Counting the true costs of climate change: Impacts World Conference in Potsdam

Counting the true costs of climate change – this is the conference title – is quite a challenge since the social costs in particular are sometimes hard to calculate and also come in terms of human suffering. It is as part of this conference that the Potsdam Institute for Climate Impact Research (PIK) will also celebrate its 25th anniversary, a quarter of a century of advancing insights into the interaction between humankind and the Earth System.

Science shows that limiting global warming is much cheaper than just doing nothing about it – the costs of inaction could in fact be a multiple of the 2 percent of global economic output that mitigation might roughly cost, says Hermann Lotze-Campen, Professor at the Agricultural Economics Department at HU Berlin, chief organizer of the conference, and chair of Research Domain Climate Impacts and Vulnerabilities at PIK. However, these current estimates are still without taking into account the costs of health impacts and additional deaths, of people leaving their homes and potential mass-migration, and of sustained poverty – complex issues we now try to better address scientifically, along with the economic costs and damages. On the one hand, our rather unique meeting of the global impacts research community is all about improving methodologies, which sounds rather abstract; but on the other hand this is the very basis for providing robust information on future risks for farmers, factories, and families.

The conference is organized by PIK and sponsored by the German Federal Ministry of Education and Research. Speakers include scientists such as Hans Otto Pörtner, Co-Chair of Working Group 2 on climate impacts for the next report of the Intergovernmental Panel on Climate Change (IPPC), and Leena Srivastava from TERI, The Energy and Resources Institute in India. But also key stakeholders will attend, like Shardul Agrawala from the OECD (Organisation for Economic Co-Operation and Development) or Andrea Tilche from the European Commission's DG Research and Innovation. The session celebrating 25 years of PIK features the Prime Minister of the State of Brandenburg, Dietmar Woidke, Patricia Espinosa, Executive Secretary of the United Nations Framework Convention on Climate Change (UNFCCC), and other high-ranking speakers.

Migration: The people who have to leave their homes
Climate change is a central issue of human welfare and sustainable development — the 'costs' of climate change can feel highest for the people who have to leave their homes, says Koko Warner who's an expert on migration issues at the United Nations Framework Convention on Climate Change (UNFCCC). In all cases of human mobility — displacement from storms, the scramble for climate-proof livelihoods, or the search for habitable places when return to homelands isn't possible anymore — climate change requires a new level of resilience.

Climate change impacts such as droughts may also contribute to fuel already smoldering local conflicts and, in some cases, trigger the outbreak of violence.

Countries of origin, transit, and destination will need to join efforts to bolster resilience through a continuum of approaches, says Warner. First, there is a pressing need to preempt climate impacts and expand adaptation options for people worldwide. Second, plans are needed for mobility that is safe, dignified, and regular when it occurs for areas of origin, transit countries, and areas of destination. Third, areas of origin and destination will need contingency arrangements to share the burden of transitions, which may include longer-term changes in where and how people live.

Economic costs: More than just dollars
It's more than just dollars, says Stéphane Hallegatte from the World Bank, one of the speakers at the conference. When asked about the cost of climate change, people too often focus on an absolute amount, in dollars or percent of GDP. This conference calls for a more comprehensive assessment of the impacts of climate change, looking at multiple dimensions like poverty and inequality. Its conclusions will help inform policymakers who need to design today the policies that will protect tomorrow's populations and economies.

Economic costs do not only include damages for instance from weather extremes, which can spread through global supply chains, but also productivity reductions due to heat stress for workers.

Health: Heat-related deaths, Yellow Fever, reductions in crop yields
Climate change is a growing threat to human health through a range of pathways, says Andy Haines from the London School of Hygiene and Tropical Medicine, Great Britain, also one of the speakers at the conference. For example, in the absence of deep cuts in greenhouse gas emissions increasing exposure to extreme heat is likely to affect hundreds of millions of people by mid-century, such that formerly rare heat events become a regular occurrence. Preliminary results of large multi-country analyses indicate that increased heat-related deaths will greatly exceed reductions in cold-related mortality in some regions, in particular warmer and poorer areas that are projected to include a substantial part of the global population. In addition, in these regions the increased heat exposure will progressively reduce the ability to work outdoors.

Climate change will also affect the incidence and distribution of vector-borne diseases, for example those transmitted by mosquitoes, adds Haines. Numbers of cases of the common vector-borne disease Dengue have doubled every decade since 1990 and climate change has been suggested as one potential contributor to this increasing burden. The principal mosquito vectors of Dengue also carry other important emerging or re-emerging virus diseases, including Yellow Fever, Chikungunya and Zika viruses, which are also likely to be affected by climate change.

Reductions in crop yield and changes in nutritional quality due to climate and other environmental changes also pose serious threats to health, particularly to populations living in tropical regions, stresses Haines. Preliminary analyses demonstrate that these impacts can be substantially reduced under scenarios of lower emissions of greenhouse gases and reduced global warming. In fact, there are also major opportunities to reduce the emissions whilst improving health in the near term, for example as a result of reductions in air pollution from increased use of clean renewable energy, increased consumption of healthy and more sustainable diets and increased physical activity from sustainable transport policies. Recognition and valuation of these co-benefits to health can incentivize the implementation of policies for climate change mitigation and thus reduce the risks of exposure to dangerous climate change.

Sustainable Development: Eradicating hunger implies limiting global warming
The science is now clear, attaining the Paris climate agreement of reducing human caused global warming to under 2 C is necessary to stand a chance of succeeding with the UN Sustainable Development Goals (SDGs) to eradicate hunger and poverty and enable economic development and good lives for all citizens in the world, says Johan Rockström from Stockholm University, also one of the speakers at the conference. Climate risks are so high, they may undermine world development. But the reverse is also true. Attaining the SDGs, which entails a world transformation to global sustainable development, is necessary to succeed with the Paris climate agreement. This means we have no choice. Global sustainability is our path to the future.

For further information on the Impacts World Conference and full programme click here.