Climate in Asia and the Pacific

Variations in climate in the Asia-Pacific region play a major role in the development of natural ecosystems and of human societies. Furthermore, human activities place additional stresses on natural and societal systems and climate change is now considered a significant factor in these increases. The book documents the climate of the region and interactions of the climate with both the environment and societies in the region. The book emphasizes the impacts of climate change as well as strategies to mitigate and adapt to those impacts. A number of aspects of climate in the region that capture interactions between climate and natural and human systems are considered and include climate variability and change, climate and urbanization, climate and security, climate and society, and climate and sustainability.

The book draws on published results in the scientific literature and the analysis presented highlights key climate-related issues for Asia and the Pacific. Subsequent chapters of the book include important issues such as: Climate variability and change – large-scale climate systems, trends in mean climate, trends in extreme climate events across Asia and the Pacific, challenges and opportunities for modeling the climate, current projections for future climate under climate change; Society and urbanization – trends in urbanization, interactions between urban areas and climate, climate hazards and vulnerabilities for urban areas, climate change mitigation and adaptation strategies for urban areas; Food, water and energy security – meeting future needs for rice and wheat across Asia, food from fisheries, water security, and balancing energy demands with reduced GHG emissions; Governance and sustainability – institutional arrangements to address the impacts of climate change, prospects for remote communities under climate change, effects of climate change on human health, low carbon development pathways, and ecosystem services to enhance the adaptive capacity of communities.

The geographic extent of Asia and the Pacific leads to great variation in the climate of the region. Major influences on global climate arise from the scale and elevation of the Himalayan Tibetan Plateau (HTP), and from the air-sea interactions in the Pacific associated with the El Niño–Southern Oscillation (ENSO). The monsoon has a profound effect on the climate of Asia, with its strong seasonal cycle. Variability is also caused by ENSO, the Indian Ocean Dipole (IOD) and Pacific Decadal Oscillation (PDO). ENSO is the principal source of inter-annual global climate variability. ENSO has significant climate and societal impacts on both regional and global scales. The climate effects of ENSO are modulated on decadal time scales by the PDO. IOD affects the climate in the Indian Ocean and Australasia. Climate observations show significant warming trends in temperature across Asia and the Pacific; not only is there an increase in mean temperature, but there is more warming in North Asia and less in the Pacific during the twentieth century. Observed trends in precipitation are more variable, with some evidence of increasing intensity of storms. Glacier mass balance studies show dramatic decline in ice mass in the Himalayas and New Zealand, with monitored ice mass losses of 0.3–0.5 km²/year, in the last three decades. Temperature extremes have changed region wide: cool nights, cold days have very significantly decreased universally, and the frequency of hot days has increased. Projections of future climate change for the region suggest longer summer heat waves in South and East Asia and Australia, and increases in precipitation in several areas. Regional downscaling techniques are used to project future climate: warming is projected to be largest in high latitude (Northern Asia, Central Asia) and high altitude (Tibetan Plateau) regions; with a suppression of the south Asian summer monsoon, along with a delay of monsoon onset and increase of monsoon break periods. Monsoon precipitation is projected to increase over South Asia.

Urbanization is a major factor across Asia and the Pacific, and so the scope of this chapter is somewhat restricted. There is a focus on larger urban areas, as the small communities of rural areas are discussed in other chapters. The breadth of the topic of urbanization also means that reports by government agencies and NGOs (grey literature) are cited, as well as the formal academic literature. The six sections of the present Chapter systematically review literature in the field. In the first section we overview urbanization trends in the region. In the second section we review the history of urbanization in the region. The third section examines urbanization and climate in Asia and the Pacific. The fourth section describes the risks in urban areas due to climate change-related hazards. The fifth section overviews mitigation and adaptation measures in the region. The final section concludes with the needs for resilient cities and addresses uncertainties, research gaps and policy measures.

Future predictions suggest that large cities will not hold most of the region’s total urban population. In 1990, cities of larger than one million held almost 35.1 % of the total urban population and by 2025 the UN predicts that cities of one million or more will hold 41.2 % of the total urban population. The share of those living in mega-cities is expected to increase from 8.9 % of the total urban population to 12.8 % during the same period. While expectations are for an increase in share, there still remains 58.2 % of the urban population living in settlements smaller than one million. This fact is all the more impressive given the large population that is expected to move into cities in the region between 2010 and 2025 (over 549 million in 15 years, or over 36 million people a year).

Climate resilient cities are those that can withstand climate effects and not change dramatically. They include biophysical and socio-economic sub-systems that can withstand various climate impacts and continue to develop in a fairly predictable manner. Cities that are not resilient change dramatically to new states with new relationships emerging both within the socio-economic sub-system and between the socio-economic and biophysical sub-systems. Resilient cities are sustainable cities. Resilience can be achieved when urban areas move along a more sustainable pathway. The goal of policy makers and stakeholders for their individual urban centres, urban regions as well as nations in the face of climate change is to enhance resilience. In the present review of cities in the Asia-Pacific region, we identify some important aspects that impinge on this goal. Addressing uncertainties, research gaps and policy needs related to climate change and urbanization will help make cities in the region more resilient.

The impacts of increasing natural climate disasters are threatening food security in the Asia-Pacific region. Rice is Asia’s most important staple food. Climate variability and change directly impact rice production, through changes in rainfall, temperature and CO₂ concentrations. The key for sustainable rice crop is water management. Adaptation can occur through shifts of cropping to higher latitudes and can profit from river systems (via irrigation) so far not considered. New opportunities arise to produce more than one crop per year in cooler areas. Asian wheat production in 2005 represents about 43 % of the global total. Changes in agronomic practices, such as earlier plant dates and cultivar substitution will be required. Fisheries play a crucial role in providing food security with the contribution of fish to dietary animal protein being very high in the region – up to 90 % in small island developing states (SIDS). With the warming of the Pacific and Indian Oceans and increased acidification, marine ecosystems are presently under stress. Despite these trends, maintaining or enhancing food production from the sea is critical. However, future sustainability must be maintained whilst also securing biodiversity conservation. Improved fisheries management to address the existing non-climate threats remains paramount in the Indian and Pacific Oceans with sustainable management regimes being established. Climate-related impacts are expected to increase in magnitude over the coming decades, thus preliminary adaptation to climate change is valuable.

Water security has become a defining issue of the twenty-first century for Asia and the Pacific. In the case of the Himalaya-Tibetan Plateau (HTP) region, cross-border conflicts over international water rights have also led to increased geopolitical tensions. For the Pacific, the main sources of freshwater for island communities is very limited being constrained to rainwater, surface water and groundwater. There is a need for a range of effective water management strategies for dealing with water security issues ranging from more effective water governance through to enhanced community participation. Flood disasters are the most frequent and devastating and their impacts have grown in the region. For longer term disaster risk reduction planning procedures are required as integral elements for ‘good governance’ of floods.

Energy security in three major energy-consuming economies in Asia; namely China, India and Japan is crucial, and requires climate change mitigation policies. Both energy efficiency and renewable energy are important factors in solutions to the energy conundrum. Technological innovation and diffusion is an important component for improving energy efficiency, with the promotion of renewable energy requiring financial investment and innovation. However, costs of new technologies are likely to decrease as they become more widely adopted. Demand side management is also need to provide key solutions.

The complexity of climate governance at multiple levels leads to fragmented approaches and there is a mismatch between international agreements and commitments that leads to delays in progress. Climate governance requires a great amount of dialogue, action and financing, and strengthening institutional frameworks for climate governance is desirable. Developing and widely disseminating technologies and methodologies for securing food and eradicating climate-induced health risks, that especially targets poorer communities, is crucial. Empowering poorer communities in this aspect will help alleviate the problems faced by the most vulnerable. Also crucial to creating a resilient community is the implementation of adaptation measures and poverty reduction approaches, both of which need to be integrated into national development plans. Given the urgency for capacity building to improve climate responses, enhanced efforts in collaboration with national institutions and international partners, including the private sector, is needed. In the longer term, establishing international funding and technology transfer mechanisms based on a comprehensive climate agreement is desirable.

Remote communities are geographical hotspots that suffer the impacts of multiple climate hazards, lacking access to assets, and little adaptive capacity. The Chapter focuses on two very different communities of the Himalaya-Tibetan Plateau (HTP) and the Small Island Developing States (SIDS), situated in both the Pacific and Indian oceans. Capacity building and community-based adaptation is needed for these vulnerable countries. Climate hazards disrupt ecosystem services that support human health and livelihoods, and climate impacts will affect health systems and cause fatalities through various means. Climate-induced threats to food security will lead to increasing malnutrition and consequent nutrition disorders, with implications for child growth and development. Important for small and remote communities is access to information on climate change and its impacts. While awareness-raising activities are becoming more evident, there is still a great need to strengthen climate information networks that clearly outline social vulnerabilities. For this reason, more emphasis on community-based activities to strengthen their adaptive capacity is needed where all sectors are involved and where climate change is integrated and mainstreamed through national adaptation and sustainable development plans.

Projected change in climate in the coming decades adds a layer of complexity in the search for sustainability. Warming temperatures, rising sea levels, changing precipitation patterns and their impacts on natural and human systems could threaten the attainment of development goals. Many countries in Asia and the Pacific are among the most vulnerable to the impacts of climate change and there is growing recognition that climate change adaptation must be tackled as an integral part of the development process, for example in mainstreaming climate change adaptation into national plans and programmes. The aim of Chap. 6 is to explore linkages between sustainable development and efforts to address climate change in Asia and the Pacific, particularly focussing in two areas of low carbon development (LCD) pathways for the region, and the importance of natural ecosystems in sustaining the delivery of ecosystem services that are essential for climate change adaptation and mitigation. The challenges posed by climate change will be felt in the coming decades in Asia and the Pacific. In parallel, nations in the region will continue to aspire for sustainable development. Policy makers and development workers must find ways to ensure that both these concerns are addressed synergistically while avoiding negative outcomes. One way to mitigate climate change while pursuing sustainable development is through LCD, which will require negotiations across many stakeholders of governments, non-government agencies, industry and broader communities. In Asia and the Pacific natural ecosystems will continue to play a critical role in addressing climate change adaptation and mitigation. Nations in the region will have to find innovative ways to manage and rehabilitate natural ecosystems for a multiplicity of functions and services. This will involve greater collaboration and communication between scientists and policy makers as well as between natural and social scientists. In many developing countries, there is still very limited empirical information and research needs to be ramped up. North-South and South-South partnerships could help fill the gap.

There are clear trends of increasing temperature in the Asia-Pacific region. There are observed trends in extreme climate events and evidence of changes in large-scale climate systems including the monsoon and the associated Hadley circulation. Modeling the climate of the region provides opportunities for improved understanding and prediction, but there remain challenges especially for mountainous terrain and small islands. Current projections for future climate indicate that existing stresses are likely to be exacerbated.

Urbanization is expected to continue and better understanding of the interactions between climate and urban areas is essential. Further work is needed to improve our understanding of adaptation and mitigation both in urban areas and in small communities. Significant challenges exacerbated by climate variability and change need to be overcome so that future needs for rice and wheat can be met. Management strategies need to be implemented globally so that fisheries will be able to provide necessary food for the region. Local management strategies are also needed to ensure water security.

Regional and international cooperation is providing initial support for integrated assessments that can investigate pathways towards low carbon development (LCD) across the region. Natural ecosystem services support substantial components of economies across the region and new strategies are being developed to enhance the resilience of natural ecosystems impacted by climate change. Natural ecosystems in Asia and the Pacific can contribute significantly to the mitigation of climate change.

Communities, particularly poor and remote communities, are vulnerable to climate change and there is a need for capacity building in research, policy development and implementation to reduce these vulnerabilities. International cooperation exists in the development of mechanisms to promote systematic observations of geophysical variables. Further cooperation is needed to ensure that consistent high-quality socio-economic data are collected, archived and accessible. Continuous monitoring of the geophysical environment and associated socio-economic variables, and developing and analyzing indicators of climate interactions with natural ecosystems and human societies is needed to fully interpret and respond to the complex socio-economic interactions with the Earth’s climate.