The Fourth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC) Working Group showed that from 1850 to 2005, the average global temperature increased by about 0.76 degrees Celsius, and global mean sea level rose by 12 to 22 centimeters over the last century1. This authoritative report concluded that the “warming of the climate system is unequivocal, as is now evident from observations of increases in global average air and ocean temperatures, widespread melting of snow and ice, and rising global average sea level.”
Consequently, the future resilience of ecosystems will not be spared by climate change. The IPCC report cited that the resilience of many ecosystems is likely to be exceeded this century by an unprecedented combination of climate change; associated disturbances (e.g., flooding, drought, wildfire, insect infestations, and ocean acidification); and other drivers of global change such as land use change, pollution, and the over-exploitation of resources2.
There is ample evidence that climate change affects biodiversity. The Millennium Ecosystem Assessment reports that climate change is likely to become the dominant direct driver of biodiversity loss by the end of the century3. As it is, climate change already forces biodiversity to adapt either by shifting habitat or by modifying life cycles.
The IPCC report predicts that in Asia up to 50 per cent of biodiversity is at risk, and as much as 88 per cent of coral reefs may be lost in the next 30 years as a result of climate change. Globally, about 20 to 30 per cent of species will be at an increasingly high risk of extinction – possibly succumbing by year 2100, as global mean temperatures exceed two to three degrees Celsius above pre-industrial levels4.
The implications of climate change for the ASEAN region’s biodiversity resources are projected to be serious. Climate change will exacerbate the many factors that are already endangering biodiversity in Southeast Asia. These stressors will be magnified over time. Much uncertainty remains over the magnitude of climate change in the ASEAN region, and how this will affect biodiversity resources.
It is Southeast Asia’s less developed nations who are most vulnerable to climate change, as its impact is expected to further worsen poverty, particularly the earning capacity of the poor, and exacerbate the already inadequate provisions for health and livelihood5.
A significant number of the region’s population remains underprivileged, subsisting mainly on the uninterrupted use of biodiversity resources, the losses of which are scaling up and proceeding largely unabated. These challenges buttress one another: climate change exacerbates poverty and accelerates biodiversity loss; poverty sequentially compels the poor to exploit the environment unsustainably. Degraded environments, in return, intensify poverty and hasten climate change. The bottom line is that if deforestation in the region continues at its current rate, Southeast Asia stands to lose up to three-quarters of its forests and up to 42 per cent of its biodiversity by 21006.
Impact on Species. Climate change is expected to impact species by affecting their populations, distributions and habitats. While habitat loss and fragmentation have been the primary drivers of past and predicted species extinctions, climate change is now putting additional pressure on many animals and plants. The risk of extinction is increasing for species that are already vulnerable, particularly those with strict habitat requirements and restricted ranges7.
Some examples of the impact on species of climate change in Southeast Asia are the following:
Impact on Coastal and Marine Resources. The Asian Development Bank (ADB) cites that climate change will affect coastal and marine resources by: 1) inundating low-lying areas, such as the delta of Cambodia and Viet Nam and certain parts of Bangkok in Thailand, through rising sea levels; 2) affecting seagrass beds in shallow tidal and sub-tidal coastal marine environments along the ASEAN region’s coastline, affecting entire food chains that thrive in seagrass ecosystems, including the “dugong” and several species of turtle and fish that feed on seagrass itself; and 3) amplifying the scale of coral bleaching and degeneration of coral reefs10.
In tropical temperate nearshore habitats, climate change causes a shift in species ranges and tolerance. Coral bleaching occurs, caused by high water temperatures that stress corals, leading them to expel the colorful symbiotic algae that corals need for survival, growth and reproduction. Increases in temperature over a long period of time will eventually kill corals, thereby diminishing ecosystem function and service. Fish population is affected by this occurrence, as the degradation of coastal habitats reduces its capacity to sustain fisheries. Poverty increases and food security diminishes as fish stocks are depleted. This drives fishers to use more and more destructive methods to catch what meager supply is left.
The ASEAN Centre for Biodiversity and the Haribon Foundation in the Philippines conducted a study in 2009 on the impacts of climate change on biodiversity in Southeast Asia. Initial findings show that avian response to climate change causes species distributions to shift pole-wards and up-slopes if current and projected ranges do not overlap, and if the species are unable to migrate. Interactions between climate change and landscape changes will impede range shifts, resulting in range contractions and potential extinctions11. In general, though research on the ecological impact of climate change on amphibians and reptiles is still in the early stages, a few studies have already linked climate change directly to ongoing population declines and species extinctions in herpetofauna.
The direct and indirect impacts of climate change to marine mammals are expected. Direct impacts include temperature and species range alterations; effects on foraging and reproduction due to sea level rise, change in species range and high juvenile mortality; massive die-offs; and shifts in distribution due to the El Niño. Indirect impacts include shifts in the distribution and productivity of prey species due to changes in temperature range, and because nursery grounds for many fish and invertebrate species that are prey to marine mammals will be affected by changes in storm frequency and intensity.
In the fisheries sector, climate change will likely force critical species of fish to migrate towards the poles, gravely disrupting fisheries and the overall marine ecosystem. Warmer water will lead to the large-scale redistribution of these species, mostly moving towards the poles – shifting by more than 40 kilometers per decade, on average.
Impact on Forests. The effects of climate change on forests are manifested through the increased occurrence of forest fires during the dry season; the rising number of pest- and disease-infestations in forest areas; the marginalized survival of seedlings consequent to changes in precipitation patterns; an upsurge in the population of invasive alien species; and intensifying soil erosion due to intermittent drought and flooding12.
Researchers studying forest fires in Indonesia say that the destruction of forests and peatlands in the country is making it more prone to forest fires, especially during the dry El Niño years. Moreover, according to Dr. Robert Field of the University of Toronto, there was a significant increase in the intensity and scale of fires since the early 1990s, owing to industrial logging and the rapid expansion of oil palm plantations. Dr. Field’s team found that Sumatra has suffered from massive forest fires since the 1960s. In Indonesian Borneo, however, where the industrial conversion of forests started later, forest fires became an occurrence beginning only in 1982, and triggered mainly by the drought years13.
In Viet Nam, the Forestry Management and Protection Division of the Ministry of Agriculture and Rural Development (MARD) recorded 226 fires in the first six months of 2009. During this period, a total forest area of 1,200 hectares was destroyed. According to MARD, slash-and-burn agriculture is one of the major causes of forest fires in the country. The occurrence of fires, however, also rose during periods when temperature readings reached over 40 degrees Celsius14.
Impact on Agriculture. Agriculture is one of the most vulnerable industries to the projected impacts of climate change15. Climate change reduces crop yields and intensifies livestock mortality consequent to heat stress and droughts; increases the loss of arable lands due to rising sea levels; and escalates the outbreak of pests and diseases16.
The ADB reported that extreme weather events have accounted for economic damage to agricultural production in Indonesia, the Philippines, Singapore, Thailand and Viet Nam17.
In 2004, a group of scientists studied the projected impacts of global warming on crop yields. They examined temperature trends and the relationship between temperature and rice yield at the International Rice Research Institute from 1979 to 2003, and found that grain yield declined by ten per cent for every 1 degree Celsius increase in growing-season minimum temperature during the dry season18.
Southeast Asia’s status as a major producer of grain and various industrial crops is threatened by drought, heat stress and typhoons – factors that are all offshoots of climate change. A significant decline in fish production due to changes in sea levels, salinity and sea temperature has also been predicted. All told, such downtrends in production are likely to aggravate the existing food insecurity in the region19.
Impact on Human Health. According to the World Health Organization (WHO), climate change is affecting the following fundamental requirements for health: sufficient food, clean air and safe drinking water. A recent assessment concluded that the global warming that has begun since the 1970s was accountable for over 140,000 excess deaths annually by year 200420.
Epidemics of dengue, malaria and other vector-borne diseases are the principal health impacts of climate change21. Dengue cases are likely to be amplified by temperature elevations and variability in precipitation22. The consequent alterations in the environment create favorable breeding conditions for mosquitoes, allowing them to multiply unabated23.
In the Philippines, cases of dengue significantly increased from an average of 5,000 cases a year in the early 1990s, to 35,500 cases in 2003. Increasing numbers were similarly observed in Indonesia, Thailand and Viet Nam24.
Cases of diarrhea-related illnesses are expected to increase consequent to the escalating frequency of drought and floods25 . Rising sea levels will promote the proliferation of water-borne infectious diseases.
The poor communities are the ones expected to bear the brunt of the impacts of climate change on health, due to their already compromised health prospects26.
1Intergovernmental Panel on Climate Change. 2007. Climate Change 2007: Synthesis Report. Available online at http://www.ipcc.ch/pdf/assessment-report/ar4/syr/ar4_syr.pdf.
3World Resources Institute 2005. Millennium Ecosystem Assessment: Ecosystems and Human Well-being: Biodiversity Synthesis. Washington, D.C. 2005.
4Intergovernmental Panel on Climate Change. 2007. op. cit.
5Asian Development Bank. 2009. The Economics of Climate Change in Southeast Asia: A Regional Review. Available online at http://www.adb.org/Documents/Books/Economics-
6Sodhi, N.S., Koh, L.P., Brook, B.W. and Ng, P.K.L. (2004). Southeast Asian Biodiversity: An Impending Disaster. TRENDS in Ecology and Evolution, Vol. 19 No. 12. 12 December 2004
7Nozawa, Cristi Marie C. 2009. Climate Change and Biodiversity: Potential Impacts on Species, Sites, Habitat and People. ASEAN Conference on Biodiversity.
8“New WCS Report Identifies ‘Unsung’ Species Under Stress from Climate Change,” Accessed on 12 March 2010 at http://www.wcs.org/press/press-releases/wcs-report-identifies-
10Asian Development Bank. 2009. op. cit.
11Haribon Foundation. December 2009. Report of the Experts’ Meeting on Climate Change, Biodiversity and Human Population in Island Ecosystems: Proposed Methods and Joint
12Asian Development Bank. 2009. op. cit.
13Butler, Rhett A. 2009. New Fire Record for Borneo, Sumatra Shows Dramatic Increase in Rainforest Destruction. Mongabay. 22 February 2009. Accessed on 17 August 2010 at
14Viet Nam Ministry of Natural Resources and Environment. 2009. Urgent action needed to tackle forest files. Accessed on 17 August 2010 at
15Zhai, F. and J. Zhuang. 2009. Agricultural Impact of Climate Change: A General Equilibrium Analysis with Special Reference to Southeast Asia. ADBI Working Paper 131, Tokyo:
Asian Development Bank Institute. Accessed on 17 August 2010 at http://www.adbi.org/working-paper/2009/02/23/2887.agricultural.impact.climate.change/
16Asian Development Bank. 2009. op. cit.
18Peng, S.B., J.L. Huang, J.E. Sheely, R.C. Laza, R.M. Visperas, X.H. Zhong, G.S. Centeno, G.S. Khush, and K.G. Kassman. 2004. Rice Yields Decline with Higher Night Temperature
from Global Warming. Proceedings of the National Academy of Scientists 101:9971-75. Accessed on 17 August 2010 at http://www.ncbi.nlm.nih.gov/pmc/articles/PMC454199/ 19Asian Development Bank. 2009. op. cit.
20World Health Organization. 2010. Climate Change and Health. Accessed on 17 August 2010 at http://www.who.int/mediacentre/factsheets/fs266/en/
21United Nations Framework Convention on Climate Change. 2007. Climate Change: Impacts, Vulnerabilities and Adaptation in Developing Countries. Accessed on 17 August 2010
22Asian Development Bank. 2009. op. cit.
23Kochtcheeva, L. and A. Singh. 2000. An Assessment of Risks and Threats to Human Health Associated With the Degradation of Ecosystems. United Nations Environment
Programme. Accessed on 17 August 2010 at http://na.unep.net/publications/heireport.pdf
24Asian Development Bank. 2009. op. cit.
25United Nations Framework Convention on Climate Change. 2007. Climate Change: Impacts, Vulnerabilities and Adaptation in Developing Countries. Accessed on 17 August 2010 at http://unfccc.int/resource/docs/publications/impacts.pdf
26World Health Organization. 2009. op. cit.
ASEAN Centre for Biodiversity. 2010. ASEAN Biodiversity Outlook: Drivers of Biodiversity Loss, pp83-87. Los Banos Laguna, Philippines 2010.