Tag: climate change

• Curious Bends – outraged warriors, bizarre obsessions, dubious drugs and more

  It’s been one year since we launched Curious Bends – a newsletter where we bring you science, technology, data and India stories from around the web, once a week (subscribe).

  We’ve enjoyed serving you important and interesting stories. Thank you for being loyal subscribers!

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  Starting this week, the newsletter has a new home at The Wire.

  1. India’s bizarre, fascinating and occasionally horrifying obsession with urine

  “Urine is one of those perennially surfacing topics in Indian media and it is difficult for a year to go by without multiple references to urine, whether of humans, cows, rhinos, tigers or elephants, of the diseased or undiseased kind, medical therapies, recipes for consumption and more. As a nation, we are obsessed.” (6 min read, scroll.in)

  2. India has more illiterates than anywhere in the world—partly because of a preference for sons

  “An extra child—which is likely had to have a trophy son—in the family reduces schooling, on average, by 0.1 years. Furthermore, that extra child reduces the probability of ever attending or being enrolled in school by up to 2%. Both numbers may seem small, but for the size of India’s young population, the upshot is that millions don’t go to school enough or at all.” (3 min read, qz.com)

  3. Why Indians aren’t outraged about climate change

  “Astonishingly, the intensification of political activity has not led to a wider engagement with what is self-evidently the single greatest threat that humanity has ever faced: climate change. This is understandably a matter of despair for the activists and scientists who have been battling to warn the world about what lies ahead. Their mounting anguish and frustration at the world’s continuing indifference is itself an instructive commentary on our institutions and the myths they are built upon. Many scientists and activists have gone from combativeness to rage and then to a quiet resignation in the face of what they now believe to be an inescapable catastrophe – or rather a series of catastrophes which will consume tens, if not hundreds, of millions of lives.” (6 min read, thewire.in)

  + The author, Amitav Ghosh, is a celebrated Indian writer whose work in English fiction has been shortlisted for the Man Booker Prize.

  4. World Health Statistics 2015: some achievements, many concerns

  “The World Health Organization (WHO), on Wednesday, released this year’s World Health Statistics (WHS) which evaluate achievements in health with respect to targets set as part of the MDGs. While WHS lists some landmark accomplishments reported in the 15 years since the beginning of the global programme, the overall results have been a mixed bag with great variations between regions and countries.” (7 min read, downtoearth.org.in)

  5. Most antidepressant drug combos in India are unapproved

  “The health of 120 million patients in India is in jeopardy because of the proliferation in the past decade of unapproved and unregulated combination drugs commonly used as anti-inflammatory, antidepressant and anti-psychotic medication, a new study has found. The research findings are especially troubling for people who are depressed because 8-in-10 antidepressant and 7-in-10 anti-psychotic combination drugs in India don’t have the proper approval. Worldwide, depression has already taken over as the leading cause of disability but its treatment in India is largely unregulated.” (4 min read, thewire.in)

  Chart of the Week

  In the past year, Curious Bends has shared a total of 212 stories with you from 69 different sources. Of course, our selection is biased because of the places we read most. However, our effort to spread the net broad has showed us that the state of science journalism for India-related stories is not nearly as poor as we had thought going in. The problem is that, while there are a lot of sources that publish good stories that fit our criteria, they don’t do it consistently enough. That’s why we find curating these good stories worth our effort, and it is reinforced by the fact that so many people have subscribed to this newsletter.

  

  2015.05.25

• As seas exchange heat, the Indian Ocean is becoming a marine hothouse

  The Wire
  May 21, 2015

  Since about 1998, the rate at which the Earth’s surface temperature has been becoming hotter due to anthropogenic global warming has slowed. It slipped from about 0.12 kelvin per decade since the late 1800s to about 0.05 kelvin per decade. For a time, climate deniers jumped on this statistic to refute that the burning of fossil fuels was warming the planet. However, scientists found out that such variations were due to the internal variability of the world’s climate, and that such hiatuses would occur again.

  In fact, during the hiatus period the subsurface Pacific Ocean was found to have absorbed a significant amount of heat. But recent measurements of the sea’s depths have actually signalled that the temperature there is dropping, not increasing. If the Pacific Ocean had absorbed the heat from Earth’s atmosphere yet its subsurface waters were cooling, where is the heat?

  As it turns out, the Pacific has been leaking it into the Indian Ocean for the last decade, via currents running along the Indonesian archipelago. A team of researchers from France and the US found that the upper 700 m of the Indian Ocean accounted for more than 70% of the global heat gain in 2003-2012.

  “The model simulation and hydrographic data both showed that Indian Ocean heat content did not increase much prior to 2000,” said Sang-Ki Lee, an oceanographer at the National Oceanic and Atmospheric Administration, and lead author of the study. “We believe that the massive heat transport from the Pacific Ocean to the Indian Ocean occurred during the past decade is a fairly unusual phenomenon.” They published their findings in Nature Geoscience on May 19.

  To support the measurements they made, Lee and his team simulated the warm water’s flow from the Pacific into the Indian Ocean in a computer program. “It is not clear how good the model is in simulating the features of the Indian Ocean, specially at subsurface levels,” P.N. Vinayachandran, associate professor at the Centre for Atmospheric and Oceanic Sciences at the Indian Institute of Science, Bengaluru, told The Wire. “The reliability of results would depend on this factor.”

  Nonetheless, the hydrographic data mustered by Lee and co. and their model’s ability fit in seamlessly with the onset of the hiatus in 1998 lends a platform from which to explore the consequences of their find. According to their model, the warm water was transported into the Indian Ocean through the Indonesian Throughflow. It is a series of deep straits in the archipelago through which, due to a pressure gradient between the two oceans, 15 million cubic metres of warm water flowed per year.

  The resultant cooling of the Pacific is likely to influence the El Nino southern oscillation, an anomalous heating and cooling of the Pacific’s waters off the tropical South American coast. Normally, they are about eight degrees Celsius cooler than the waters along eastern Indonesia. However, during years in which the trade winds blowing from South America to Australia and Indonesia fall off, the water along the coast of Peru becomes warmer. The result is floods in Peru and droughts in Australia and Indonesia.

  The study’s authors state that the heat being pumped into the Indian from the Pacific Ocean was driven by a converse event – of the waters having becoming warmer off the coast of eastern Indonesia. Warm waters are typically nutrient-deficient and don’t support fisheries. They are also detrimental to marine ecosystems in general, greatly endangering creatures that can’t relocate to cooler waters quickly (such as coral reefs) and in turn other creatures dependent on them (like the orange-spotted filefish).

  Moreover, the study reconciles the Pacific and Indian Oceans’ warming trends while also emphasizing how little we know about heat absorption by the world’s oceanic basins despite their significant effects on climate. It also raises important questions about where and how the stored heat will be released and with what socioeconomic consequences.

  “It is possible that the upper ocean warmth in the Indian Ocean may be carried to the North Atlantic Ocean to increase the frequency and amplitude of Atlantic hurricanes and to accelerate the melting of Arctic sea-ice,” Lee said, but that would be on a much longer timescale.

  On shorter timelines, during the Indian summer monsoon, deeper, colder water rises to the surface along the Somalian, Arabian and western Indian coasts. Lee explained: “Due to the increased upper ocean warmth the upwelling may bring warmer water to the surface releasing more water vapour to the atmosphere and thus increasing the moisture transport to India and the Southeast Asia.” This would bring more rain – and possibly floods.

  Another possibility, which Lee says their team will next investigate, is the Indian Ocean transporting its heat into the Atlantic Ocean via the Agulhas current that bends around the coast of South Africa. This presents more devastating consequences because the Atlantic has already been on a warming trend since the 1950s.

  Finally, the oceans aren’t bottomless either. Once a threshold is reached, they will release the heat back into the atmosphere. A study in Nature Climate Change from February this year predicted the event would be like a burst, starting from around 2020, a sustained release that would be associated with “warming across South America, Australia, Africa and Southeast Asia.” The event will also accelerate the melting of ice in the Antarctic and lead to rising sea levels.

  Recent studies – including Sang-Ki Lee’s – present an important challenge. The global impact of climate change hasn’t yet visited humans the way it visited the golden toad (by wiping it out) and there is still talk by governments to reverse its impact. But with the warming hiatus predicted to end by 2020 and the Indian Ocean shown to be a prominent player in global climate variations, the world could receive a brutal preview of what life might be like at the end of this century in the next 10 years.

  2015.05.21

• The global warming hiatus could last another five years. Its aftermath is the real problem.

  Whether you’ve been fending off climate-change skeptics on Twitter or have been looking for reasons to become a climate-change skeptic yourself, you must’ve heard about the hiatus. It’s the name given to a relatively drastic drop in the rate at which the world’s surface temperatures have increased, starting since the late 1990s, as compared to the rate since the early 1900s. Even if different measurements have revealed different drops in the rate, there’s no doubt among those who believe in anthropogenic global-warming that it’s happening.

  According to one account: between 1998 and 2012, the global surface temperature rose by 0.05 kelvin per decade as opposed to 0.12 kelvin in the decades preceding it, going back to the start of the previous century. To be sure, the Earth has not stopped getting warmer, but the rate at which it was doing so got turned down a notch for reasons that weren’t immediately understood. And even as climate-scientists have been taking their readings, debate has surged about what the hiatus portends for the future of climate-change.

  Now, a new study in Nature Climate Change has taken a shot at settling just this debate. According to it: The chances that a global-warming hiatus will happen for 10 consecutive years is about 10%, but that it will happen for 20 consecutive years is less than 1%. Finally, it says, if a warming hiatus has lasted for 15 years, then the chances it will last for five more years could be as high as 25%. So that means the current letoff in warming is somewhat likely to go on till 2020.

  The study was published on February 23, titled pithily, Quantifying the likelihood of a continued hiatus in global warming. It focuses on the effects of internal variability, which – according to the IPCC – is the variability due to internal processes in the climate system (such as the El Niño Southern Oscillation) and excluding external influences (such as volcanic eruptions and sulphate aerosol emissions).

  At the least, the statistically deduced projections empower climate scientists by giving them a vantage point from which to address the slowdown in warming rates since the start of this century. But more significantly, the numbers and methods give observers – such as those in the government and policy-makers – a perspective with which to address a seeming anomaly that has come at a crucial time for tackling anthropogenic global warming.

  

  Its timing (as if it could be timed) was crucial because it coincided with the same decade in which most of the faster-growing economies on the planet were circling each other in the negotiation bullring, wanting to be perceived as being committed to protecting the environment while reluctant about backing down on growth-rate reforms. The slowdown was a not-insurmountable-yet-still-there stumbling block to effectively mobilizing public debate on the issue. Needless to say, it also made for fodder for the deniers.

  Wryly enough, the Nature Climate Change study shows that it is not an anomaly that’s about to let anybody off the hook but a phenomenon actually consistent with what we know about internal climate variability, and that such an event though rare could last two full decades without defying our knowledge. In fact, throw in coincident external variability and we have the additional possibility of longer and stronger hiatus periods in reality.

  Anyway, there is yet more cause for alarm with this assertion because it suggests that some natural entity – in this case the sub-surface Pacific Ocean – is absorbing heat and causing the hiatus. Once a threshold is reached, that accumulated heat will be released in a sustained burst of about five years. The study’s authors term this the period of ‘accelerated warming’, when the oceans release 0.2 W/m² of energy in “a pattern … that approximates a mirror image of surface temperature trends during hiatus periods”.

  The analysis was based on data obtained from the Coupled Carbon Cycle Climate Model Intercomparison Project (Phase 5), which assesses changes in the climate due to changes in the carbon cycle in the presence of external variables. And simulations using it helped the researchers highlight a worrying discrepancy from previous predictions for the Arctic region:

  Hiatus decades associated with internal variability in models generally exhibit cooling over the Arctic whereas recent observations indicate a strong warming. Our results indicate that, following the termination of the current global warming hiatus, internal climate variability may act to intensify rates of Arctic warming leading to increased climate stress on a region that is already particularly vulnerable to climate change.

  The Arctic isn’t the only region that’s in trouble. The authors also predict that the period of accelerated warming will be “associated with warming across South America, Australia, Africa and Southeast Asia”. This doesn’t bode well: developing nations have been found to be especially susceptible to the adverse effects of anthropogenic warming because of their dependence on agriculture and for being under-prepared for catastrophic weather events.

  Even if climate talks are beginning to focus on goals for the post-2020 period, this predicted asymmetry of impact won’t be at the top of negotiators’ minds at the 21st annual Conference of the Parties to the UNFCCC in Paris on November 30. However, should it transpire, the slowdown-speedup tendencies of climate variability could further muddle negotiations already fraught with shifting alliances and general bullheadedness.

  2015.02.23

• Better to have been a mammal in India

  The Copernican
  April 10, 2014

  Studies of fossils and soil samples collected at a site in South India have revealed unique attributes of the ecosystem not found in many parts of the world. In particular, an international team of scientists found that most mammalian species in the region seem to have survived at least 100,000 years in conditions that could have pushed them to extinction in Europe or the Americas.

  Their research, for the first time, reports on dated and stratified deposits of mammalian fauna in the Indian subcontinent over the last 200,000 years. In addition, “one of the most significant findings is that a variety of mammals survived through major fluctuations of climate in the past,” said Michael Petraglia, one of the authors of the study published in Proceedings of the National Academy of Sciences in the week of April 7.

  Apart from climactic changes, the Indian subcontinent was also subjected to the devastating Toba volcanic super-eruption 75,000 years ago as well as increasing numbers of humans in the last 10,000 years. Mammals in the subcontinent, however, survived almost unchanged because they had access to a unique range of ecosystems to inhabit. Meanwhile, those in many other parts of the world were becoming extinct in large numbers. The difference lay in the nature of their habitats.

  A mosaic

  The configuration of geographic landmarks and monsoon patterns “has given rise to a network of ecosystems like the coastal mangrove, evergreen upland western and eastern ghats, deciduous forest, semi-arid inland regions, the Thar desert and plains of the Indus and Ganga,” explained Dr. Ravi Korisettar. “Between the Vindhyas in the north and the Nilgiris in the south, the Deccan Plateau has preserved a variety of these ecosystems suitable for habitation since prehistoric times.”

  Dr. Korisettar is the Dr. D.C. Pavate Professor of Art and Archaeology, Karnatak University, Dharwad, and a member of the team that conducted the study.

  It found that the variety of ecological settings available for habitation as well as their interconnected nature were essential for the continued existence of mammals. “The mosaic of habitats allows for the presence of a diverse range of species, whereas the connection between these habitats allows animals to migrate between them as the climate changes,” said Dr. Petraglia, of the Research Laboratory for Archaeology and the History of Art, University of Oxford, UK.

  Their findings are consistent with fossil records from around South Asia, and with parts of tropical Africa.

  Both these scientists were part of a team that studied samples collected from the Billasurgam cave complex in the Kurnool district of Andhra Pradesh, a state in southern India. The site was chosen because investigations in the 1970s had found that many animal fossils and archaeological deposits were present there.

  Describing their findings, Dr. Korisettar said they’d found “11 families and 26 genera of birds, mammals and amphibians. There were antelopes, gazelles, horses, pigs, primates, rhinoceroses, rabbits, and evidence of crocodile amphibians.” The samples were then studied using optically stimulated luminescence to discern their ages and characteristics. With the exception of one primate – identified in the paper as Theropithecus cf gelada – all other mammalian taxa, or population groups, survive in the subcontinent to this day.

  Conservation efforts

  However, even as Dr. Korisettar remarks, “Conserve the habitats, the rest will take care of itself”, the quality of the mammals’ survival these days is deteriorating. One of the suggested causes for extinction of fauna in other parts of the world in the last 1,000 centuries was over-hunting by early humans. An analogous threat has come to modern India after all these years of resilient survival: anthropogenic climate change.

  Is a mutually beneficial coexistence possible once again?

  “Climate change, in combination with the dramatic increases in human populations in the last 10,000 years in India, may be leading to decline of certain animals, restricting them to smaller geographic ranges,” Dr. Petraglia said. For example, the Kaziranga National Park in northeast India hosts two thirds of the world’s population of Great One-horned Rhinoceroses, an animal whose habitat may once have spread farther south.

  But whatever has been pushing them over the brink, mammalian conservation efforts in India may now find it essential to not just preserve habitats but also their inter-connected nature in the subcontinent. Moreover, Dr. Petraglia suggested that the Billasurgam caves also be protected against economic development in the region, especially mining activities. “The caves should be considered for national protection owing to their fascinating history of research and the significance of their deposits for future research,” he said.

  2014.06.16

• All ice that falls is not an avalanche

  Note: Updated with quotes from Patrick Wagnon, ICIMOD

  On April 18, an avalanche on Mount Everest killed 16 Nepalese guides. By the end of the month, 13 bodies had been recovered. The search for the remaining three was called off after conditions were termed too risky and difficult. On April 22, the Sherpa guides announced they would not work on the mountain as a mark of respect for their fallen colleagues. The climbing season on Mt. Everest for 2014 was closed.

  The incident drew attention from around the world – as consternation aimed at the Nepalese government’s provision of insufficient compensation and as concern over the effects of climate change. Its capacity to be a rallying point for anthropogenic warming was bolstered after another avalanche on May 23 that killed one climber and two more guides, who were scaling Yalung Kang, a sister peak of Mt. Kanchenjunga.

  Except that the April-18 incident wasn’t an avalanche, according to some glaciologists, climate change specialists and other scientists from the International Centre for Integrated Mountain Development (ICIMOD), Nepal. They issued a ‘Clarification on  inaccurate media reports‘ on May 23, about a week after a conference on the Hindu Kush Himalayas cryosphere closed.

  They attributed the April-18 tragedy to a serac fall, and explained how it was different from an avalanche.

  “An avalanche requires a snowpack of sufficient depth with a weak layer, a sufficiently steep slope, and a trigger. In contrast, the 18 April tragedy on Mount Everest was the result of a different phenomenon called serac collapse. Seracs are large blocks of ice that are formed as a result of glacier fracture patterns and motion, and can fall or topple without warning.”

  Thus, most of the time, there is no relationship between climate change and avalanche/serac risk.

  Little to no link

  According to Patrick Wagnon, one of the authors of the media clarification and a glaciologist at ICIMOD, “Serac falls are due to glacier flow and fracturation, and glaciers move down with gravity. Avalanche are due to snow falls, slope, and snow cover stability, and gravity is the main process to trigger avalanches.”

  Going by the ICIMOD clarification, the April 18 avalanche that killed the 16 guides was triggered by a serac fall.

  In the same statement, the scientists add, “Changes in the frequency of either avalanches or serac falls in the Everest region have not been definitively linked to climate change.” So further studies have to be done to establish the nature of the link between climate change and the frequency and magnitude of avalanches and serac falls.

  Wagnon added, “As far as I know, no studies have been conducted so far to link climate change and serac falls or avalanches in the Himalayas, and very few in the Alps.”

  However, Wagnon also cautioned that in some specific cases, glacier flow and associated serac fall can be modified by climate change. For an example, he referred to a case under study in the Mont Blanc area in France, where a serac barrier at 3,700 m, on the Taconnaz glacier, is dominating the town of Chamonix.

  Such a glacier will be moving slowly because the its temperature keeps parts of it from melting. Since the amount of warming is sensitive to elevation, parts of glaciers at critical altitudes could warm up to close to 0° C and accelerate “from 1-10 m/year to 10-50 m/year”, precipitating a serac fall. On the Alps, the critical altitude above which the falls are likelier to happen is in the range of 3,500-3,900 m. On the Himalayas, around 6,000 m.

  “But really, take care, it is in very few cases,” Wagnon concluded.

  Not a glacial recession

  At the end of the Himalayas cryosphere conference, ICIMOD published a report titled ‘Glacier status in Nepal and decadal change from 1980 to 2010 based on Landsat data (2014)‘. One of its conclusions is that the total glacier area decreased by 24% between 1977 and 2010, and, on average, glaciers were also found to be receding at 38 km² per year.

  Thus, the corresponding ice reserves had dwindled by around 129 km³ in the same period. The report’s authors note that while the impact of climate change on avalanches and serac falls is not fully known, rising local temperatures affect different physical features to different extents. As a result, they write, smaller glaciers that sport a larger surface area, those at lower elevations and with less-sloping surfaces are more pliant to warmer climes.

  At the same time, the authors of the report advised caution in the clarification. Between 1980 and 1990, they speculate that the rate of ice loss could have been overestimated by the misclassification of snow as glacier ice – a characterization that’s yet to be fully understood.

  (Hat-tip to Siddharth Varadarajan)

  2014.05.24

• Ambivalent promises for S&T in the BJP manifesto

  The Copernican
  April 7, 2014

  Even though they haven’t been in power for the last decade, the Bharatiya Janata Party (BJP) concedes no concrete assurances for science & technology in the country in its manifesto ahead of the 2014 Lok Sabha polls. However, these subjects are geared to be utilised for the benefit of other sectors in which specific promises feature aplenty. Indeed, the party’s S&T section of the manifesto reads like a bulleted list of the most popular problems for scientific research in India and the world, although that the party has taken cognizance of this-and-that is heartening.

  The BJP makes no mention of increasing India’s spending on S&T while the Indian National Congress promises to do that to 2% of GDP, a long-standing demand. On the upside, however, both parties mention that they would like to promote private sector involvement in certain areas like agriculture, education, transportation and public infrastructure, but only the BJP mentions it in the context of scientific research.

  As things stand, private sector involvement in scientific research in India is very low. A DST report from May 2013 claims that it would like to achieve 50-50 investment from public and private participants by 2017, while the global norm stands at 66-34 in favour of private. It is well-documented that higher private sector involvement, together with more interdisciplinary research, reduces the time for commercialization of technologies – which the BJP aspires to in its manifesto. However, the party doesn’t mention the sort of fiscal and policy benefits it will be willing to use to stimulate the private sector.

  Apart from this, there are other vague aspirations, too. Sample the following.

  • Promotion of innovation by creating a comprehensive national system of innovation
  • Set [up] an institute of Big data and Analytics for studying the impact of big data across sectors for predictive science
  • Establish an Intellectual Property Rights Regime

  Climate change

  There is also mention of tackling climate change, with a bias toward the Himalayan region. Under the S&T section, there’s a point about establishing a “Central University dedicated to Himalayan technology”. With respect to conservation efforts, BJP proposes to “launch ‘National Mission on Himalayas’ as a unique programme of inter-governmental partnership, in coordinated policy making and capacity building across states and sectors”, not to mention promote tourism as well.

  The BJP also says it would like to make the point of tackling climate change a part of its foreign policy. However, its proposed power generation strategy does also include coal, natural gas and oil, apart from wanting to maximise the potential of renewable energy sources. Moreover, it also promotes the use of carbon credits, which is an iffy idea as this is a very malleable system susceptible to abuse, especially by richer agents operating across borders.

  “Take steps to increase the domestic coal exploration and production, to bridge the demand and supply gap. Oil and gas explorations would also be expedited in the country. This will also help to reduce the import bill.”

  Until here, not much is different from what the Congress is already promising, albeit with different names.

  The BJP appears to be very pro-nuclear. Under its ‘Cultural Heritage’ section, the manifesto mentions Ram Setu in the context of its vast thorium deposits. How this is part of our cultural heritage, I’m not sure. The party also proposes to build “world class, regional centres of excellence of scientific research” for nanotechnology, material sciences, “thorium technology” and brain research. Sure, India has thorium reserves, but the design for a thorium-based nuclear power plant came out only in February 2014, and an operational system is only likely to be ready by the end of this decade.

  Troubling stuff

  If spending doesn’t increase, these promises are meaningless. Moreover, there are also some pending Bills in the Lok Sabha concerning the setting up of new universities, as well as a materials science initiative named ISMER pending from 2011. With no concrete promises, will those initiatives set forth by the INC but not really followed through see the light of day?

  In fact, two things trouble me.

  1. A no-mention of scientific research that is not aimed at improving the quality of life in a direct way, i.e. our space program, supercomputing capabilities, fundamental research, etc.
  2. How the private sector is likely to be motivated to invest in government-propelled R&D, to what extent, and if it will be allowed to enter sensitive areas like power generation.

  Clearly, the manifesto is a crowd-pleaser, and to that end it has endeavoured to bend science to its will. In fact, there is nothing more troubling in the entire document than the BJP’s intention to “set up institutions and launch a vigorous program to standardize and validate the Ayurvedic medicine”. I get that they’re trying to preserve our historical traditions, etc., but this sounds like an agenda of the Minitrue to me.

  And before this line comes the punchline: “We will start integrated courses for Indian System of Medicine (ISM) and modern science and Ayurgenomics.”

  2014.04.08

• Temper worsening? Could be the climate.

  

  A study of studies by economists from Princeton and UCal, Berkeley, has found that as the climate worsens due to global warming, human violence is likely to get more frequent and intensified. The economists don’t know the precise terms of this intriguing relationship, but think a broad range of factors including neurophysiology and economic duress could be driving it. One significant finding is that one standard-deviation’s increase in some key climate variable’s value, like temperature, is likely to cause a whopping 14% rise in violence.

  The study is also important, claimed Edward Miguel, one of the authors from UCal, because it provides a lot of quantitative evidence to their claims that was missing earlier. It tracked the climate and human conflicts since 8,000 BC, and studied them in a regression framework that threw up the positive correlation conclusion. I corresponded with Prof. Miguel on this for my story in The Hindu. Also, here’s the abstract of their paper.

  2013.08.03