Thursday, December 31, 2015

2138. Climate Chaos, Across the Map

By Justin Gillis,The New York Times, December 30, 2015
Thirteen inches of rain fell on Hoinster Pass in Lake District, U.LK.  in 24 hours. 
What is going on with the weather?

With tornado outbreaks in the South, Christmas temperatures that sent trees into bloom in Central Park, drought in parts of Africa and historic floods drowning the old industrial cities of England, 2015 is closing with a string of weather anomalies all over the world.

The year, expected to be the hottest on record, may be over at midnight Thursday, but the trouble will not be. Rain in the central United States has been so heavy that major floods are beginning along the Mississippi River and are likely to intensify in coming weeks. California may lurch from drought to flood by late winter. Most serious, millions of people could be threatened by a developing food shortage in southern Africa.

Scientists say the most obvious suspect in the turmoil is the climate pattern called El Niño, in which the Pacific Ocean for the last few months has been dumping immense amounts of heat into the atmosphere. Because atmospheric waves can travel thousands of miles, the added heat and accompanying moisture have been playing havoc with the weather in many parts of the world.

But that natural pattern of variability is not the whole story. This El Niño, one of the strongest on record, comes atop a long-term heating of the planet caused by mankind’s emissions of greenhouse gases. A large body of scientific evidence says those emissions are making certain kinds of extremes, such as heavy rainstorms and intense heat waves, more frequent.

Coincidence or not, every kind of trouble that the experts have been warning about for years seems to be occurring at once.

“As scientists, it’s a little humbling that we’ve kind of been saying this for 20 years now, and it’s not until people notice daffodils coming out in December that they start to say, ‘Maybe they’re right,’ ” said Myles R. Allen, a climate scientist at Oxford University in Britain.

Dr. Allen’s group, in collaboration with American and Dutch researchers, recently completed a report calculating that extreme rainstorms in the British Isles in December had become about 40 percent more likely as a consequence of human emissions. That document — inspired by a storm in early December that dumped stupendous rains, including 13 inches on one town in 24 hours — was barely finished when the skies opened up again.

Emergency crews have since been scrambling to rescue people from flooded homes in Leeds, York and other cities. A dispute has erupted in Parliament about whether Britain is doing enough to prepare for a changing climate.

Dr. Allen does not believe that El Niño had much to do with the British flooding, based on historical evidence that the influence of the Pacific Ocean anomaly is fairly weak in that part of the world. In the Western Hemisphere, the strong El Niño is likely a bigger part of the explanation for the strange winter weather.

The northern tier of the United States is often warm during El Niño years, and indeed, weather forecasters months ago predicted such a pattern for this winter. But they did not go so far as to forecast that the temperature in Central Park on the day before Christmas would hit 72 degrees.

Matthew Rosencrans, head of forecast operations for the federal government’s Climate Prediction Center in College Park, Md., said that the El Niño was not the only natural factor at work. This winter, a climate pattern called the Arctic Oscillation is also keeping cold air bottled up in the high north, allowing heat and moisture to accumulate in the middle latitudes. That may be a factor in the recent heavy rains in states like Georgia and South Carolina, as well as in some of the other weather extremes, he said.

Although El Niños occur every three to seven years, most of them are of moderate intensity. They form when the westward trade winds in the Pacific weaken, or even reverse direction. That shift leads to a dramatic warming of the surface waters in the eastern Pacific.

“Clouds and storms follow the warm water, pumping heat and moisture high into the overlying atmosphere,” as NASA recently explained. “These changes alter jet stream paths and affect storm tracks all over the world.”

The current El Niño is only the third powerful El Niño to have occurred in the era of satellites and other sophisticated weather observations. It is a small data set from which to try to draw broad conclusions, and experts said they would likely be working for months or years to understand what role El Niño and other factors played in the weather extremes of 2015.

It is already clear, though, that the year will be the hottest ever recorded at the surface of the planet, surpassing 2014 by a considerable margin. That is a function both of the short-term heat from the El Niño and the long-term warming from human emissions. In both the Atlantic and Pacific, the unusually warm ocean surface is throwing extra moisture into the air, said Kevin Trenberth, a climate scientist at the National Center for Atmospheric Research in Boulder, Colo.

Storms over land can draw moisture from as far as 2,000 miles away, he said, so the warm ocean is likely influencing such events as the heavy rain in the Southeast, as well as the record number of strong hurricanes and typhoons that occurred this year in the Pacific basin, with devastating consequences for island nations like Vanuatu.

“The warmth means there is more fuel for these weather systems to feed upon,” Dr. Trenberth said. “This is the sort of thing we will see more as we go decades into the future.”

Tuesday, December 29, 2015

2137. Life Thrives in Isolated Poisonous Cave in Romania for 5.5 Million Years

By Jasmine Fox-Skelly, BBCSeptember 5, 2015
A waterscorpion (Nepa sp.) from Movile (Photo: Thierry Berrod, Mona Lisa Production/SPL)

In the south-east of Romania, in Constanța county close to the Black Sea and the Bulgarian border, there lies a barren featureless plain. The desolate field is completely unremarkable, except for one thing.

Below it lies a cave that has remained isolated for 5.5 million years. While our ape-like ancestors were coming down from the trees and evolving into modern humans, the inhabitants of this cave were cut off from the rest of the planet.

Despite a complete absence of light and a poisonous atmosphere, the cave is crawling with life. There are unique spiders, scorpions, woodlice and centipedes, many never before seen by humans, and all of them owe their lives to a strange floating mat of bacteria.

In 1986, workers in communist Romania were testing the ground to see if it was suitable for a power plant, when they stumbled across the Movile Cave. Romanian scientist Cristian Lascu was the first to make the dangerous descent.

Since then the cave has remained sealed by the Romanian authorities. Fewer than 100 people have been allowed inside Movile, a number comparable to those who have been to the Moon.

This is partly because the journey into the cave is extremely hazardous.

To enter, you must first lower yourself by rope 20m down a narrow shaft dug into the ground. The only light is from your helmet, which bounces around the walls as you descend.

You must then climb down through narrow limestone tunnels coated in an ochre clay, in pitch darkness and temperatures of 25 °C.  These paths eventually open out into a central cavern containing a lake.

In 2010, microbiologist Rich Boden, who was then at the University of Warwick in Coventry, UK, became roughly the 29th person to see the cave.

"It's pretty warm, and very humid so it feels warmer than it is, and of course with a boiler suit and helmet on that doesn't help," says Boden, who is now at the University of Plymouth in the UK.

"The pool of warm, sulphidic water stinks of rotting eggs or burnt rubber when you disturb it as hydrogen sulphide is given off.”

In the lake room, the atmosphere is heavy with harmful gases, principally carbon dioxide as well as the hydrogen sulphide from the water.

What's more, the air is low in oxygen: it contains just 10% oxygen rather than the usual 20%. Without breathing apparatus, you would soon develop a headache. Visitors can only stay down for 5 or 6 hours before their kidneys pack in.

To explore the rest of the cave, you must dive into the lake and navigate narrow underwater passageways, squeezing through tiny gaps in the rock before emerging into airspaces called air bells.

Doing this in complete darkness is the most dangerous part of exploring the cave. You are far from the surface, so getting stuck or losing your way in the maze of tunnels would be lethal. The experience is said to be terrifying – and that's even if you don't have a problem with creepy-crawlies.

Despite the dark and the dangerous gases, Movile Cave is crawling with life. So far 48 species have been identified, including 33 found nowhere else in the world.

There are all sorts of scuttling and slithering things. Snails and shrimps try to avoid the spiders and waterscorpions. In the air bells, leeches swim across the water and prey on earthworms.

Strangely, the worse the air gets the more animals there are. It's not at all obvious why that should be, or how the animals survive at all.

On the surface, plants use sunlight to extract carbon dioxide from the air and turn it into organic compounds. They can then use these chemicals to grow leaves, roots and bulbs. Animals then feed on these plant tissues.

Without sunlight, the animals in Movile Cave seem to be without a source of food.

In most caves, animals get their food from the water dripping down from the surface. This water can often be seen in the form of stalactites and stalagmites.

However, Movile Cave has a thick layer of clay above it, which is impermeable to water. When Lascu first visited, he could not find any stalactites or stalagmites, or any other sign of water coming from the surface.

The mystery deepened when scientists analysed the water in the cave for radioactive caesium and strontium. The 1986 nuclear accident at Chernobyl had released lots of these metals, which had found their way into the soils and lakes surrounding Movile Cave. However, a 1996 study found no traces of them inside the cave.

That means the water isn't coming from above, so it must be coming from below. It now seems that the water in Movile Cave comes from spongy sandstones where it has lain for 25,000 years.

However, this still doesn't explain how the animals in the cave survive. Tests have shown that the water flowing in does not contain any food particles.

Instead, the food comes from the strange frothy foam sitting on top of the water.
This floating film, which looks like wet tissue paper and can even be torn like paper, contains millions upon millions of bacteria known as “autotrophs".

"These bacteria get their carbon from carbon dioxide just like plants do," says Boden. "The carbon dioxide level in the cave is about 100 times higher than normal air. But unlike plants, they obviously can't use photosynthesis as there is no light.”

Rather than using light as an energy source, the Movile bacteria use a process known as chemosynthesis.

"They get the energy needed… from chemical reactions: the key ones being the oxidation of sulphide and similar sulphur ions into sulphuric acid, or the oxidation of ammonium found in the groundwaters to nitrate," says Boden.

These chemosynthetic bacteria help explain why the cave is so large and the air is so thick with carbon dioxide.

"Sulphuric acid actually erodes the limestone, which is gradually making the cave bigger," says Boden. "The process releases carbon dioxide, which is why levels are so high.”

Another major group of bacteria get their energy and carbon from the methane gas that bubbles up through the waters of the cave. They are called methanotrophs.

Boden describes methanotrophs as "messy eaters" that "constantly leak metabolic intermediates like methanol and formate" into the surrounding water. In turn, these chemicals are food for other species of bacteria.

This may all sound very peculiar, and in some ways it is. Movile is the only cave whose ecosystem is known to be supported in this way, and the only such ecosystem on land.

But according to microbiologist J. Colin Murrell of the University of East Anglia in Norwich, UK, the bacteria in Movile Cave are remarkably simple and not at all unusual.
"The bacteria get all of their carbon from just one source, be it methane or carbon dioxide," says Murrell. "That means that all of the components of their cells, be it the DNA in their nucleus, the lipids in their cell membrane and the proteins in their enzymes, are made from the same simple ingredient.”

The Movile bacteria are also very similar to bacteria found elsewhere, despite having being trapped in the cave for over 5 million years.

"Methanotrophs are everywhere: the Roman Baths at Bath, the surface of seawater, the mouths of cattle and probably the human mouth and gut," says Boden. "Autotrophic bacteria of the same types we found at Movile are found in almost all soils and on the surface of the skin.”

The same cannot be said for the animals of the cave. Millions of years of isolation has transformed them.

Many are born without eyes, which would be useless in the dark. Almost all are translucent as they have lost pigment in their skin. Many also have extra-long appendages such as antennae to help them feel their way around in the darkness.

There are no flies in Movile Cave, but the spiders still spin webs. Small insects called springtails bounce into the air and get caught in the webs.

In 1996, researchers categorised the animals in the cave. They included 3 species of spider, a centipede, 4 species of isopod (the group that includes woodlice), a leech never seen anywhere else in the world, and an unusual-looking insect called a waterscorpion.

Strangely, one of the spiders was closely related to a spider found in the Canary Islands – which lie over 4000km to the west, off the north-west coast of Africa.
That raises the question, how and why did the animals get into the cave?

One theory is that back at the end of the Miocene Epoch, about 5.5 million years ago, the climate of the northern hemisphere changed. As Africa moved north it stopped the Atlantic from flowing into the Mediterranean Sea, drying it out.

This could have forced the animals to seek refuge in the sulphurous underworld of Movile Cave. It would have been a haven, with thermal waters providing constant warmth, no competitors or predators, and a rich source of food.

The problem with this theory is that it is difficult to prove.

"It's very likely that the bacteria have been there a lot longer than five million years, but that the insects became trapped there around that time," says Murrell. "They could have simply fallen in and become trapped when the limestone cast dropped, sealing the cave until it was discovered again in 1986.”

It may be that different animals arrived at different times. A 2008 study of Movile's only snail suggested that it has been down there for just over 2 million years. When it entered the cave, the ice age was just beginning, and the snail may have escaped the cold by going underground.However they got there, it seems that Movile's inhabitants are now trapped for good. We could learn a lot from them.

The bacteria's ability to oxidise methane and carbon dioxide is of particular interest. These two greenhouse gases are the biggest culprits for global warming, so researchers are desperate to find efficient ways to remove them from the atmosphere.

The Movile Cave microbes could also offer hints about how the first life formed on Earth. They are genetically similar to those found in geothermal vents, which are also rich in carbon dioxide, sulphides and ammonia.

The conditions in both places may well be similar to the primordial Earth. In our world's early years, the Sun's light was obscured by an atmosphere thick with carbon dioxide, methane and ammonia. It could be that the first living cells were similar to those found in Movile Cave.

Almost 30 years after its discovery, Movile Cave remains perhaps the most isolated ecosystem on the planet. It surely has many more secrets to give up. There are plenty more organisms buried in the cave's sediments, waiting to be identified, and they could help us understand some of our deepest questions about the nature of life.

Saturday, December 26, 2015

2136. Earth Has Lost a Third of Arable Land in Past 40 Years, Scientists Say

By Oliver Milman, The Guardian, December 2, 2015

The world has lost a third of its arable land due to erosion or pollution in the past 40 years, with potentially disastrous consequences as global demand for food soars, scientists have warned.

New research has calculated that nearly 33% of the world’s adequate or high-quality food-producing land has been lost at a rate that far outstrips the pace of natural processes to replace diminished soil.

The University of Sheffield’s Grantham Centre for Sustainable Futures, which undertook the study by analysing various pieces of research published over the past decade, said the loss was “catastrophic” and the trend close to being irretrievable without major changes to agricultural practices.

The continual ploughing of fields, combined with heavy use of fertilizers, has degraded soils across the world, the research found, with erosion occurring at a pace of up to 100 times greater than the rate of soil formation. It takes around 500 years for just 2.5cm of topsoil to be created amid unimpeded ecological changes.

“You think of the dust bowl of the 1930s in North America and then you realise we are moving towards that situation if we don’t do something,” said Duncan Cameron, professor of plant and soil biology at the University of Sheffield.

“We are increasing the rate of loss and we are reducing soils to their bare mineral components,” he said. “We are creating soils that aren’t fit for anything except for holding a plant up. The soils are silting up river systems – if you look at the huge brown stain in the ocean where the Amazon deposits soil, you realise how much we are accelerating that process.

“We aren’t quite at the tipping point yet, but we need to do something about it. We are up against it if we are to reverse this decline.”

The erosion of soil has largely occurred due to the loss of structure by continual disturbance for crop planting and harvesting. If soil is repeatedly turned over, it is exposed to oxygen and its carbon is released into the atmosphere, causing it to fail to bind as effectively. This loss of integrity impacts soil’s ability to store water, which neutralizes its role as a buffer to floods and a fruitful base for plants.

Degraded soils are also vulnerable to being washed away by weather events fueled by global warming. Deforestation, which removes trees that help knit landscapes together, is also detrimental to soil health.

The steep decline in soil has occurred at a time when the world’s demand for food is rapidly increasing. It’s estimated the world will need to grow 50% more food by 2050 to feed an anticipated population of 9 billion people. According to the UN’s Food and Agriculture Organisation, the increase in food production will be most needed in developing countries.

The academics behind the University of Sheffield study propose a number of remedies to soil loss, including recycling nutrients from sewerage, using biotechnology to wean plants off their dependence upon fertilizers, and rotating crops with livestock areas to relieve pressure on arable land.

Around 30% of the world’s ice-free surfaces are used to keep chicken, cattle, pigs and other livestock, rather than to grow crops.

“We need a radical solution, which is to re-engineer our agricultural system,” Cameron said. “We need to take land out of production for a long time to allow soil carbon to rebuild and become stable. We already have lots of land – it’s being used for pasture by the meat and dairy industries. Rather than keep it separated, we need to bring it into rotation, so that that there is more land in the system and less is being used at any one time.”

Cameron said he accepted this would involve direct government intervention, funding for farmers and “brave” policymaking.

“We can’t blame the farmers in this. We need to provide the capitalisation to help them rather than say, ‘Here’s a new policy, go and do it,’” he said. “We have the technology. We just need the political will to give us a fighting chance of solving this problem.

2135. A Case of Bourgeois Socialism: A Moral Index for Capitalism?

By Alessandra Stanley, The New York Times, December 20, 2015
Activists outside Paul Tudor Jone II estate protesting the influence of hedge-fund managers. Photo: Andrew Sullivan for the New York Times. 
Paul Tudor Jones II, the hedge-fund billionaire, has a plan to reduce income inequality. He wants to rate companies on their probity, not their profits.

“The wealth gap, that’s the single most important issue in this country,” he said in September while unveiling Just Capital, a nonprofit organization that he created with Deepak Chopra, the spiritual self-help author and wellness entrepreneur who taught Mr. Jones how to meditate.

Just Capital will rank corporations on how well, or “justly,” they treat employees, society and the environment. The idea is to laud companies that offer better pay, happier workplaces and greater transparency — and perhaps shame others to follow suit.

This kind of moral index, Mr. Jones said, “could not only impact investors, it could impact consumers, it might impact the way companies hire, the way people go and work with companies; it will impact boardrooms, everything.”

The project began, improbably enough, in 2011 in the chic Manhattan design store ABC Carpet and Home when Mr. Chopra was whisked away from his salon in a friend’s chauffeured car to an Occupy Wall Street rally.

Today, with a presidential election looming and calls for the wealthy to pay more in taxes coming not only from populist politicians but also from billionaires like Warren E. Buffett, even members of the top 1 percent of the 1 percent are passionately inveighing against the wealth gap.

“The middle-class guy who’s making the $50,000 a year realizes, ‘I’m being taken advantage of,’ ” warned Carl Icahn, a corporate raider turned activist investor, in a video titled “Danger Ahead that he released in late September.

While there has not exactly been a groundswell among the wealthy to significantly raise their own taxes, Mr. Icahn and Mr. Buffett are among several of America’s prominent top earners who have endorsed changing the tax loophole that treats a large portion of private-equity and hedge-fund managers’ income — known as carried interest — as more lightly taxed capital gains and require it to be taxed as regular salary. In a statement responding to questions for this article, Mr. Jones said his “strong opinion” was that carried interest should be taxed as ordinary income.

“Billionaires see a backlash coming,” said Sam Wilkin, an economist and author of “Wealth Secrets of the One Percent.” Mr. Jones has experienced it firsthand. In March, the Hedge Clippers, a coalition of labor groups and community activists, marched on his Greenwich, Conn., estate to protest the influence of hedge-fund managers.

At the same time, some of America’s wealthiest are responding with an unprecedented flood of money into politics, largely supporting Republican candidates who have pledged to cut taxes. A New York Times investigation documented in October how 158 families were responsible for almost half the money raised in the current presidential race. People from the finance industry lead the list.

This year Mr. Jones said in a TED talk that traditionally there are three ways to change income inequality: “By revolution, higher taxes or wars.” His alternative is Just Capital.

Mr. Jones argues that income inequality is being driven by what he calls “shareholder hegemony,” the principle that companies first and foremost should satisfy investors. The solution is for companies to make social responsibility as important as profits and share price.

Mr. Jones, who declined to be interviewed, has a net worth Forbes estimates at $4.7 billion and was one of the few hedge-fund managers who foresaw the 1987 market crash. He is known for founding the Robin Hood Foundation, a charitable organization started in 1988 that raised $101 million last year for anti-poverty programs in New York.

Just Capital’s mission fits into an existing trend. Socially responsible investing, the favoring of companies that demonstrate environmental and social awareness, is a growing movement, driven in large part by the economic ascendance of millennials and women. As of this month, Morningstar said about 2 percent of the mutual funds it tracked were tagged “socially conscious.” Such funds “typically perform on par or a little better than conventional funds,” said Jon Hale, director of manager research at Morningstar.

Not all economists agree with Mr. Jones’s notion that monitoring corporate behavior would narrow the distance between the very rich and the rest. Mr. Wilkin, the economist, argued that inequity was driven not just by bloated executive compensation or the single-minded pursuit of profit, but also by what he called a two-tier economy in which some industries, like technology, finance and health care, soared ahead and left the rest behind. Just Capital, he said, was “wishful thinking that there is a market solution to income inequality that doesn’t involve increasing taxes.”

There are many nonprofits that seek to address income inequality. Mr. Jones and Mr. Chopra bring a waft of New Age spirituality to theirs. The Just Capital board includes Arianna Huffington, a founder of The Huffington Post, and several wealthy business leaders who also are directors of the Chopra Foundation.

Mr. Chopra, in an interview, described his friend as being on a path of self-discovery. “This is an evolution for him.”

It all started with meditation. In early October 2011, Dylan Ratigan, an MSNBC anchor who later left to become what he described as a “sustainability entrepreneur,” was on his way to a private meditation session at Mr. Chopra’s salon in ABC Carpet and Home just as the Occupy Wall Street protests were getting started in Zuccotti Park. On an impulse, Mr. Ratigan told his teacher that he had a car waiting downstairs and asked Mr. Chopra to go with him to the park.

When they arrived, Mr. Ratigan asked the protesters to let Mr. Chopra speak. Some of them fiercely objected to letting a celebrity jump the line, but Mr. Ratigan prevailed, and Mr. Chopra led the crowd in a meditative prayer that, as he put it, “quieted the angry rhetoric.” That fall, he became a featured guest at several Occupy events and was so struck by the “perceived injustice” fueling the protests that he told a friend: “We need to do something about this.”

The idea for Just Capital emerged from a seminar Mr. Chopra held at Columbia Business School called “Just Capital and Cause-Driven Marketing.” A student suggested creating an index of companies based on their value to society, not quarterly profits. Mr. Chopra took the idea to Mr. Jones, whom he had met through Mr. Jones’s wife, Sonia, a yoga and wellness enthusiast.

Mr. Chopra, who wears crystal-studded eyeglass frames, blends spiritual and commercial success with celebrity hobnobbing — he does workshops with Oprah Winfrey and made a recording of love poetry with Madonna. “He’s very good at the diplomacy of wealth and power,” Mr. Ratigan said.

Mr. Chopra said that, so far, he had not received skeptical responses to the Just Capital idea, but he conceded that the jury had been small and “self-selected.”

Mr. Jones set up the foundation in 2013, hired a staff and underwrote a survey of 43,000 Americans to determine what people most valued in a company. The No. 1 factor was pay and benefits. (At No. 10 was creating jobs in the United States.) Next year Just Capital plans to publish a ranking of the top 1,000 publicly traded companies based on a scale derived from the survey. “Americans want a seat at the table,” Mr. Jones said at the September presentation.

There are many research firms, including MSCI and Sustainalytics, that examine companies for social responsibility, although their data is mostly reserved for clients and subscribers. Just Capital plans to make its ratings public at no charge.

Because Just Capital will examine only publicly traded corporations, Mr. Jones’s hedge fund and thousands of others like it will be exempt from scrutiny. At the Just Capital presentation, Mr. Jones said he checked to make sure his own company, Tudor Investment Corporation, was in line with Just Capital’s principles.

Tudor Investment employs about 400 people, according to a spokesman, Patrick Clifford. Its traders, of course, make well above a living wage.

At first, the wages of gardeners, dishwashers and janitors at Tudor were not included in the review because they are employed by subcontractors, not Tudor directly. When managers examined the salaries, however, they found that the firm had 16 subcontracted workers who were paid $10.50 an hour.

“It was literally eye-opening and embarrassing at the same time,” Mr. Jones said. He said he raised their hourly rate to $15.

For comparison, in Fairfield County, where Tudor is based, janitors who belong to Local 32BJ of the Service Employees International Union make $14.10 an hour, not including benefits, and $20.49 an hour with benefits factored in. According to the M.I.T. living wage calculator, the living wage for a single worker in the county is $12.78 an hour and for an adult with one child it is $27.72.

Last spring, Mr. Jones leased an office and bought a $71 million house in Palm Beach, Fla., in a state with no income tax. He also said he increased the percentage of profit the company donates to charity to 4 percent a year from 1 percent. According to CECP, an organization that monitors corporate giving trends, the industry median last year was 1 percent.

At the conference this year announcing Just Capital, a guest asked him if he was the best messenger to preach corporate altruism, given that “shareholder hegemony” helped make him wealthy. Mr. Jones had a ready reply. He had been rethinking the capitalist dream, he said, ever since hearing about the “giving pledge,” a promise made by Bill Gates, Mr. Buffett and others to give away much of their wealth.

“What’s the purpose of accumulating all this money when I’m just going to give it back to the people I conceivably took it from?” Mr. Jones said.

Friday, December 25, 2015

2134. A Brief History of How 2 Degrees Celsius Global Warming Became the Upper Limit for Climate Policy

By Carbon Brief, December 8, 2014

Limiting warming to no more than two degrees has become the de facto target for global climate policy. But there are serious questions about whether policymakers can keep temperature rise below the limit, and what happens if they don’t.
As climate negotiators meet in Lima to discuss a new global climate deal that could limit warming to two degrees or less, we look at each of the issues in turn.
Here, we take a look at where the two degree target came from, and how it has ended up guiding international climate policy.
Infographic. Two degrees: A selected history of climate change's speed limit.
Two degrees: A selected history of climate change’s speed limit. Credit: Rosamund Pearce for Carbon Brief.
A selected history of the two degrees limit. Credit: Rosamund Pearce.
Woven into the fabric of climate policy
Perhaps surprisingly, the idea that temperature could be used to guide society’s response to climate change was first proposed by an economist.
In the 1970s, Yale professor William Nordhaus alluded to the danger of passing a threshold of two degrees in a pair of now famous papers, suggesting that warming of more than two degrees would push the climate beyond the limits humans were familiar with:
“According to most sources the range of variation between between distinct climatic regimes is on the order of around 5°C, and at present time the global climate is at the high end of this range. If there were global temperatures more than 2°C of 3°C above the current average temperature, this would take the climate outside of the range of observations which have been made over the last several hundred thousand years.”
Screen Shot 2015-04-07 At 14.35.34
Global mean temperature change projection from Nordhaus’ 1977 paper.
It was a tangential point in the papers. But this, say Carlo and Julia Jaeger from the Potsdam Institute for Climate Impact Research, who have researched the history of the target, is “perhaps the first suggestion to use two degrees as a critical limit for climate policy.”
More than a decade later, in 1988, NASA professor Jim Hansen gave the issue of climate change a boost, linking greenhouse gas emissions to global warming in a testimony to the US Congress.
Hansen 1988
James Hansen presenting early evidence of global warming to the US Congress in 1988. Credit: NASA
Hansen was one of the first scientists to publicly state that rising emissions could have a dangerous impact. His evidence concluded that the earth was warmer in 1988 than ever before, that human-caused emissions were responsible for the warming, and that temperatures were likely to continue to rise, increasing the likelihood of extreme weather events.
Screen Shot 2014-11-21 At 12.23.46 (2)
Temperature projection graph  submitted to Congress by James Hansen as part of evidence of human caused global warming in 1988.
But Hansen didn’t offer Congress a definition of what constituted dangerous climate change. So in 1990 a team of researchers from the Stockholm Environment Institute (SEI) took it upon themselves to try and answer that question.
In a report looking at the potential impacts of of rising greenhouse gas emissions, they discussed a number of ways scientists could measure the world’s efforts to limit climate change. They suggested curbing sea level rise or restricting the concentration of carbon dioxide in the atmosphere as two options. Another was to use global warming as a guide for where to set an overarching limit.
Based on scientific understanding at the time, SEI suggested that to avoid the worst impacts of climate change, a limit should be set at two degrees. But, the report warned, the higher the temperature rise, the bigger the risks from climate change.
“Temperature increases beyond 1.0°C may elicit rapid, unpredictable, and non-linear responses that could lead to extensive ecosystem damage,” the report said, suggesting there is nothing necessarily ‘safe’ about a two degree limit.
SEI 2 Degrees Reference Highlighted
An early reference to the two degrees limit in the Stockholm Institute’s  Targets and Indicators of Climate Change report.
Two degrees and international climate politics
Soon after the institute’s intervention, the idea of a two degrees limit started to appear in more mainstream political settings.
In 1992, world leaders signed the United Nations Framework Convention on Climate Change at the Earth Summit in Rio de Janeiro. Article 2 of the convention commits countries to stabilising “greenhouse gas concentrations in the atmosphere at a level that would prevent dangerous anthropogenic interference with the climate system”.
It stopped short of defining the level at which climate change became “dangerous”, however, despite growing calls for two degrees of warming to be set as a limit.
UN Earth Summit
World leaders at the 1992 Earth Conference in Rio de Janeiro. Credit:  United Nations
Then, in 1996, the European Council of environment ministers became the first political body to lend formal support. It declared that “global average temperatures should not exceed 2 degrees above pre-industrial level”.
Signatories to that statement included figures who now sit at the forefront of international climate politics – the UK’s John Gummer, now chair of the UK’s Committee on Climate Change, and Germany’s Angela Merkel, who is currently spearheading Germany’s transition to renewables.
Merkel COP1
Germany’s current chancellor, Angela Merkel, representing the country as environment minister at the first UNFCCC meeting in Berlin in 1995. Credit: International Institute for Sustainable Development
A year later, 193 countries signed the world’s first binding agreement to cut emissions: the Kyoto Protocol. The treaty set limits on countries’ emissions, taking into account their historical contribution to climate change and ability to implement policies, with the aim of cutting global emissions five per cent on 1990 levels by 2012.
Negotiators spent the next decade trying to persuade countries to ratify the treaty,
figuring out how the protocol would work, and eventually trying to agree a replacement for the protocol as its 2012 expiration date loomed into view.
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Article 3 of the Kyoto Protocol.
The Kyoto Protocol itself does not mention the two degrees goal. But media coverage at the time linked the treaty to two degrees. The New York Times, for example, pointed to the Intergovernmental Panel on Climate Change’s (IPCC) conclusion that two degrees of warming would be dangerous, and described the protocol as the “beginning, not an ending” of the world’s efforts to prevent climate change.
In 2005, with the treaty ratified by almost 160 countries, the protocol formally came into force. It was hamstrung, however, by the absence of the world’s largest historical emitter: the US. The country remained open to the idea of a global climate deal, but didn’t want it to extend as far as the Kyoto protocol’s goals.
The two degrees limit was a particular point of contention for US diplomats, showing how symbolically important it had become. At the G8 summit in 2008, they reportedly culled references to two degrees from a draft summit conclusion proposed by chancellor Merkel.
This set the tone for the next five years of international climate negotiations. In 2009, attention turned to trying to agree a new deal to replace the Kyoto protocol. Negotiators hoped the deal would put binding obligations to cut emissions on all the world’s major emitters, including the US and China.
joint-editorial published by 56 newspapers on the eve of 2009’s Copenhagen conference piled on the pressure, declaring:
“Climate change has been caused over centuries, has consequences that will endure for all time and our prospects of taming it will be determined in the next 14 days.”
Newspapers Copenhagen Climate Editorial
Three newspapers running the  joint-editorial calling for action at the Copenhagen climate summit.
The newspapers described what they saw as the reason for such urgency:
“The science is complex but the facts are clear. The world needs to take steps to limit temperature rises to 2°C, an aim that will require global emissions to peak and begin falling within the next 5-10 years. A bigger rise of 3-4°C – the smallest increase we can prudently expect to follow inaction – would parch continents, turning farmland into desert. Half of all species could become extinct, untold millions of people would be displaced, whole nations drowned by the sea.”
But despite media scrutiny and public backing for a deal being at an all time high, the conference ended in failure. Instead of a new, binding, global deal, world leaders agreed the Copenhagen Accord, which “recognised” the case for curbing emissions to prevent temperatures rising, but did not contain commitments to achieve the goal.
Copenhagen Conference World Leaders
World leaders at the Copenhagen climate conference in 2009. Credit:  White House
It took another year for the two degrees limit to be formally enshrined into international climate policy. The moment came in 2010, when countries signed the Cancun Agreements committing governments to “hold the increase in global average temperature below 2°C above pre-industrial levels.”
Countries have made only incremental progress towards this goal in recent years. But negotiators hope that 2015 will bring a new global climate deal, this time at a meeting in Paris.
The UK’s leader of the opposition and former energy and climate change secretary, Ed Miliband, who led the UK delegation in 2009, says that while the Copenhagen conference failed, Paris’s goal should be the same:
“… the answer is not to lower your ambition the next time round. It’s actually to say, ‘Well, we’ve still got the same ambition and we’re going to keep pushing and keep pushing until we actually succeed.'”
So, once again, world leaders will convene to try and find a way to prevent temperatures rising by more than two degrees, with the clock ticking.
A simple speed limit
Having been the totem of international climate negotiations for the past 40 years, it seems unlikely that the two degrees target will simply fade away post-2015. But the limit may find itself under pressure in a world that has to start adapting to warming, rather than just seeking to avoid it.
One of two degrees’ enduring strengths is its simplicity. The Intergovernmental Panel on Climate Change’s co-chair, Thomas Stocker, previously told Carbon Brief:
“The power of the 2°C target is that it is pragmatic, simple and straightforward to understand and communicate, all important elements when science is brought to policymakers.”
Richard Betts, a Met Office scientist, compares two degrees to a speed limit. He explains in a short blog post:
“The level of danger at any particular speed depends on many factors… It would be too complicated and unworkable to set individual speed limits for individual circumstances taking into account all these factors, so clear and simple general speed limits are set using judgement and experience to try to get an overall balance between advantages and disadvantages of higher speeds for the community of road users as a whole.”
Scientists expect the impacts of climate change to become increasingly stark over the coming century, however. That may destabilise the idea that there is a “safe” level of climate change that we can stay below.
And the longer the world delays cutting emissions, the more challenging meeting the two degrees goal will become.
But even if stopping surface temperatures rising ceases to be climate politics’ only goal, analysts are likely to continue to measure politicians’ responses in similar terms – regardless of whether the world prevents warming of two degrees.
Tomorrow we’ll look at the prospects of the world staying below the two degree limit. And on Wednesday we’ll explore what could happen if we don’t.