Barcelona just had a week of temperatures above 30℃. It’s a few degrees hotter than the long-term average, but no heatwave. In winter, Spain’s second largest city is typically a mild 15℃ or so. With its climate regulated by warm Mediterranean waters, temperatures rarely drop below freezing.
Is this what the future holds for London? One group of scientists certainly thinks so. In a new study, they have tried to convey the risks of global warming by finding the closest modern-day climates to describe what the future might be like for certain cities. They predict that, for instance, Madrid’s climate in 2050 will be like Marrakech’s climate now, Seattle will resemble San Francisco, Stockholm will feel like Budapest, and that London will become like Barcelona.
It makes sense to focus on cities as they are literally “hot-spots” of climate risk due to their dense populations, concentration of assets and susceptibility to extreme weather. Getting this message across to city managers and vulnerable communities is not always easy.
The researchers gathered data on the background climate of 520 major cities. Nineteen variables, including maximum temperature of the warmest month and precipitation seasonality, were combined using a statistical method that takes account of their relative importance and interrelationships. Equivalent variables for 2050 were obtained from three climate models, which were all programmed to take the optimistic view that emissions will stabilise this century. Present and future city climates were then used to “twin” the most similar metropolises.
Pairing cities in this way is a clever idea. But such like-for-like comparisons are just too simplistic. This is because cities make their own climates according to their unique layouts, building materials, artificial heat sources, amounts of open or green spaces, and types of water feature.
There can be fundamental differences between two cities in these respects. For example, Barcelona has among the highest population densities in Europe, at about 16,000 per square kilometre, more than the 10,000 or so recorded by inner London boroughs. Population density is a useful indicator of both the intensity and level of exposure to the urban heat island – compact cities tend to be hotter cities.
While Barcelona is striving to become a greener city, nearly two-thirds of Greater London is already occupied by gardens, parks and water. Across the city, such spaces provide cool refuges for people and biodiversity. For instance, satellite observations reveal that on a hot summers day Richmond Park – a large space on the western edge of the city known for its deer – can be about 10°C cooler than parts of the more central Southwark, Lambeth and Westminster. Even in these central boroughs, temperatures are chillier along the Thames embankment than just a few hundred metres away. Hence, the multiple micro-climates experienced day-to-day and from place-to-place within a city are not readily characterised by a few summary statistics.
The actual “felt” temperature depends on a host of factors, not least the effect of atmospheric humidity. Conditions can become lethal when dangerous combinations of temperature and humidity are exceeded – something that unfortunately already occurs in cities such as Karachi in Pakistan or Kolkata in India.
Global warming means that 350m more people could be exposed to deadly heat by 2050 – and South Asian mega-cities are in the front-line. However, with 4°C of global warming even New York could become heat stressed. So any assessment of future conditions in global cities should evaluate the combined threat of heat with humidity. According to the Lancet Countdown 2018 Report, threats to human health from heatwaves are becoming more frequent and dangerous.
Despite the above reservations, the new study does alert us to the possibility that over one-fifth of the studied cities could shift to climate conditions hitherto unobserved anywhere on Earth. This applies to cities such as Kuala Lumpur in Malaysia, Libreville in Gabon and Manaus in Brazil, which are all in the tropics.
Extraordinary temperatures are already being experienced within the homes and workplaces of some low income communities of cities such as Accra, Ghana. Trying to visualise how these places might be further stressed by climate change is an important step towards improving the well-being of some of the world’s most vulnerable urban citizens.
RIBA trustees today formally agreed to join the global declaration of an environment and climate emergency at the triannual meeting of RIBA Council members.
At the meeting, which brings together elected trustees to debate and discuss the biggest issues facing the profession, the Institute also committed to developing the RIBA Ethics and Sustainable Development Commission’s action plan and a pledge to support the government’s 2050 net zero emissions target.
RIBA President, Ben Derbyshire, said:
“The climate emergency is the biggest challenge facing our planet and our profession. But to have a significant impact we need to do more than make symbolic statements – we need to turn warm words into impactful actions.
The implementation of a five-year action plan we have committed to today will ensure we are able to benchmark change and evaluate the actions that make most impact.”
The Ethics and Sustainable Development Action Plan will include measurable actions to support a net zero carbon built environment. It will drive change at a national and international level in industry standards and practice; in government and inter-governmental policy and regulation; and in the RIBA’s own carbon footprint.
The RIBA should work to support chartered member practices (in the UK and internationally) enabling them to commit to voluntary reporting of core building performance metrics and to work towards the whole-life net zero carbon standard and standard Post Occupancy Evaluation (POE) reporting metrics when the guidance is available.
RIBA Chief Executive, Alan Vallance said:
“With a background in the meteorological sector I have a deep insight into the impact of climate change and the vast and urgent task ahead of us. RIBA Council’s commitment to the climate emergency declaration is an important moment for the institute and the profession – a catalyst for the further action and change that is needed to ensure that architects and the built environment sector are at the forefront of a zero-carbon future.”
Next steps will include the implementation of a five-year detailed action plan to embed sustainable industry standards and practice and use the RIBA’s influence to improve government and inter-government policy and regulation.
Chair of the RIBA’s Sustainable Futures Group, Gary Clark said:
“The RIBA Sustainable Futures Group welcomes the RIBA Council decision to declare a climate emergency. This is an important first step that formally recognises the scale and urgency of climate change and that as architects we have an obligation to demonstrate leadership for a sustainable future. Now the hard work starts – we only have 11 years to agree and implement a net zero carbon trajectory for new and retrofitted buildings, and infrastructure. The RIBA will be guiding the profession but we must all take action to voluntarily reduce operational emissions and embodied carbon significantly beyond regulation.”
It could one day reduce the need for air conditioning.
Wednesday, June 12, 2019
Researchers at Columbia University are working on a new way to keep buildings cool. They drew inspiration from an unlikely source: a heat-tolerant species of ant called the Saharan Silver Ant. It lives in the scorching desert.
Yu: “They are only active in the middle of the day when the surface of the desert is the hottest.”
In 2015, physics professor Nanfang Yu discovered that this ant’s silvery coating of hair reflects sunlight and radiates heat back to the sky.
Now, he and his colleagues have developed a paint-like material that mimics these functions.
Yu: “So this coating doesn’t heat up under the Sun.”
When applied to a rooftop, it reflects up to ninety-nine per cent of sunlight and emits heat back to the atmosphere.
Yu says that helps cool the building underneath. And it does so far more effectively than white paint, which only reflects certain wavelengths of solar radiation.
Buying carbon credits in exchange for a clean conscience while you carry on flying, buying diesel cars and powering your home with fossil fuels is no longer acceptable or widely accepted. The era of carbon offsets drawing to a close is a 10 Jun 2019 Story of Climate change, especially if we consider that Renewable Energy Now Accounts for 33% of Global Power and that it is on its way to a full 100% within the near future.
Carbon credits are increasingly coming under fire for essentially allowing some to continue on their polluting ways while the rest of us are left scrambling to contain the climate crisis. The Secretary-General of the United Nations is the first to call everyone to action. “We are still not doing enough, nor moving fast enough, to prevent irreversible and catastrophic climate disruption,” he says.
Meanwhile, scientists, activists and concerned citizens have started to voice their concerns over how carbon offsets have been used by polluters as a free pass for inaction.
Carbon offsets schemes were set up to allow the largest polluters who exceed permitted emissions’ levels to fund projects, such as reforestation, that reduce carbon dioxide (CO2) in the air, essentially balancing out their emissions equation.
The types of carbon offset projects that are implemented are diverse. They range from forestry sequestration projects (which remove CO2 from the atmosphere when trees grow) to energy efficiency and renewable energy projects (which reduce future CO2 emissions in the atmosphere).
UN Environment’s operations have been carbon neutral since 2008 thanks, in part, to the purchase of carbon credits. Since then, the organization has also reduced its emissions by 35 per cent. Many organizations and individuals are buying carbon credits to offset the greenhouse gas emissions involved in travel, principally flying.
Carbon offsets are useful while infrastructure and industry make the transition to electric mobility, alternative energy and the new technology necessary for low- and zero-carbon lifestyles. Where there are no viable alternatives in the short term, an offset scheme promises to cancel out the emissions in one place with emission-reducing actions in another.
However, the reality is far from this neat.
Offsets are only part of the answer
The climate crisis is now considered our gravest existential threat. Fifty per cent of climate changing pollutants have been pumped into our atmosphere—from power stations, cars, agriculture—since just 1990, and this amount is growing every second.
If we are serious about averting catastrophic planetary changes, we need to reduce emissions by 45 per cent by 2030. Trees planted today can’t grow fast enough to achieve this goal and reduce by half our current emissions. And carbon offset projects will never be able to curb the emissions growth if coal power stations continue to be built and petrol cars continue to be bought, and our growing global population continues to consume as it does today.
This is not to say that carbon offset projects should stop, quite the opposite. We must continue to plant trees and protect forests and peatlands. Renewable energy and energy efficiency projects are critical and offset schemes play an important role in funding and upscaling them.
What we must look at, though, is how these actions sum up to reflect the true cost of emissions and the urgency of their reduction. The one-for-one model has been proved wrong. If one tonne of sequestered CO2 is the price of one carbon credit, that offset must include not simply the emissions today, but also factor in the missing 45 per cent emissions’ reduction, as well as the future projected increase.
Shoa Ehsani, a UN Environment official who closely tracks UN Environment’s carbon footprint, says carbon offsetting uptake has been slow. “One of the reasons offsets haven’t been selling is because the Kyoto Protocol and Paris Agreement are non-enforceable. The main procurers of offsets are supposed to be nations trying to meet the targets they promised to meet. But they have reneged on their promises and targets. If the nations of the G20, responsible for 81 per cent of total emissions, are to meet targets, offsets remain an important mechanism for them unless they manage a 45 per cent emissions reduction on their own (which would be fantastic).”
A tool for speeding up climate action
Offsets also risk giving the dangerous illusion of a “fix” that will allow our billowing emissions to just continue to grow.
“UN Environment supports carbon offsets as a temporary measure leading up to 2030, and a tool for speeding up climate action,” says UN Environment climate specialist Niklas Hagelberg. “However, it is not a silver bullet, and the danger is that it can lead to complacency. The October 2018 report by the Inter-governmental Panel on Climate Change made it clear that if we are to have any hope of curbing global warming we need to transition away from carbon for good: by travelling electric, embracing renewable energy, eating less meat and wasting less food.
“To secure popular support for decarbonization, the public needs to be informed about the positive effects of emission reductions, their benefits for cleaner air, health and new energy jobs,” he adds. “We should tax carbon, not people. We know fossil fuel subsidies are unfair when non-polluting alternatives are here right now. Making such a huge transition will require all the tools at our disposal, though, and offsets, if examined and applied with clear eyes, can aid the transition where sudden and drastic change might instead set us further back.”
I was invited to speak to a group of teenagers on climate strike in Oxford recently. Like many scientists, I support the strikes, but also find them disturbing. Which I’m sure is the idea.
Today’s teenagers are absolutely right to be up in arms about climate change, and right that they need powerful images to grab people’s attention. Yet some of the slogans being bandied around are genuinely frightening: a colleague recently told me of her 11-year-old coming home in tears after being told that, because of climate change, human civilisation might not survive for her to have children.
The problem is, as soon as scientists speak out against environmental slogans, our words are seized upon by a dwindling band of the usual suspects to dismiss the entire issue. So if I were addressing teenagers on strike, or young people involved in Extinction Rebellion and other groups, or indeed anyone who genuinely wants to understand what is going on, here’s what I’d say.
My biggest concern is with the much-touted line that “the Intergovernmental Panel on Climate Change (IPCC) says we have 12 years” before triggering an irreversible slide into climate chaos. Slogan writers are vague on whether they mean climate chaos will happen after 12 years, or if we have 12 years to avert it. But both are misleading.
As the relevant lead author of the IPCC Special Report on Global Warming of 1.5°C, I spent several days last October, literally under a spotlight, explaining to delegates of the world’s governments what we could, and could not, say about how close we are to that level of warming.
Using the World Meteorological Organisation’s definition of global average surface temperature, and the late 19th century to represent its pre-industrial level (yes, all these definitions matter), we just passed 1°C and are warming at more than 0.2°C per decade, which would take us to 1.5°C around 2040.
That said, these are only best estimates. We might already be at 1.2°C, and warming at 0.25°C per decade – well within the range of uncertainty. That would indeed get us to 1.5°C by 2030: 12 years from 2018. But an additional quarter of a degree of warming, more-or-less what has happened since the 1990s, is not going to feel like Armageddon to the vast majority of today’s striking teenagers (the striving taxpayers of 2030). And what will they think then?
I say the majority, because there will be unfortunate exceptions. One of the most insidious myths about climate change is the pretence that we are all in it together. People ask me whether I’m kept awake at night by the prospect of five degrees of warming. I don’t think we’ll make it to five degrees. I’m far more worried about geopolitical breakdown as the injustices of climate change emerge as we steam from two to three degrees.
So please stop saying something globally bad is going to happen in 2030. Bad stuff is already happening and every half a degree of warming matters, but the IPCC does not draw a “planetary boundary” at 1.5°C beyond which lie climate dragons.
Get angry, but for the right reasons
What about the other interpretation of the IPCC’s 12 years: that we have 12 years to act? What our report said was, in scenarios with a one-in-two to two-in-three chance of keeping global warming below 1.5°C, emissions are reduced to around half their present level by 2030. That doesn’t mean we have 12 years to act: it means we have to act now, and even if we do, success is not guaranteed.
And if we don’t halve emissions by 2030, will we have lost the battle and just have to hunker down and survive? Of course not. The IPCC is clear that, even reducing emissions as fast as possible, we can barely keep temperatures below 1.5°C. So every year that goes by in which we aren’t reducing emissions is another 40 billion tonnes of CO₂ that we are expecting today’s teenagers to clean back out of the atmosphere in order to preserve warm water corals or Arctic ice.
Assuming people will still want to feed themselves and not turn the world over to biofuels, then scrubbing CO₂ out of the atmosphere currently costs £150-£500 per tonne, plus the cost of permanent disposal. So those 40 billion tonnes of CO₂ represent a clean-up liability accumulating at a cool £8 trillion per year, which is more or less what the world currently spends on energy.
So here is a conversation young activists could have with their parents: first work out what the parents’ CO₂ emissions were last year (there are various carbon calculators online – and the average is about seven tonnes of fossil CO₂ per person in Europe). Then multiply by £200 per tonne of CO₂, and suggest the parents pop that amount into a trust fund in case their kids have to clean up after them in the 2040s.
If the parents reply, “don’t worry, dear, that’s what we pay taxes for”, youngsters should ask them who they voted for in the last election and whether spending their taxes on solving climate change featured prominently in that party’s manifesto.
Get angry by all means, but get angry for the right reasons. Action is long overdue, but to a British public sunbathing in February, weird though that was, it doesn’t feel like an emergency. Middle-aged critics would much rather quibble over the scale of climate impacts (as if they have any right to say what climate young people should have to put up with) than talk about the clean-up bill.
Climate change is not so much an emergency as a festering injustice. Your ancestors did not end slavery by declaring an emergency and dreaming up artificial boundaries on “tolerable” slave numbers. They called it out for what it was: a spectacularly profitable industry, the basis of much prosperity at the time, founded on a fundamental injustice. It’s time to do the same on climate change.
Solar geoengineering (also known as solar radiation management) is a technology in its infancy – and it is controversial. It has the potential to reverse or mitigate some of the global warming caused by greenhouse gases by either releasing cooling particles (for instance sulphur) into the stratosphere, or by modifying clouds over the oceans so that they reflect more heat back into space.
But there are major concerns about how politics could influence research and development, and the deployment of solar geoengineering on a global scale. Last year’s special report by the Intergovernmental Panel on Climate Change (IPCC), Global Warming of 1.5 ºC struck a cautionary note: ‘Although some [solar radiation modification] measures may be theoretically effective […], they face large uncertainties and knowledge gaps as well as substantial risks and institutional and social constraints to deployment related to governance, ethics, and impacts on sustainable development.’ One of these risks could be conflict, should a country use geoengineering without global agreement – an action that cause harm to others.
Here we use game theory to better understand these concerns and find out what could happen if countries were able to move the earth’s thermostat in either direction – by using geoengineering technologies to reduce the temperature and counter-geoengineering to turn it back up again.
Solar geoengineering technologies could be cheap. This creates a problem economists call the ‘free-driver effect’. If the cost is not prohibitive, a single nation (or even a single billionaire) could pay to press the button on a geoengineering action that affects the whole planet.
On first impressions it might sound good for a potential global warming fix to be inexpensive and accessible. But a country with an especially strong incentive to cool the planet – one that is suffering badly due to climate change – could go ahead and deploy a technology that will affect us all, effectively taking a unilateral decision on the optimal temperature for the Earth.
Some like it hot(ter)
One idea to counter this ‘free-driving’ effect is to develop counter-geoengineering. While solar geoengineering would cool temperatures, counter-geoengineering might use similar technology to heat the earth up – for example, by injecting short-lived heat-trapping aerosols into the atmosphere, or using a chemical to counteract a sulphate injection.
The possibility of being able to turn the temperature back up might act as a deterrent to free-drivers. Who would want to risk causing an escalation of opposing climate interventions that would only waste resources? The prospect of counter-geoengineering might reintroduce a willingness to collaborate. We tested this possibility using game theory.
The rules of the game
We set up a two-player game. Each player represents a country (or a bloc of countries) and each has a – potentially different – temperature preference for the planet.
It is a two round game. Round 1 is treaty-making. The players can choose to opt into a treaty and collaborate, or they can opt out. There are two treaty options available: the first is a deployment treaty, where countries jointly decide on the climate intervention that maximises the coalition’s overall payoff. The second treaty option is a moratorium treaty, under which the countries commit to abstain from any climate intervention. Whichever decision they make, they will only enter into a treaty if it is in their best interests – all the players are ‘selfish actors’.
Round 2 is deployment, i.e. modifying the global temperature with a climate intervention that is relatively cheap. If the countries entered into a treaty in Round 1, then they either abstain from a climate intervention (opting for the moratorium treaty) or undertake the intervention cooperatively. If no treaty was formed, the players choose their climate intervention levels non-cooperatively.
We played two versions of the game. In one version only solar geoengineering technology was available to the countries – so they could cool the global temperature but not increase it. In the second version they also had access to counter-geoengineering, so they could also turn the temperature up. Comparing the two versions then sheds light on how counter-geoengineering changes the strategic interaction surrounding climate interventions.
The results: arms race or abstinence
The results of the game reveal the importance of the level of agreement over what countries consider the ‘best’ temperature for the planet.
If countries have similar preferred temperatures but do not choose to enter into a treaty, there is a free-rider outcome – countries would benefit from the temperature reduction caused by another country’s geoengineering actions without themselves contributing much to the cost of deployment.
Where countries differ greatly in their preferred temperature, and if counter-geoengineering is not available (which could be because it has not yet been developed), the result is a free-driver outcome, as predicted. The country with the strongest preference for cooling (the free-driver) turns the temperature right down – even if the other prefers it warmer.
In both of these cases, incentives to cooperate are weak.
However, with counter-geoengineering technology on the table the strategic interaction changes, with two outcomes. A country that views the free-driver’s deployment of cooling as excessive now has a tool to counteract it – and will use it. Without the opportunity to cooperate, this results in a ‘climate clash’, an escalation of cooling by geoengineering and warming by counter-geoengineering that has no winners and is very harmful.
However, if cooperation is an option, this bleak outlook may be enough to encourage countries to work together. In particular, the free-driver may be ready to compromise on the amount of climate intervention it makes.
Cooperation is not guaranteed, though, and the outcome might still be a destructive climate clash. Even if countries do cooperate, they may take the moratorium route – and this could be worse than the free-driver outcome if it means the world misses the opportunity to potentially reduce the damage from climate change by using solar geoengineering.
How solar geoengineering and counter-measures could and should be used to adjust the planet’s temperature is subject to widely differing opinions and intense debate. Certainly our study emphasises the crucial need to focus on how any geoengineering interventions could be governed, with the welfare of the majority a central goal. Cooperative decisions including a broad set of actors typically are welcome, but our results also point to the importance of getting the content of a treaty right.
Of course, there are limitations to our analysis, not least the fact that the paper’s main analysis was undertaken in a two-player game, when in reality we could face complex negotiations between many countries. Countries may also want to modify aspects of the climate beyond temperature – especially rainfall patterns. And geoengineering could affect human and ecosystem health, by causing acid rain or ozone depletion – further effects that could cause tensions if one country forged ahead at the expense of others.
Daniel Heyen is a postdoctoral researcher at ETH Zurich. He is an applied theorist working at the interface of decision theory and environmental economics. Daniel’s main research interest is in societal decision-making under uncertainty and learning. Key topics of his work are the description of scientific uncertainty, the design of decision rules, and the analysis of active learning and the value of information. Prior to his position at ETH Zurich, Daniel was a postdoctoral researcher at the Grantham Research Institute, funded through a Fellowship from the German Research Foundation. Daniel completed his PhD in economics at Heidelberg University. His background is in Mathematics and Physics.
Joshua Horton is research director of geoengineering at the Keith Group. Josh conducts research on geoengineering policy and governance issues, including the regulation of research, liability and compensation, and geopolitics. Josh previously worked as a clean energy consultant for a global energy consulting firm. He holds a Ph.D. in political science from Johns Hopkins University.
Juan Moreno-Cruz is an associate professor at the School of Environment, Enterprise and Development and the Canada research chair in energy transitions at the University of Waterloo. He is also a CESifo research affiliate. He has a Ph.D. (2010) from the University of Calgary and a B.A. and M.S. in electrical engineering from the Universidad de Los Andes. Previously, he was an associate professor in the School of Economics at the Georgia Institute of Technology (2011-2017), were he remains as an adjunct professor. He is a visiting researcher in the department of global ecology of the Carnegie Institution for Science at Stanford University, an advisor for Carnegie Energy Innovation, and a research associate of Harvard University’s solar geoengineering research programme.