Extracts from the Report issued by the Asian Development Bank in 2017 under a Creative Commons license. See https://www.adb.org/publications/region-at-risk-climate-change for the full report.
The historic Paris Agreement of 2015 has acknowledged that the global climate crisis is arguably the greatest challenge human civilization faces in the 21st century. In this context, the role of the Asia and Pacific region is characterized by a double dichotomy that entails simultaneously high risks and significant opportunities. Proper analysis guided by adequate information can result in investment and policy choices that will continue to promote sustainable economic development and eradicate poverty in the region.
The first dichotomy relates to the region accounting for an increasing overall share of global emissions of greenhouse gases (GHGs) harming not only the world but the region itself. At the same time however, countries of the region have the unprecedented opportunity to break the GHG-intensive development path by rapidly modifying the historical model of industrial development. The rapidly decreasing costs of wind and solar power generation clearly indicates that consumption and production of the future could be driven by renewable energy sources, though the when and where of this great transition remain uncertain.
The second dichotomy pertains to the already observed and anticipated future impacts of anthropogenic global warming. On the one hand, the rapid economic and human development of the region renders societies less vulnerable to the familiar vagaries of the environment—such as heat waves, heavy precipitation or tropical cyclones. In particular, the shift away from agriculture as the core sector guaranteeing livelihoods and the associated economic diversification of the countries of the region help to increase resilience to weather extremes such as those experienced historically. Simultaneously however, the same developments have opened up new avenues of exposure and vulnerability. Coastal populations and assets are highly at risk from projected rises in sea level and the intensification of extreme weather events. Urbanized populations are exposed to heat stress hazards. National and increasingly integrated regional economic systems are vulnerable to disruptions in supply chain networks. Populations are migrating away from areas where climate change impacts represent an increasing threat. These rapidly emerging new climate vulnerabilities in the Asia and Pacific region need to be addressed with a portfolio of strategies involving capacity building, preparedness programs, urban and rural planning, national and social security schemes, proactive migration and numerous others. Crucial preconditions for success are whole-systems and long-term thinking and planning, based on the best available data, analysis, and modeling.
This report aims to inform developing member countries of the most recent regional climate change projections and to assess the consequences of these changes for human systems. It also highlights gaps in the existing knowledge pertaining to the impacts of climate change, and identifies avenues where research continues to be needed. The information and insights presented in this report will contribute to scaling up the efforts of the Asian Development Bank (ADB) in building climate resilience in its developing member countries in the years and decades to come.
This report is the outcome of a collaboration of ADB with the Potsdam Institute for Climate Impact Research (PIK). PIK was founded in 1992. With its team of researchers in the fields of natural and social sciences, PIK generates fundamental knowledge for sustainable development primarily through data analysis and computer simulations of the dynamic processes in the earth system, and through the study of social dynamics. PIK plays an active role in the international research community such as in the Intergovernmental Panel on Climate Change, and has initiated the Nobel Laureate
Symposium on questions of global sustainability.
Since the early 1990s, ADB has provided support and assistance to countries of the region in coping with the adverse impacts of climate change. The nature and extent of this support and assistance have considerably evolved and are now multifaceted. With the recent adoption of its Climate Change Operational Framework 2017-2030 , and its commitment to achieve $2 billion in adaptation financing by 2020, ADB has asserted its strong commitment to support developing member countries to achieve climate resilient development outcomes. This initiative further underscores ADB’s commitment to provide appropriate and relevant knowledge to its developing member countries enabling them to design responses to the emerging challenges from climate change. The report also highlights the premium ADB places on its partnerships with knowledge institutions such as this joint work with PIK.
Bambang Susantono – Vice-President for Knowledge Management and Sustainable Development, Asian Development Bank
Professor Hans Joachim Schellnhuber CBE – Director, Potsdam Institute for Climate Impact Research, Professor for Theoretical Physics, University of Potsdam, Chair, German Advisory Council on Global Change
T he Asia and Pacific region is extremely vulnerable to the impacts of climate change. Unabated warming could significantly undo previous achievements of economic development and improvements of living standards. At the same time, the region has both the economic capacity and weight of influence to change the present fossil-fuel based development pathway and curb global emissions. This report sheds light on the regional implications of the latest projections of changes in climate conditions over Asia and the Pacific. The assessment concludes that, even under the Paris consensus scenario in which global warming is limited to 1.5˚C to 2˚C above preindustrial levels, some of the land area, ecosystems, and socioeconomic sectors will be significantly affected by climate change impacts, to which policy makers and the investment community need to adapt to. However, under a Business-As-Usual (BAU) scenario, which will cause a global mean temperature rise of over 4˚C by the end of this century, the possibilities for adaptation are drastically reduced. Among others, climate change impacts such as the deterioration of the Asian “water towers”, prolonged heat waves, coastal sea-level rise and changes in rainfall patterns could disrupt ecosystem services and lead to severe effects on livelihoods which in turn would affect human health, migration dynamics and the potential for conflicts. This assessment also underlines that, for many areas vital to the region’s economy, research on the effects of climate change is still lacking.
With unabated climate change, mean summer temperatures are expected to increase by more than 6˚C above preindustrial levels by the end of the 21st century over some parts of the land of Asia. Locally, temperature changes can deviate significantly from mean changes in the global or regional temperature. Climate model projections indicate stronger summertime warming over higher latitudes in Asia where the temperature increase may reach up to 8˚C.
The occurrence of heat extremes is more heterogeneously spread over the land mass of the region. Under the BAU scenario, summer temperatures considered unusual under current climate conditions might become the new norm from 2070 onward. Some areas, particularly in Southeast Asia, could enter into entirely new climate regimes due to frequent occurrence of unprecedented heat extremes.
Limiting global warming to 2˚C would significantly lower the risk of severe heat extremes. Moreover, keeping global warming below 1.5˚C would halve the percentage of Asian land areas expected to experience heat extremes compared to a 2˚C warmer world.
Climate models project a general upward trend in annual mean precipitation over most of the land of the region toward the end of the 21st century. However, the magnitude of change is much larger for the BAU scenario than for the Paris consensus scenario. Both observations and state-of-the-art climate model projections show a pronounced increase in the frequency and intensity of heavy rainfall events, particularly over Southeast Asia, which may thus face more severe flooding if the global temperature continues to rise.
If the Paris Agreement is fully implemented, sea-level rise may be limited to 0.65 meters within the course of this century. Under the BAU scenario however, sea level may rise by 1.4 meters. Under both scenarios, sea level will continue to rise for many centuries to come. For every degree of global warming, the world is committed to an eventual sea-level rise in excess of 2.3 meters. Thus, even if the 2˚C guardrail were to be respected, sea level would eventually rise by more than 5 meters over centuries and millennia.
Glaciers and Rivers
The glaciers across the High Mountain regions of Asia have shown measurable signs of recession. However, changes are highly heterogeneous. Available climate change impact assessments have shown an increase of both the risk of flooding and water shortages, as the natural storage capacities of glaciers diminish while glacial lake outburst floods become more likely. As a result, the dependency on rainwater increases. While flooding risks will increase in the Asian monsoon region due to heavy precipitation and runoff, it is also very likely that the region will face water shortages due not only to projected changes in climate but also to growing water demand from rapid population and economic growth. Options to cope with water scarcity may include integrated river basin management, adaptive management of old reservoirs, construction of new reservoirs, and techniques for efficient water use such as rainwater harvesting and water reuse.
Tropical cyclone activity by itself is driven by large internal variability that potentially prohibits the attribution of projected losses to different levels of global warming. Therefore, a quantification of the effect different degrees of global warming could have on tropical cyclone impacts for the Asia and Pacific region remains challenging. Nevertheless, there is a projected upward trend in damages under a warming climate. However, due to increasing tropical cyclone strength with rising global mean temperature and taking into account the cohazard of sea level rise, it is likely that a BAU climate development will lead to significantly higher losses than those under the climate associated with the Paris consensus climate scenario.
Climate change poses large, but regionally differing, threats to agriculture and food security in Asia through higher temperatures, drier conditions, sea-level rise, and flooding. Major uncertainties pertaining to the extent of the threat relate to the potential effects of carbon dioxide fertilization. Both biophysical climate impacts and ensuing impacts on development are likely to be substantial in the region. Currently, declining soil productivity, groundwater depletion, and declining water availability, as well as increased pest incidence and salinity, threaten food security in the region. Vietnamese paddy field by Siamak Djamei
Fisheries and Reef Ecosystems
Under the BAU scenario, all coral reef systems are projected to collapse due to mass bleaching. Recent analyses show that even with global warming limited to 2˚C, almost all coral reefs are projected to experience severe bleaching, resulting in massive dieback. This would have severe consequences for coastal livelihoods such as fisheries and tourism, as fish stocks could be greatly reduced with impaired reef ecosystems. Limiting global warming to 1.5˚C could prevent the complete loss of corals.
Energy resources, natural resources and poverty are significant variables in the generation of conflicts. Their vulnerability to climate change impacts is likely to be a future driver of instabilities. The threat of energy insecurity emerges from potential grid infrastructure failure, a continued reliance on unsustainable fossil fuels and energy imports, intermittent performance of hydropower plants as a result of uncertain water discharges, and reduced capacities of thermal power plants as a result of an increasing scarcity of cooling water. Investments in fossil fuel production like coal-fired power plants could turn into stranded assets as renewable energy sources achieve market dominance. As energy demand in the Asian region rises, yet supply becomes insecure, conflicts are a potential outcome. All these factors considered, climate change poses significant challenges to human security in Asia in the coming decades. Policy makers and investors have the chance to step in and manage risk factors by creating spaces for regional to local mitigation and adaptation strategies in order to prevent potential escalation of conflicts.
Rising temperatures, reductions in water availability, as well as an increasing frequency and severity of disaster events are already causing human displacement—a trend that could be aggravated by future climate impacts. The depreciation and degradation of natural resources through climate change threatens to lead to an increase in rural poverty and migration to cities, which will in turn add to the growth of informal settlements. Cities, as a result, will be vulnerable to both global climate events, due to their reliance on global supply chains, and local disasters, due to the vulnerability of the makeshift settlements that migrants often inhabit in urban slums. While a 2˚C temperature rise will already lead to moderate risks in some regions, a 4˚C increase could trigger severe disruptions of ecosystem services vital to the Asian economy. This could lead to humanitarian disasters in many nations and result in unmanageable migration surges, or locked-in populations.
The challenges confronting the fast-growing Asian cities with regard to climate change are twofold: (i) many of them will be affected by the consequences of global warming, and (ii) they are part of the problem, as they emit a disproportionate amount of greenhouse gases largely due to the concentration of human activities in urban areas. Already today, the number of hot days in cities is twice as high as in the hinterland. By the end of the 21st century, this number could be 10 times higher.
Disruption in supply chains caused by extreme weather events can propagate through the globalized trade network. Since Asia’s industries are particularly highly interlinked, extreme events in Asia can have strong repercussions within the region as well as in the rest of the world. Conversely, Asia’s production and consumption can suffer from events outside the region. Tailored adaptation plans need to be developed by both private and public sectors to enhance the resilience to such shock cascades. These plans also necessitate cooperation among many countries in Asia. Further research on adaptation measures to be taken by different stakeholders is critically important to support such collective action.
Climate change poses a significant risk to human health in Asia and the Pacific, threatening to reverse many of the health improvements that have been achieved in the past decades. The World Health Organization recently estimated approximately 16,000 annual deaths among children below 15 years of age related to, and 26,000 annual deaths in small children below 5 years of age related to undernutrition (stunting), attributable to climate change in the 2030s across the Asia and Pacific region. These estimates would be 8,000 for diarrheal diseases and 21,000 for undernutrition (stunting), respectively, in the 2050s. According to the same assessment, regional heat-related deaths among the elderly (over 65 years) are thought to increase by approximately 20,000 cases due to climate change by the 2030s and approximately 52,000 cases by the 2050s. Attributable mortality related to vector-borne diseases (malaria and dengue) are estimated to be on the order of 3,000 annual deaths in the 2030s and 10,000 annual deaths in the 2050s. Yet, these estimates only represent a small portion of the climate impacts on human health to be expected because many known climate-sensitive health outcomes have so far been omitted from existing analysis.
The findings of this report highlight the severity of consequences of unabated climate change in Asia. While the climate impacts under the Paris consensus scenario of a temperature increase between 1.5˚C and 2˚C will pose significant challenges to the region, it is clear that the BAU scenario would render efforts to adapt Asia’s population and economy to this new climatic regime ineffective. Because the coming decade is crucial for implementing adequate mitigation measures to deliver on the Paris Agreement, investments leading to a rapid decarbonization of the Asian economy have to receive high priority. At the same time, adaptation measures to protect the most vulnerable populations of the region need to be implemented. While pilot projects of renewable energy and technological innovation in urban infrastructure and transport need to spearhead this transformation, the consideration of mitigation and adaptation has to be mainstreamed into macro-level regional development strategies and micro-level project planning in all sectors. This would not only contribute to managing climate change risks for Asia and the Pacific, but also provide opportunities for directing regional economies toward a low-carbon and climate-resilient pathway.