. Sophisticated hydro chemical studies allow scientists to identify how much of the water in a stream has its source from glaciers. A study by Dr. Bryan Mark, from the Institute for Biogeochemistry in Germany, conducted on the Rio Santa in Peru shows that glacier melt contributes an estimated 35% of the average discharge. The study also concludes that with the continued glacier recession is likely to decrease and become more variable, precisely as Santiago had observed himself. His complaints that the rivers in the wet season were fuller and dryer in the dry season are demonstrated by the latest scientific studies. They even conclude with policy alternatives that include preparation for water scarcity such as reservoirs. I have some comfort that Santiago is figuring out what the worlds leading scientists have taken decades to confirm.
But Santiago’s concerns are not limited glaciers and the glaciologists who study them. Santiago sees water scarcity threatened by another source: the sky. Along with the important supply of water from glaciers, much of the negative effects on ranching and agricultural production are due to the shorter wet season. The grass contains less moisture and nutrients and the cows produce less milk. The days are hotter and the nights are colder he says, further stressing the thirsty animals. We walk towards a narrow gulch which holds one of the few forests in the area. We must get permission from the neighbor who guards the entrance and keeps one of the regions most prized resources: wood. According to Santiago in the 90’s under now ousted President Fujimori, several projects were implemented to reforest the barren altiplano. Due to incompetence, lack of expertise and corruption, the only survivor seems to be this humble stand of trees about the size of an Olympic swimming pool. The trees enclosed in this alcove create a minimal micro-climate as is announced by the unique chirping of birds among the tree fruits. Santiago bends over and shows me a tuft of grass, which is green about half way up and compares to the practically brown sample from the open field. Pointing to the greener sample he says, “this is how the grass used to be in the past”.
If the history and future of tropical glaciers is somewhat illusive and only recently being unveiled, this is much more the case with regards to temperature and precipitation. Particularly interested in the effects of glaciers, glaciologists have been quite keen in collecting temperature records in recent history. The information we do have is not promising for Santiago: temperatures are rising and according to the worst case scenarios presented by the IPCC by the end of the 21st century “the tropical Andes will experience a massive warming on the order of 4.5–5 °C. Analysis of changes in surface temperature show that tropical South America will warm more than the southern part of the continent”. It has been long known that warmer temperatures increase evapotranspiration in plants requiring more water for the same yields. With regards to precipitation “most models used for the IPCC-AR4 report predict an increase in precipitation in the tropical Andes during the wet season and a decrease during the dry season, effectively enhancing the seasonal hydrological cycle”. This would only augment what the glaciers would be doing already by enhancing the seasonal variability.
Recent debate has put into question the assumptions of the IPCC and their emphasis on carbon mitigation. But I am as uninterested as Santiago in the high minded scientific and political debates with regards to the sources of these changes and subsequent problems. Our immediate concern is about how people in poverty can cope with the changes in climate, regardless of the origin of those changes. Tragically, adaptation is most pressing for those least capable of it. To Santiago, it is not a question of mere discomfort or a loss of profits; it is a question of survival.
As we sit under the micro-forest he pulls out a cloth with tiny potatoes cooked traditionally under the earth, and shares with me a slice of cheese and a glass of milk. This humble and generous man works to survive and this is his meal for the day. This is the story of his parents and great grandparents, but he worries about the story of his children and their generation. The way things are going there may not be anyone left to tell the story. Therefore, rather than historical responsibility or geo-political guilt, which I am sure Santiago is willing to forgive, what unites Santiago, the glaciologists, me, and people all across the globe is not the past but the future. The solidarity that springs from our shared humanity has compelled me and countless others to assist those in need to adapt to the coming changes. Whether it be a small dam from the engineer, a donation by the businessman, a prayer of hope from the devout, research by the scientist or a funding plan by the business major we should all do our part.
For Santiago’s sake, we must.
- Myers, Samuel et al. Emerging Threats to Human Health from Global Environmental Change. Annu. Rev. Environ. Resour. 2009. 34:223–52
- Vuille, Matias et al. Climate change and tropical Andean glaciers: Past, present and future. Earth-Science Reviews 89 (2008) 79–96, 24 April 2008.
- Mark, Bryan G. et al. Tropical glacier meltwater contribution to stream discharge: a case study in the Cordillera Blanca, Peru. Journal of Glaciology , Vol. 49, No.165, 2003.
- Cassasa, Gino and Pouyaud, Bernard et al. Detection of changes in glacial run-off in alpine basins: examples from North America, the Alps, central Asia and the Andes. Hydrol. Process. 23, 31–41 (2009)
- Jomelli, Vincent et al. Fluctuations of glaciers in the tropical Andes over the last millennium and palaeoclimatic implications: A review “Palaeogeography, Palaeoclimatology, Palaeoecology 281 (2009) 269–282. 9 April 2009