introduce positive benefits for rice crops in some areas in ESAP, especially in Northeast China (Wang et al., 2005).

4.2.8.2  Floods Flooding occurs annually in many parts of ESAP with posi­tive and negative impacts. Bangladesh is one of the most highly flood vulnerable countries in the world: 21% of the land area is flooded annually. India is also highly vulnerable to flooding: 40 million ha (12% of land) is flood prone. Recent episodes of flooding in Indonesia, Malaysia and Viet Nam demonstrate the vulnerability of these countries.
     Future climate change will likely alter flood patterns in the ESAP region. Projected increases in precipitation in eastern India and Bangladesh may trigger more flood epi­sodes. With a 2°C rise in global mean temperature, the mean flooded area in Bangladesh could increase by 23 to 29% (Mirza, 2005). The maximum monthly flow of the Mekong is estimated to increase by 35-41% in the basin and by 16-19% in the delta with lower values estimated for the years 2010-2038 and higher values for years 2070-2099 com­pared to 1961-90 levels. The thawing volume and speed of snow cover in spring is projected to accelerate in Northwest China and the western part of Mongolia while the thawing time could advance, increasing water sources and poten­tially leading to floods in spring (IPCC, 2007).
     Damage to crops by flooding is highly dependent on three related  factors:  timing,  magnitude  and  frequency. For example in Bangladesh, the crop calendar has evolved around the onset and retreat of the monsoon. If floods (flash floods) occur earlier than expected they can cause substan­tial damage to standing crops. However, if floods occur very late, farmers cannot replant as the growing period would be severely limited by the onset of winter.
     In Asia, climate change may negatively affect the fisher­ies sector (IPCC, 2007). Rising air temperature would lower availability of oxygen for fish species at higher elevations. In the plains, the timing and amount of precipitation could also affect the migration of fish species from river to floodplain for spawning, dispersal, and growth (FAO, 2003). Future changes in ocean currents, sea level, sea water temperature, salinity, wind speed and direction, strength of upwelling, the mixing layer thickness and predator response to climate change have the potential to substantially alter fish breeding habitats and food supply for fish and ultimately the abun­dance of fish populations in Asian waters (IPCC, 2007).

4.2.8.3  Droughts
Droughts are very common in many countries in the ESAP region. India is one of the most vulnerable countries to drought, particularly the states of Gujarat, Haryana, Raj-asthan and Punjab. Bangladesh is also highly vulnerable to drought, especially those occurring in the monsoon period, which severely affect rice crop production. In China, the ar­eas affected by drought have exceeded 6.7 million ha since 2000 in Beijing, Hebei Province, Shanxi Province, inner Mongolia and North China (Zhou, 2003; Yoshino, 2000). North Korea and Australia are also vulnerable to drought.
     Climate change could influence variations in tempera­ture, precipitation and evapotranspiration and exacerbate water shortages and drought frequency in the ESAP region (IPCC, 2007). Since over 80% of water supplies in the re-

gion are used for agriculture, crop productivity will be se­verely affected if access to water is diminished (García et al., 2006). Decreased precipitation and increases in evapotrans­piration can lead to deficiencies in soil moisture as well as stream flows that provide for irrigation (Wang, 2005). The retreat of glaciers and decline in snow melt in much of South Asia could place significant pressure on water availability in the dry summer months and instigate the gradual trans­formation of already water stricken areas into arid deserts (IPCC, 2007; Barnett et al., 2005).

4.2.8.4  Pest attack and diseases
The predicted warming trends linked to climate change are expected to influence pest and disease frequency and dam­age extent. For example, a decline in frost events in New Zealand has led to an increase in the tropical grass web-worm and caused severe damage in northern agricultural re­gions of the country (IPCC, 2007; UNEP, 2006). Changing pest and disease patterns due to climate change will likely affect how food production systems perform in the future. This will have a direct influence on food security and pov­erty levels, particularly in countries with a high dependency on agriculture (IPCC, 2007).

4.2.8.5 Adaptation The agricultural sector could minimize damage and take ad­vantage of changing environments by implementing adapta­tion measures and coping mechanisms such as the develop­ment and introduction of high temperature tolerant crop varieties (Agarwal et al., 2003). Currently available crop varieties are not capable of tolerating high temperatures, es­pecially increased nighttime temperatures. Yield responses from current rice varieties are high in response to increases in nighttime temperature (Peng et al., 2004). The develop­ment of salt tolerant crop varieties could reduce shortfalls of crops under sea level rise scenarios. Current rice varieties and especially the HYVs have two major limitations: their stems are short in length and they cannot sustain long in­undation periods during flooding resulting in severe losses of crops. In the Philippines a gene has been identified that enables rice to survive complete submergence. The develop­ment could benefit millions of farmers whose rice crops are constantly vulnerable to flooding especially in the low lying mega-deltas of ESAP.
     As water resources availability will be highly variable over time and space, technological development and diffu­sion are necessary for water conservation and increasing ir­rigation water application efficiency (roughly 40% in India and in Bangladesh). The introduction of low cost drip ir­rigation can increase efficiency; the water saved could be used to bring additional lands under irrigation. Weather information, such as advance warning on floods, droughts, pest attacks, etc., can help farmers to better prepare for extremes.
     Climate change can introduce new pathogens and ex­pand the territory of animal diseases. Improved understand­ing is needed of the mechanisms that spread pathogens, their hosts and the potential damage to animal health. Some ad­aptation measures (IPCC, 2007) for the agriculture sector in Asia will require substantial inputs of technical, financial and human resources (Table 4-5).