With climate change, uncertainty is no-one’s friend

Uncertainty cuts both ways highlights University of Bristol’s Stephan Lewandowsky – if your preferred estimate is at the low end of a range, you’re neglecting similarly likely high end estimates. Image credit: University of Bristol

Waiting longer to act on climate change will cost us more than taking immediate action. It’s a message that’s getting louder and louder, repeated from many sides. In March it was stressed by US Secretary of State John Kerry. In April it was highlighted by the UN Intergovernmental Panel on Climate Change (IPCC)’s latest report. Last month it was underlined by Hank Paulson, treasury secretary under George Bush, hedge fund manager Tom Steyer, and former New York Mayor Michael Bloomberg. This week the Council of Economic Advisors, the agency advising President Obama on economic policy, joined in.

These messages could hardly be any clearer, but still some of us remain uncertain on the need to act. The best argument for waiting until we’re more certain to act is that if climate change turns out to be harmless, our efforts to fight it will be wasted. Even simple things like current weather are enough to sway our opinions, and when uncertain it’s always tempting to feel like we don’t need to do anything. But that’s the wrong reaction to uncertainty on climate change, according to psychologist Stephan Lewandowsky from the University of Bristol, UK.

The researchers have found that greater uncertainty over how much Earth warms in response to our CO2 emissions would actually raise forecasts of average damage costs from climate change. Greater uncertainty also means projections see it as more likely that steps to cut emissions won’t keep the world below warming levels governments have agreed we must avoid. So, if we are unsure whether we can slow the climate juggernaut down before we smash into the wall, we’re better off hitting the brakes earlier. As Stephan explained, ‘uncertainty is no one’s friend’.

Evidence is piling up against the economic argument for waiting to see if climate sensitivity is less than 1°C per doubling of CO2. Image copyright Springer, see reference below.

Who can afford to hold back rising seas?

UK Prime Minister David Cameron visiting Dawlish a week after the storms that demolished the sea wall that supported the train line. Image copyright Number 10, used via Flickr Creative Commons license.

Taking the train along the Devon, UK, coast earlier this week I was hypnotised by the lapping waves I saw through the window, and their concealed power. On such a sunny day, the rail journey through Dawlish is perhaps the most beautiful I’ve been on. But in February its ocean-hugging route became its downfall, when storms demolished the sea wall it rests on. Now, thanks to 300 fluorescent-jacket clad workers who performed £35 million worth of repairs, the dangling tracks I saw on TV news are a fading memory. It’s an impressive achievement, but could we afford it if – due to climate change, for example – such ‘orange armies’ had to do battle more often?

The significance of that question was emphasised by Chris Field from Stanford University in California, when I saw him talk recently. Highlighting that all parts of the world are vulnerable to climate change, Chris showed the below image of New York City in 2011, during Hurricane Sandy. “The existing climate created a situation that caused over $50 billion in economic damage for a region of the world that had a vast amount of economic resources and had a response plan in place,” he underlined. “It just wasn’t a plan that was up to the challenges that they faced.” If climate change causes more $50 billion-damage events, can we afford that?

If New York can be taken unaware by Hurricane Sandy, what happens elsewhere, when sea level’s higher? Image credit: Chris Field/IPCC

Just before the ocean crippled the south-west UK’s rail services, Jochen Hinkel from the Global Climate Forum in Berlin, Germany, and his team were answering a similar question. In a paper published in the Proceedings of the National Academy of Sciences of the USA in February, Jochen looked at coastal flood damages from projected sea level rise. When I therefore asked him about his work, he was quick to put climate change-driven sea level rise’s role in Hurricane Sandy and this year’s UK storms into context.

Shrinking dairy’s carbon hoofprint

After 10,500 years of farming them, does climate change mean we humans must limit our reliance on cows, or just change how we treat them? Image copyright fishhawk, used via Flickr Creative Commons licence.

Whenever I come across cows here in the southwest of the UK, usually placidly munching on a mouthful of grass, they always seem too lovable to be villains. But as we face growing twin challenges of feeding the world and fighting climate change, they’re increasingly getting a bad reputation.

Some scientists highlight reducing how much beef we eat, in particular, as an important step towards future sustainability. They say only about three or four parts in 100 of the energy in livestock feed becomes our food, while the rest is lost as manure, heat, digestive gases and slaughter by-products. Switching to more intensively farmed chicken or pork and plant-based food would be more efficient, the argument goes. It also gives a greater chance to trap carbon from waste material, which might otherwise become planet-warming greenhouse gases, as biochar that can help improve soil fertility.

A couple of years back I put this to Peter and Henri Greig who run my favourite local butchers, Pipers Farm. As they showed us round their farm Peter explained how their Red Ruby cattle can graze Devon moorland that can’t be used for crops, before moving on to pasture. While I still don’t eat a lot of beef for both environmental and health reasons, that seems a good reason for not demonising cows entirely. In fact, a paper in the June 2014 issue of the Journal of Dairy Science highlights previous research that found more grazing land exists, unusable for human food, than cropping land.

We can’t ignore what that promises for feeding the world in the future, but we can’t ignore cows’ greenhouse gas emissions either. However, rather than beef cattle, the new paper’s authors focussed on reducing levels of the potent greenhouse gas methane coming out of the digestive systems of dairy cattle. Joanne Knapp, a consultant who has researched nutrition in ruminant animals like cattle, told me her team’s interest comes in part thanks to its backers: Innovation Center for US Dairy.

IPCC: Millions of words on climate change are not enough

The latest IPCC report has highlighted that it’s dead certain that the world has warmed, and that it’s extremely likely that humans are the main cause. Credit: IPCC

The most recent UN Intergovernmental Panel on Climate Change (IPCC) report saw perhaps the most severe conflict between scientists and politicians in the organisation’s existence. As its name suggests, governments take an active part in the IPCC process, whose latest main findings appeared between September 2013 and May 2014. Debate over what information makes the high-profile ‘Summaries for Policymakers’ is usually intense, but this time three graphs were dropped on politicians’ insistence. I show these graphs later in this blog entry.

At the Transformational Climate Science conference in my home town, Exeter, UK, earlier this month, senior IPCC author Ottmar Edenhofer discussed the ‘battle’ with governments on his part of the report. Another scientist who worked on the report highlighted confidentially to me how unusual the omission was.

To me, it’s more surprising that this hasn’t happened more often, especially when you look more closely at the latest report’s findings. There’s concrete certainty that warming is happening, and it’s extremely likely that humans are the dominant cause, it says. Governments have even – in some cases, begrudgingly – already signed up to temperature and CO2 emission targets reflecting this fact.

The inadequacy of those words is becoming ever more starkly obvious. Ottmar stressed that the emissions levels agreed at the United Nations’ Climate Change Conference in Cancún, Mexico, in November 2010, would likely need later emissions cuts the likes of which we’ve never seen before to avoid dangerous climate change. The latest IPCC report shines a floodlight on that inertia, which understandably cranks up the tension between researchers and politicians.

Ottmar was one of two co-chairs who led the ‘working group three’ (WGIII) section of the IPCC report that looks at how to cut greenhouse gas emissions. He stressed that the need to make these cuts comes from a fundamental difference between the risks that come from climate change and the risks of mitigation. We can heal economic damage arising from cutting emissions – reversing sea level rise isn’t so easy.

Results show quick CO2 ‘fix’ feasibility – but its future rests in government hands

The CarbFix project is trapping natural CO2 emissions underground as Iceland seeks to offset emissions from other sources. Image credit: Reykjavik Energy

Although CO2 can stay in the atmosphere, trapping heat, for thousands of years scientists think they have turned it into rock in just a few months. Juerg Matter from the University of Southampton, UK, and his colleagues in the CarbFix project have injected 170 tons of pure CO2 into the reactive basalt underneath Iceland. Their findings suggest around 85% of it reacted with the rock over the short distance between injection and monitoring boreholes in less than one year.

“We think that was because all that CO2 precipitated out as carbonate minerals in the reservoir,” Juerg, who’s also an adjunct scientist at Lamont-Doherty Earth Observatory in New York, told me. “To really prove it this summer we will drill a borehole into the injection reservoir to retrieve rock core samples.” But the CarbFix team has also emphasised this week that it will take higher carbon prices for this and other carbon capture and storage technology to fulfil their potential.

The latest UN Intergovernmental Panel on Climate Change (IPCC) says the cheapest way to avoid dangerous climate change is to stop using fossil fuels and switch to renewable energy. However time’s running out on that option, and the IPCC report therefore highlights the probable need to suck CO2 from the air. But before we capture CO2 straight out of the air, or even from the chimneys of power stations, we need somewhere to put it. Currently captured CO2 is simply pumped and stored underground as a gas, meaning care is needed to choose reservoirs that won’t leak. “Storage options right now are mainly in depleted gas and oil fields, in sedimentary rocks,” Juerg said.

In the air, CO2 eventually reacts with basalt naturally, but that process is far too slow to balance out what humans are emitting. Since 2007 the CarbFix team has been working to see if they can speed that process up by forcing CO2 underground. Not only would this quickly turn the gas into minerals and prevent leak worries, it would also greatly expand the number of places it could be stored. “The storage potential is just huge, there’s billions of tons of reservoir, because basically all the ocean floor is basalt,” Juerg highlighted.

Fairness instinct trumps economic expectations on climate costs

ETH Zurich’s Robert Gampfer hopes governments can learn from the climate negotiation games he ran. Image credit: ETH Zurich

We care about fairness in sharing climate change costs, although differences in who’s more vulnerable to it can affect our ideas of what exactly is fair. That’s the clear suggestion emerging from a set of climate change negotiation games run by Robert Gampfer from the Swiss Federal Institute of Technology, ETH Zurich. In his experiments, students from Zurich universities took on the role of countries in climate talks trying to agree how costs should be shared. Robert feels this unusual approach provides unique insights into our true attitudes, and could help guide our leaders in responding to them.

“Proposals that are perceived as very unfair are likely to meet public resistance, and governments will therefore be unlikely to agree to them in the international negotiations,” he told me. “But the experiment also showed that participants who were richer or more responsible for climate change often acted rather fairly, even if this meant higher costs for them. This is quite a far-reaching conclusion, but maybe governments of developed countries could actually sell costly climate agreements to their citizens if they perceive some fairness obligation to accept them.”

This study builds on a realisation Robert made when looking into possible topics for his climate politics PhD, which he’s now writing the final thesis for. “A lot of surveys on climate change and climate policies ask only very broad questions – whether you would support your country reducing its emissions or not, for example,” he observed. “But we know very little about how specific aspects of global climate politics influence people’s opinion, for example the debate on burden-sharing fairness. In a standard survey it is easy to be in favour of emission reductions, because stating this does not cost you anything. Real emission reductions probably would have some cost, for example through higher energy prices.”

In seeking deeper insights, Robert realised that political science and economic experiments hadn’t addressed fairness much either. “This might be because many think people’s fairness preferences are not important for an international climate agreement,” he said. “I find this quite surprising: in the negotiations, governments use fairness arguments very often. And they probably do this, among other reasons, because they will receive domestic support from their citizens for adopting such negotiating positions.”

The climate challenges that my morning toast poses

Britain’s wheatfields could become even more productive as the world warms – but that will have implications for further greenhouse gas emissions and fairness to countries less well positioned. Image credit: Tim Gage used via Flickr Creative Commons license

It may seem that nothing could be simpler than toast, but next time I see a slice pop up I’ll also see an emblem of the world’s future. That’s thanks to a UK study exploring the problems surrounding growing enough wheat for flour and other foods as the world warms and has ever more people in it. The issue is especially tangled, Mirjam Röder and her University of Manchester teammates show, as adapting farming for the future will likely increase greenhouse gas emissions, driving further warming. “Climate change and food security are two issues which can’t be decoupled,” Mirjam told me. “The same applies for mitigation and adaptation.”

Mirjam is part of the “Climate change mitigation and adaptation in the UK food system” project, led by Alice Bows-Larkin and backed by Manchester’s Sustainable Consumption Institute. One concern the project reflects is that without adaptation farming will probably be the industry worst hit by climate change, with worldwide productivity falling as temperatures rise. Meanwhile, farming also releases about one-tenth of the greenhouse gases we humans emit overall. “These are largely emissions other than CO2, such as nitrous oxide and methane, mainly occurring from natural processes,” Mirjam said. “They are much harder to reduce and control. Then of course global society is challenged by increasing global food demand. So we face a triad of challenges in the food system: we need to reduce emissions, while food demand is increasing and the sector is impacted by climate change.”

Alice and Mirjam’s team looked at wheat because it makes up almost a third of all cereals grown in the world. “Global wheat demand is projected to increase by about 30% by 2050,” Mirjam. “If we don’t find methods to reduce them, total emissions from producing more wheat will rise.” As well as gases released directly by bacteria and other soil microorganisms, emissions from wheat farming arise from the energy needed to produce nitrogen fertiliser. Whether growing more wheat or dealing with rising temperatures, farmers will need more fertiliser, driving more emissions and therefore further warming.

Renewable energy beats ‘clean coal’ on cost in Australia

A part of the extension of the Snowtown Wind Farm in South Australia that added 90 new 3 megawatt turbines. In South Australia wind farms contribute 27% of annual electricity, notes University of New South Wales’ Mark Diesendorf. Photo by David Clarke, used via Flickr Creative Commons license.

It’s unlikely that fossil fuel power stations that capture and store their CO2 emissions could supply eastern Australia’s electricity more cheaply than renewable energy technologies like solar and wind power. That’s according to a study based on hour-by-hour analysis of electricity demand by Ben Elliston, Iain MacGill and Mark Diesendorf from the University of New South Wales in Sydney. Although renewables are often seen as expensive, these findings highlight that they can be competitive after accounting for the impact of burning coal and gas on our climate. “Our studies, and those conducted by other research groups around the world, find that it is possible to operate reliable national and subnational electricity systems on predominantly renewable energy generated by commercially available technologies and that these systems are affordable,” Mark told me.

Ben is a PhD student, supervised by Iain and Mark, and together the three have sought to answer key questions about renewable energy. Is it possible to supply a whole electricity grid’s needs with these technologies, or are some ‘base-load’ coal or gas power stations needed to fall back on? And if it is possible, would it be affordable?

To answer these questions, Ben designed a computer programme to simulate running an electricity supply system. His program can go through a year’s hourly data on electricity demands, wind and sunshine over the region in a fraction of a second. “Everything else follows from this, provided of course one asks the right questions,” Mark noted.

Over the last two years they have published work exploiting that programme, first showing that it’s possible to reliably supply 100% of eastern Australia’s electricity using renewable energy. Wind and solar power supplied most of the electricity, but output from these technologies varies due to changes in weather. But rather than filling gaps with fossil fuels, they showed existing hydroelectric power stations and gas turbines burning biofuels could be used to meet the grid’s reliability standard.

Heat drives Pakistani migration

Shahdadpur, Sanghar district, Pakistan: Residents collecting their belongings on a higher ground outside village during floods. Though they may be displaced temporarily, Valerie Mueller from the International Food Policy Research Institute (IFPRI) in Washington DC and her team find high temperatures are more likely to drive permanent migration. Image credit: Oxfam International

Excessive rainfall rarely drives Pakistanis to permanently leave their villages, even when it causes hardship like the flooding that hit around a fifth of the country in 2010. Yet they do consistently move in response to extreme temperatures, Valerie Mueller from the International Food Policy Research Institute (IFPRI) in Washington DC and her colleagues have found. She says the finding is a first stage in establishing if, how, and why people’s choices are affected by climate and climate change. “This is a useful step in order to be able to predict migration flows and inform local governments how might they better prepare in terms of the delivery of resources and investing in infrastructure given the occurrence of extreme weather events,” she told me.

There are few efforts collecting information about who has migrated and why over long periods of time, especially in areas where extreme weather occurs. But IFPRI has a long history of evaluating questions linked to food security in countries across the world, including Pakistan. From 1986-1991 its Pakistan Rural Household Survey questioned 800 households about how they lived and farmed, and it has tracked those households ever since. “Local collaborators found the original households in 2001 and 2012 and asked the head of household or an otherwise knowledgeable person what happened to each household member who resided with them in 1991,” Valerie said. “Our study is one of the first to quantify long-term migration patterns over a long period of time.”

The follow-ups recorded the long-term movements and fortunes of 4,428 people from 583 households. The researchers combined these answers with temperature and rainfall data in one ‘logit’ and one ‘multinomial logit’ model designed to let them measure the odds that people moved. “The first model allows us to answer: What are the odds of a person moving out of the household in response to extreme temperature or rainfall?” Valerie explained. “The second model allows us to distinguish moves by location and allows us to answer the following questions: What are the odds of a person moving out of the household but within the village in response to extreme temperature or rainfall? What are the odds of a person moving out of the household but out of the village in response to extreme temperature or rainfall?”

New tests seek peace in climate conflict blame game

Researchers are hoping to work out how climate change affects risk of conflicts, such as the one in Somalia in which this tank was destroyed. Image credit: Carl Montgomery, via Flickr Creative Commons license

After researchers last year went through every paper linking climate changes and human violence, finding a strong connection, new findings suggest that one rare study disagreeing used the wrong maths. Kyle Meng from Princeton University in New Jersey and Solomon Hsiang from the University of California, Berkeley, now hope they’ve settled previous conflicts over the climate-conflict link. “We think this allows the community to move forward onto what I believe are the next set of important questions,” Kyle told me. “Why exactly does climatic change affect violence and what can we do to lessen the effects of climate on violence?”

In last year’s paper, Solomon and his Berkeley colleagues Ted Miguel and Marshall Burke brought together 45 sets of evidence spanning 10,000 years. Reanalysing worldwide measurements from scratch they found that 2°C global temperature rise could make conflicts like civil wars more than 50% more common in many parts of the world.

One paper that didn’t fit with their findings had been published in 2010 by Halvard Buhaug at the Peace Research Institute Oslo, Norway. Halvard’s study used the same data as a 2009 paper that found a climate-conflict link in Africa, written in 2009 by a team including Ted and Marshall. However, Halvard used different models indicating that political and economic factors were more important and that climate was ‘not to blame’.

Halvard’s argument revolves around a mathematical ‘robustness check’ into the statistics used by the 2009 paper. Such checks are common in social science, Kyle explained. “However, it is important to note that not all robustness checks are valid,” he said. “In general, robustness checks are designed to examine whether, given a particular outcome, a statistical model may be producing biased results, such as when improper comparisons are being made amongst observations.”