Mercator Research Institute on Global Commons and Climate Change
Mercator Research Institute on Global Commons and Climate Change
News Article | May 4, 2017
Carbon pricing in the G20: A window for advancing sustainable development In this article, the author makes the case for carbon pricing as a mechanism to fortify flimsy nationally determined contribution (NDC) plans, steer investments in the right direction and ultimately curb emissions. The author suggests that carbon pricing should not only be considered in the narrow context of climate protection, but in the broader context of the sustainable development goals (SDGs). The leadership of Angela Merkel can provide a good chance for a push towards implementing carbon pricing in the G20 context. The increase in global greenhouse gas emissions will not be stopped through the implementation of the nationally determined contributions (NDCs) under the Paris Agreement; the growth up to 2030 will just be a little slower. In fact, the combined effect of all mitigation pledges would still be insufficient even if they were adequately implemented. Moreover, only a few out of 150 countries submitted concrete policies and implementation plans for their intended national contributions, leading to considerable uncertainty. It is of utmost importance to back the rather vague and loose intentions of the NDCs with substantive instruments. An effective instrument to steer investments in the right direction and ultimately curb emissions would be a price on carbon, either through a tax or a functioning emissions trading system. Since the industrial revolution, economic development has been largely based on the consumption of fossil fuels. But in order to mitigate climate change, it is crucial to separate economic growth from emissions growth. Despite the fact that renewables are on the rise in several industrialised economies, many countries are still relying on the use of coal, which stands by far as the world’s cheapest source of energy. There is also an abundant supply of fossil fuels still available in the ground. If we want to achieve the two-degree target with high probability, the atmosphere can only absorb another 800 gigatons of carbon dioxide (CO2) in total. However, the Earth still harbours about 15,000 gigatons of CO2 in the form of fossil fuels. This means that at least 40 percent of the Earth’s oil, 40 percent of the gas and, especially, 80 percent of the coal will have to remain in the ground. Nonetheless, the use of coal, oil and gas is subsidised on a global scale with an estimated US$150 per ton of CO2, if all externalities, such as negative health impacts, are included. Thus, the political and economic challenges are immense. As a first step, huge progress could be made by dismantling the exorbitant coal subsidies, as has been shown by the Mercator Research Institute on Global Commons and Climate Change (MCC). According to recent MCC research, this measure alone could grant universal access to drinking water to people in 70 countries of the world, sanitation to 60 countries and electricity to 50 countries over the course of the next 15 years — provided that the money presently going to coal subsidies is diverted to the construction of these infrastructures. At the same time, this measure would function as a poverty alleviation programme. Climate change mitigation will only be successful if a “just transition” is ensured where emerging economies can be assured that this will not hinder their development. This means carbon pricing should not only be considered in the narrow context of climate protection, but in the broader context of the sustainable development goals (SDGs), adopted by all 193 UN members states in 2015. The industrialised countries would likewise benefit from carbon pricing. In particular the finance ministers — even if they do not care much about climate policy — stand to benefit from this regime. Similar to an eco tax, a carbon tax can be used, for example, to lower other taxes, such as income taxes or capital gains taxes. It could also be used to improve the public transport system. What role for the G20? A suitable forum for promoting carbon pricing internationally would be the group of the 20 major economies (G20). The G20 countries are responsible for roughly 80 percent of global emissions and are thus heavyweight players in climate policy. In addition, they have all submitted their NDCs and 18 of them have already ratified the Paris Agreement. The current political climate appears more favourable than ever to the introduction of a carbon price, not least with the announcement by China — the largest emitter of greenhouse gases — that it will launch the world’s largest emissions trading scheme in 2017. Together with Europe, the People’s Republic could create the world’s largest carbon market. Were this to happen, the turnaround of international climate policy would be as irreversible as climate change is today. In the end, 2017 could be a starting point for the achievement of new milestones in climate protection. Under the leadership of Angela Merkel there is a good chance for a push towards implementing carbon pricing in the G20 context. This would allow the world to pursue a path of growth that both protects the environment and lifts people out of poverty. Prof. Ottmar Edenhofer is the director of the Mercator Research Institute on Global Commons and Climate Change (MCC), chief economist at the Potsdam-Institute of Climate Impact Research (PIK) and Professor of the Economics of Climate Change of the Technical University Berlin.
Plevin R.J.,University of California at Davis |
Delucchi M.A.,University of California at Davis |
Creutzig F.,Mercator Research Institute on Global Commons and Climate Change |
Creutzig F.,TU Berlin
Journal of Industrial Ecology | Year: 2014
Summary: Life cycle assessment (LCA) is generally described as a tool for environmental decision making. Results from attributional LCA (ALCA), the most commonly used LCA method, often are presented in a way that suggests that policy decisions based on these results will yield the quantitative benefits estimated by ALCA. For example, ALCAs of biofuels are routinely used to suggest that the implementation of one alternative (say, a biofuel) will cause an X% change in greenhouse gas emissions, compared with a baseline (typically gasoline). However, because of several simplifications inherent in ALCA, the method, in fact, is not predictive of real-world impacts on climate change, and hence the usual quantitative interpretation of ALCA results is not valid. A conceptually superior approach, consequential LCA (CLCA), avoids many of the limitations of ALCA, but because it is meant to model actual changes in the real world, CLCA results are scenario dependent and uncertain. These limitations mean that even the best practical CLCAs cannot produce definitive quantitative estimates of actual environmental outcomes. Both forms of LCA, however, can yield valuable insights about potential environmental effects, and CLCA can support robust decision making. By openly recognizing the limitations and understanding the appropriate uses of LCA as discussed here, practitioners and researchers can help policy makers implement policies that are less likely to have perverse effects and more likely to lead to effective environmental policies, including climate mitigation strategies. © 2013 by Yale University.
News Article | November 10, 2016
Climate change is one of the most pressing concerns of the 21st century. But when it comes to tackling climate change, a new study from Cogent Economics & Finance exploring the benefits of carbon flux monitoring is a timely reminder that setting targets is just the beginning. Now that the Paris Agreement has decreased the level of carbon emissions deemed acceptable, the need for a decarbonised energy sector is greater than ever. Although technology exists to monitor actual carbon fluxes globally, the systems currently used to do it are expensive at a time when public financial resources are stretched. In pursuit of this, clean technologies must be supported while fossil fuels are penalised, yet uncertainty in the price of carbon makes it difficult to set caps and impose financial penalties. It also makes it challenging to create a stable, socially desirable investment environment that fosters carbon-neutral technologies. To that end, this article investigates the many ways in which better observation of actual carbon fluxes can aid environmental policy, economic investment and informed decision-making. The study found that better monitoring systems could bring significant cost savings and other benefits, thereby encouraging investors and paving the way for achieving ambitious climate change targets. The study is the result of a collaboration of researchers from several institutes, namely the International Institute for Systems Analysis, the Mercator Research Institute on Global Commons and Climate Change, The Inversion Lab, Lund University, Fondazione Eni Enrico Mattei, Comenius University, Lviv Polytechnic National University, the Euro-Mediterranean Center on Climate Change (CMCC Foundation) and the Max-Planck-Institute for Biogeochemistry. The authors come from a variety of academic backgrounds, exploring topics in economics, mathematics, remote sensing, forestry, physics, biogeochemistry, integrated assessment of climate change and climate change mitigation.
News Article | November 25, 2015
The year is 2100 and the world looks nothing like it did when global leaders gathered for the historic climate summit in Paris at the end of 2015. Nearly 8.8 billion people now crowd the planet. Energy consumption has nearly doubled, and economic production has increased more than sevenfold. Vast disparities in wealth remain, but governments have achieved one crucial goal: limiting global warming to 2 °C above pre-industrial temperatures. The United Nations meeting in Paris proved to be a turning point. After forging a climate treaty, governments immediately moved to halt tropical deforestation and to expand forests around the globe. By 2020, plants and soils were stockpiling more than 17 billion tonnes of extra carbon dioxide each year, offsetting 50% of global CO emissions. Several million wind turbines were installed, and thousands of nuclear power plants were built. The solar industry ballooned, overtaking coal as a source of energy in the waning years of the twenty-first century. But it took more than this. Governments had to drive emissions into negative territory — essentially sucking greenhouse gases from the skies — by vastly increasing the use of bioenergy, capturing the CO generated and then pumping it underground on truly massive scales. These efforts pulled Earth back from the brink. Atmospheric CO concentrations peaked in 2060, below the target of 450 parts per million (p.p.m.) and continue to fall. That scenario for conquering global warming is one possible — if optimistic — vision of the future. It was developed by modellers at the Joint Global Change Research Institute in College Park, Maryland, as part of a broad effort by climate scientists to chart possible paths for limiting global warming to 2 °C, a target enshrined in the UN climate convention that will produce the Paris treaty. Climate modellers have developed dozens of rosy 2 °C scenarios over several years, and these fed into the latest assessment by the Intergovernmental Panel on Climate Change (IPCC). The panel seeks to be policy-neutral and has never formally endorsed the 2-degree target, but its official message, delivered in April 2014, was clear: the goal is ambitious but achievable. This work has fuelled hope among policymakers and environmentalists, and it will provide a foundation for debate as governments negotiate a new climate agreement at the UN’s 2015 Paris Climate Conference starting on 30 November. Despite broad agreement that the emissions-reduction commitments that countries have offered up so far are insufficient, policymakers continue to talk about bending the emissions curve downwards to remain on the path to 2 degrees that was laid out by the IPCC. But take a closer look, some scientists argue, and the 2 °C scenarios that define that path seem so optimistic and detached from current political realities that they verge on the farcical. Although the caveats and uncertainties are all spelled out in the scientific literature, there is concern that the 2 °C modelling effort has distorted the political debate by obscuring the scale of the challenge. In particular, some researchers have questioned the viability of large-scale bioenergy use with carbon capture and storage (CCS), on which many models now rely as a relatively cheap way to provide substantial negative emissions. The entire exercise has opened up a rift in the scientific community, with some people raising ethical questions about whether scientists are bending to the will of politicians and government funders who want to maintain 2 °C as a viable political target. “Nobody dares say it’s impossible,” says Oliver Geden, head of the European Union Research Division at the German Institute for International and Security Affairs in Berlin. “Everybody is sort of underwriting the 2-degree cheque, but scientists have to think about the credibility of climate science.” Modellers are first to acknowledge the limits of their work, and say that the effort is designed to explore options, not predict the future. “We’ll tell you how many nuclear power plants you need, or how much CCS, but we can’t tell you whether society is going to be willing to do that or not,” says Leon Clarke, a senior scientist and modeller at the Joint Global Change Research Institute. “That’s a different question.” The idea of limiting global warming to 2 °C dates back to 1975, when economist William Nordhaus of Yale University in New Haven, Connecticut, proposed that more than 2 or 3 degrees of warming would push the planet outside the temperature range of the past several hundred thousand years. In 1996, the EU adopted that limit, and the Group of 8 (G8) nations signed on in 2009. The parties to the UN convention on climate change affirmed the target in 2009 at their Copenhagen summit, and then formally adopted it a year later in Cancún, Mexico. The move caught scientists off guard. Before 2009, most modellers had focused on scenarios in which atmospheric CO concentrations stabilized around 550 p.p.m. — double the pre-industrial level — which would probably limit warming to a little less than 3 °C. But as political interest in the 2 °C target grew, a few started exploring the implications. In April 2009, a team led by Myles Allen, a climate scientist at the University of Oxford, UK, published1 a study concluding that humans would have to limit their total cumulative carbon emissions to 1 trillion tonnes — more than half of which had already been dumped into the atmosphere — to maintain a chance of limiting warming to 2 °C. This trillion-tonne carbon budget provided a scientific baseline for what was now a politically important target, and many modellers shifted gears. “There were very few scenarios with stringent targets such as 2 °C, and then sponsors started demanding it,” says Massimo Tavoni, deputy coordinator of climate-change programmes at the Eni Enrico Mattei Foundation in Milan, Italy. The flurry of modelling efforts that followed split into two main camps: pay early or pay late (see ‘Two paths to 2 °C’). In the former, nations need to slash greenhouse-gas emissions immediately; in the latter, they can buy time for a slower phase-out by developing a massive infrastructure to suck CO out of the air. “Models that have these negative emissions really do let you continue to party on now, because you have these options later,” says John Reilly, co-director of the Joint Program on the Science and Policy of Global Change at the Massachusetts Institute of Technology (MIT) in Cambridge. In the pay-later approach, most models rely on a combination of bioenergy and CCS. The system starts with planting crops that are harvested and either processed to make biofuels or burnt to generate electricity, which provide carbon-neutral power because the plants absorb CO as they grow. The CO created when the plants are processed is captured and pumped underground, and the process as a whole eats up more emissions than it creates. A consortium sponsored by the US Department of Energy has tested such a system at one facility that produces bioethanol fuel in Illinois, but neither bioenergy nor CCS has been demonstrated on anywhere near the scales imagined by the models. “It’s just simple arithmetic: the carbon budget is so small that you need to go negative, or at least you need to offset some of your emissions in order to get to zero,” says Tavoni. “We tried to be honest, and pretty agnostic about whether these transformations are easily achievable.” On the basis of those models and other information, the IPCC estimates that climate mitigation would reduce the projected global consumption in 2100 by 3–11% — a relatively modest amount that would allow the global economy to keep growing overall. But remove either bioenergy or CCS from the scenarios and the costs increase substantially. If mitigation is delayed or bioenergy and CCS are constrained, most models simply can’t limit warming to 2 °C. The question is whether any of those models accurately reflect technical and social challenges. MIT has a model that tends to project costs two or three times the average reported by the IPCC, in part because it tries to reflect difficulties in scaling up any technology, such as the availability of skilled labour and natural resources in different regions. And then there are the technical hurdles. Capturing CO from power plants has proved more difficult and expensive than many had hoped. Just one commercial project is currently operating, at the Boundary Dam Power Station in Saskatchewan, Canada. Moreover, Reilly says, the number of models that actually completed 2 °C scenarios remains relatively small, and they probably project lower mitigation costs than those that are not able to generate these low-emissions scenarios. “It’s a very self-selecting set of models.” Although the caveats are listed in the IPCC assessment, the report does not adequately highlight economic and technical challenges or modelling uncertainties, says David Victor, a political scientist at the University of California, San Diego, who participated in the IPCC assessment. Victor does not place all the blame on scientists glossing over the problems: when researchers drafted the assessment’s chapter on emissions scenarios and costs, he says, they included clear statements about the difficulty of achieving the 2 °C goal. But the governments — led by the EU and a bloc of developing countries — pushed for a more optimistic assessment in the final IPCC report. “We got a lot of pushback, and the text basically got mangled,” Victor says. For all of the concerns and criticisms, however, modellers say that the exercises have illuminated important research questions, such as how much bioenergy and CCS will cost and what effects they will have on land use, food systems and water availability. One 2014 study2 in Earth’s Future, for instance, found that it would be difficult to grow enough bioenergy crops, even with second-generation cellulosic biofuels, which are made not only from a plant’s sugars but also from the carbon in its stem and woody materials. The effort would require significant boosts in crop yields and the use of 77% more nitrogen fertilizer by 2100. The bioenergy would also need to be produced in centralized facilities that capture the bulk of the emissions. Unless everything goes right, scaling up to the level projected in many models would be difficult without significantly reducing food production or clearing large swathes of natural ecosystems for farmland. “If we need to ramp up such a large infrastructure, we need to investigate what that implies,” says Sabine Fuss, an environmental scientist at the Mercator Research Institute on Global Commons and Climate Change in Berlin. Fuss led a commentary3 in Nature Climate Change in October 2014 calling for a transdisciplinary research agenda on negative emissions. One of the first outgrowths of that work, led by co-author Peter Smith, a biologist at the University of Aberdeen, UK, is an upcoming assessment of carbon-negative strategies and potential limitations. Strategies include bioenergy with CCS, as well as other ways of absorbing carbon, such as planting forests, using chemical scrubbers to capture CO directly from the air and crushing rocks to enhance geological weathering that consumes the gas. “The science behind these technologies is probably a bit behind the models,” Smith says. “This sort of provides a road map for where we need to go in the next two or three years.” Modellers are also digging into real-world complexities. Most models assume that participation in climate mitigation will be global, that countries will put a common price on carbon, that technological solutions will be widely available and that this combination will drive investment towards relatively cheap mitigation options in developing nations. But the reality could be more complicated. A team at the Joint Global Change Research Institute worked with Victor and others to investigate the risks of making investments in developing countries due to political instability and the relatively poor quality of many public institutions there. Their model showed4 that investors would probably shun developing countries and pour money into developed ones, driving up costs and making it harder to curb rapidly rising emissions in developing nations. “The models have taught us that with unrealistic assumptions anything is possible, and with realistic assumptions it will be very hard to cut emissions to meet goals like 2 degrees,” Victor says. “That’s an important result because it forces — or should force — some sobriety about what can be achieved.” One message that modellers have delivered quite clearly is that without collective and aggressive action by all countries, costs invariably increase, and the chance of hitting the 2 °C goal plummets. This is precisely the situation heading into the Paris summit. Most countries, and all of the major greenhouse-gas emitters, have submitted pledges to reduce their emissions, but these vary widely in ambition. As it stands, the world is on a path to nearly 3 °C of warming by the end of the century, and even that assumes substantial emissions reductions in the future. If nations do not go beyond their Paris pledges, the world could be on track to use up its 2 °C carbon budget as early as 2032. If the models are correct, world leaders may have to either accept extra warming or plan for a Herculean negative-emissions campaign. In the event that they choose the latter — and succeed — the entire debate will change. “It’s a completely different game,” says Nebojsa Nakicenovic, an economic modeller and deputy director-general of the International Institute for Applied Systems Analysis in Laxenburg, Austria. “If that is technically possible, then we could also go below 2 degrees.” Fast-forward to 2100 once more. The bioenergy industry is now one of the largest and most powerful on Earth. People are pulling roughly as much CO out of the atmosphere as they were emitting at the time of the historic Paris conference. Humanity has asserted control over the atmosphere, and governments face a new and difficult question at the 108th anniversary of the UN climate convention: how low should they set the global thermostat?
News Article | October 25, 2016
« Large-scale study finds long-term exposure to air pollution linked to high blood pressure | Main | Rice University scientists find O-doped boron nitride-graphene hybrid excellent candidate for on-board hydrogen storage » Recently appointed by The Volkswagen Group’s Sustainability Council, recently appointed and comprising nine members from several nations—including Margo Oge, former director of the US Environmental Protection Agency (EPA) Office of Transportation Air Quality—set the agenda for its work at its inaugural meeting on Monday. The Council elected Georg Kell, Founding Director UN Global Compact, as its chair. The first areas of focus in 2017 for the body will be the challenges of global CO emissions and the corresponding regulations post-2025, plus the company’s transformation process. The Volkswagen Group is proactively making €20 million (US$21.75 million) available for the first two years for the proposal and funding of projects. The Volkswagen Sustainability Council will be equipped with far-reaching information and consultation rights, as well as rights to operate on its own initiative. It will advise the Management Board on matters of business ethics and integrity, as well as on central issues facing the automotive industry in the future, such as the transformation from car manufacturer to mobility services provider, on the radical technological change from internal combustion engine to electric mobility and on the question of finding a balance between profitability, good jobs and environmental protection. —Matthias Müller, Chairman of the Board of Management of the Volkswagen Group In today’s inaugural meeting we have already experienced a very intense and open discussion. We are fully aware of the large transformation that lays ahead Volkswagen Group. We were invited to be part of this journey and are very much looking forward on being actively involved in the development of this journey. The members of the Group’s Sustainability Council are: Prof. Dr. Ottmar Edenhofer – Deputy Director of the Potsdam Institute for Climate Impact Research, Director of the Mercator Research Institute on Global Commons and Climate Change. Prof. Dr. Gesche Joost – Professor at the University of the Arts in Berlin. Yves Leterme – former OECD Deputy Secretary-General and former Prime Minister of Belgium. Prof. Dr. Gertrude Lübbe-Wolff, former Judge at the Federal Constitutional Court Margo T. Oge, former Director of Transportation Air Quality, US Environmental Protection Agency (EPA). Oge led the EPA’s first national greenhouse gas emission standards for cars and heavy-duty trucks to double fuel efficiency by 2025 and reduce GHG emissions by 50%. Michael Sommer, former President of the Confederation of German Trade Unions (DGB). Elhadj As Sy, Secretary General of the International Federation of Red Cross and Red Crescent Societies (IFRC). The Group’s Sustainability Council will in future not only convene with Members of the Board of Management but will also intensively interact with the General Works Council as well as with different departments within the Group and its brands in workshops, meetings and discussions.
News Article | April 4, 2016
A sand berm created by city workers to protect houses from El Nino storms and high tides is seen at Playa Del Rey beach in Los Angeles, California on November 30, 2015 (AFP Photo/Mark Ralston) More Paris (AFP) - Trillions of dollars' worth of financial assets may be under threat from global warming's effects by 2100, climate economists warned on Monday. If warming reaches 2.5 degrees Celsius (4.5 degrees Fahrenheit) over pre-Industrial Revolution levels by 2100, investments worth some $2.5 trillion (2.2 trillion euros) may be in danger, a team reported. This was equal to half the current estimated stock market value of fossil-fuel companies. But even if the 2 C warming agreed by the world's nations in Paris last December is achieved, the value of assets at risk would be $1.7 trillion, they wrote in the journal Nature Climate Change. Climate change can destroy assets directly through sea-level rise for example, by depreciating their value, or by disrupting economic activities lower down the chain through drought or freak storms. A lot of research has focused on the oil, coal and gas investments that will be lost if the world turns its back on fossil fuels in favour of sustainable energy in line with the 2 C target. The new study attempts to break new ground with the first-ever estimate of a direct impact of climate change on the value of financial assets themselves. The projections, using mathematical models, were based on an estimated value of $143.3 trillion for global non-bank financial assets in 2013, as determined by the Financial Stability Board watchdog, the team said. At warming of 2.5 C, they wrote, some 1.8 percent of global financial assets could be at risk. But this could rise to as much as $24 trillion in worst-case-scenario warming. Scientists estimate we are on course for warming of about 4 C or more based on current greenhouse gas emission trends, or about 3 C if nations meet the emissions-curbing pledges they filed to back up the Paris climate agreement. "When we take into account the financial impacts of efforts to cut emissions, we still find the expected value of financial assets is higher in a world that limits warming to 2 C," said co-author Simon Dietz of the Grantham Research Institute on Climate Change. "This means risk-neutral investors would choose to cut emissions, and risk-averse investors would be even more keen to do so." Climate change should be an important issue for all long-term investors, such as pension funds, as well as financial regulators, added Dietz. Sabine Fuss of the Mercator Research Institute on Global Commons and Climate Change in Berlin, said it was not the final word on the topic, but the study did demonstrate that climate risks to the financial system may be substantial. "This undermines both the need for full disclosure so that climate risks can be assessed and portfolios adjusted accordingly, and the need for more research to develop comprehensive estimates of the risk of such losses," she wrote in a comment published by the same journal.
Creutzig F.,Mercator Research Institute on Global Commons and Climate Change
Urban Climate | Year: 2014
Urban form and transportation infrastructure mutually influence each other. For example, dense Hong Kong is served by a viable and efficient public transit network, whereas many sprawled US cities are best served with automobiles. Here we present a simple model of a mono-centric city with two modes, public transit and automobiles, and transport infrastructure investments. The contribution to the literature is two-fold. First, adding to urban economic theory, we analyze how public transport costs are endogenously determined by fuel price and urban form if an urban planner provides the infrastructure. But a private mass transport provider would underinvest into public transport infrastructure. Second, adding to the ongoing discussion on urban transport and energy use, this two-modal model can help to explain empirical observations on urban form, transport CO2 emissions and modal share, emphasizing the causal role of transport costs for urban form. The results encourage further research in the economics of sustainable and energy-efficient cities. © 2014 Elsevier B.V.
Lamb W.F.,Mercator Research Institute on Global Commons and Climate Change
Journal of Cleaner Production | Year: 2016
This paper explores the underlying development outcomes and cumulative emissions trajectories of 20 middle-income countries from Eastern Europe, Latin America, North Africa and South Asia. First, well-being outcomes are assessed, defined in terms of access to education, democratic and legal rights, and the infrastructures that support physical health. Second, emissions trajectories are estimated to 2050, taking into account current trends in energy consumption and carbon intensity, a likely start-date for stringent climate policy arising from the Paris Agreement (2020), and maximum feasible rates of mitigation. Comparing these estimates to a per capita allocation from the global carbon budget associated with 2 °C, ten countries have low-carbon development trends that will not exceed their allocation. Of these, Costa Rica and Uruguay are achieving very high well-being outcomes, while many more are delivering good outcomes in at least two domains of human need. However, most are seriously deficient in terms of social well-being (education, democratic and legal rights). These results call into question the socio-economic convergence of developing countries with industrialised countries; but they also reaffirm the low-emissions cost of extending good infrastructure access and physical health outcomes to all, demonstrated by the existence of multiple countries that continue to avoid carbon-intensive development. © 2016 Elsevier Ltd.
Creutzig F.,Mercator Research Institute on Global Commons and Climate Change
Environmental Research Letters | Year: 2015
The beauty of cities is that every city is different. From the homogenizing perspective of global environmental change that speaks trouble. We need an understanding of which kind of cities can contribute what kind of measures to mitigate and adapt to global environmental change. Typologies of cities offer a bridge between the idiosyncratic and the global. Bounoua et al (2015 Environ. Res. Lett. 10 084010) analyse the impact of urbanization on surface climate. We discuss their results and suggest avenues for further systematic analysis. © 2015 IOP Publishing Ltd.
News Article | December 27, 2016
Our future crops will face threats not only from climate change, but also from the massive expansion of cities, a new study warns. By 2030, it’s estimated that urban areas will triple in size, expanding into cropland and undermining the productivity of agricultural systems that are already stressed by rising populations and climate change. Roughly 60% of the world’s cropland lies on the outskirts of cities—and that’s particularly worrying, the report authors say, because this peripheral habitat is, on average, also twice as productive as land elsewhere on the globe. “We would expect peri-urban land to be more fertile than average land, as mankind tends to settle where crops can be produced,” says Felix Creutzig from the Mercator Research Institute on Global Commons and Climate Change in Berlin, and principal author on the paper. “However, we were ignorant about the magnitude of this effect.” The agricultural losses they calculated in the study, published in Proceedings of the National Academy of Sciences, translates to a 3 to 4% dip in global agricultural production. This may not appear to be a huge figure at first glance, but on the regional scale the picture changes. Across countries and different crops, the effects of this loss vary and become more intense. In Africa and Asia especially—which together bear 80% of the projected loss due to rising urbanisation in these regions—urban expansion will consign farmers to an even tougher agricultural reality. To arrive at the estimates, the researchers combined datasets on cropland location, productivity, and projected urban expansion by 2030. By superimposing these layers of information on one other, they could highlight the locations where cropland and urban spread are expected to intersect in the future. These projections reveal hotspots of loss in countries like Egypt, Nigeria, the countries that flank Lake Victoria in East Africa, and in Eastern China. (China alone is expected to experience one-quarter of the global cropland loss.) A major worry surrounding the disappearance of this productive land is the impact it will have on staple crops such as maize, rice, soya beans, and wheat, which are cornerstones of global food security. Many of these crops occur in areas that will be consumed by urban spread in years to come. “Due to urbanisation in Nigeria, 17% of rice production and 12% of maize production will be hampered,” Creutzig says. “Egypt will lose more than 40% of its rice, and more than 60% of its maize.” In Africa, there will a 26% continental loss of wheat. Rice is forecast to suffer the most, with a 9% global decline, occurring predominantly in Asia where the bulk of this crop grows. Creutzig notes that some of this loss can be compensated for by agricultural expansion and intensification. But again, this isn’t possible everywhere on the planet: many regions are already limited by their inability to adapt to urban encroachment. For instance, in South Asia farmland can’t simply spread elsewhere, because fertile land is already running out. In India, agricultural expansion would force crops into habitats like wetlands that act as important buffers against flooding and sea-level rise. And in North Africa, worsening conditions driven by climate change will make the land that is available less suitable for farming. “Urbanisation pressure adds to other stresses on the food system, notably climate change,” Creutzig says. This will undermine food security, with countries worst affected by urban expansion experiencing rising dependence on imports. That will leave them vulnerable to global fluctuations in food supply, and could also price crops out of reach of poorer populations. Creutzig sees other subtler food security impacts at play as well—like the ousting of millions of smallscale farmers, as cities expand. These farmers produce the majority of food in developing countries—and so are instrumental to global food security. “As peri-urban land is converted, smallholders will lose their land,” he says. “The emerging mega-cities will rely increasingly on industrial-scale agricultural and supermarket chains, crowding out local food chains.” “In cases where farmers have no formal land rights, such as in Africa, governments may expel farmers from their land,” commented Anton Van Rompaey, a geographer from the Katholieke Universiteit Leuven in Belgium, who was not part of the study but has has done research on urban spread and its agricultural impacts in China. “In the past this has led to social instability and deadly conflicts between farmers and government.” Facing this disturbing future food map, Creutzig predicts that growing food within the city’s margins—urban farming—could be part of the solution. “Urban agriculture is of course utterly insufficient to feed the urban population, but it is very important to maintain local supply chains and provide livelihoods and subsistence for urban farmers,” he says. However, regulations on expansion, to keep urbanisation as compact as possible, will be the bigger prerogative of cities, Creutzig says. After the COP22 climate conference in November this year, there was a call to shift power from the national level to cities, which will be key players in curbing emissions and fighting global climate change. With croplands on the periphery of these urban hubs in peril, ensuring food security is set to become an important part of that mandate, too.