Increase in mean annual, maximum and minimum temperatures by 0.14°C between 1971 to 2000

Increase in annual mean rainfall since 1980s and in number of rainy days since 1990s, increase in inter-annual variability of onset of rainfall

PAGASA, 2001; Cruz et al., 2006

10.2.4 Impacts of observed changes in climate trends, variability and extreme events

102.4.1 Agriculture and food production

Production of rice, maize and wheat in the past few decades has declined in many parts of Asia due to increasing water stress arising partly from increasing temperature, increasing frequency of El Niño and reduction in the number of rainy days (Wijeratne, 1996; Aggarwal et al., 2000; Jin et al., 2001; Fischer et al., 2002; Tao et al., 2003a; Tao et al., 2004). In a study at the International

Rice Research Institute, the yield of rice was observed to decrease by 10% for every 1°C increase in growing-season minimum temperature (Peng et al., 2004). A decline in potentially good agricultural land in East Asia and substantial increases in suitable areas and production potentials in currently cultivated land in Central Asia have also been reported (Fischer et al., 2002). Climate change could make it more difficult than it is already to step up the agricultural production to meet the growing demands in Russia (Izrael and Sirotenko, 2003) and other developing countries in Asia.

Table 10.3. Summary of observed changes in extreme events and severe climate anomalies


Key trend




Heatwaves broke past 22-year record in May 2005

Shein, 2006


Heatwave duration has increased by 8 to 18 days in last 40 years; coldwave duration has shortened by 13.3 days

Batimaetal., 2005a


Increase in frequency of short duration heatwaves in recent decade, increasing warmer days and nights in recent decades

Zhai et al., 1999; Zhai and Pan, 2003


Increasing incidences of daily maximum temperature >35°C, decrease in extremely low temperature

Kawahara and Yamazaki, 1999; Japan Meteorological Agency, 2005


Increasing frequency of extreme maximum temperatures with higher values in 1980s and 1990s; decrease in frequency of record low temperatures during 1958 to 2001

Ryoo et al., 2004


Frequency of hot days and multiple-day heatwave has increased in past century; increase in deaths due to heat stress in recent years

De and Mukhopadhyay, 1998; Lal, 2003

South-East Asia

Increase in hot days and warm nights and decrease in cold days and nights between 1961 and 1998

Manton et al., 2001; Cruz et al., 2006; Tran et al., 2005

Intense Rains and Floods


Increase in heavy rains in western Russia and decrease in Siberia; increase in number of days with more than 10 mm rain; 50 to 70% increase in surface runoff in Siberia

Gruza et al., 1999; Izrael and Anokhin, 2001; Ruosteenoja et al., 2003; Gruza and Rankova, 2004


Increasing frequency of extreme rains in western and southern parts including Changjiang river, and decrease in northern regions; more floods in Changjiang river in past decade; more frequent floods in North-East China since 1990s; more intense summer rains in East China; severe flood in 1999; seven-fold increase in frequency of floods since 1950s

Zhai et al., 1999; Ding and Pan, 2002; Zhai and Pan, 2003; Zhai, 2004


Increasing frequency of extreme rains in past 100 years attributed to frontal systems and typhoons; serious flood in 2004 due to heavy rains brought by 10 typhoons; increase in maximum rainfall during 1961 to 2000 based on records from 120 stations

Kawahara and Yamazaki, 1999; Isobe, 2002; Kajiwara et al., 2003; Kanai et al., 2004

South Asia

Serious and recurrent floods in Bangladesh, Nepal and north-east states of India during 2002, 2003 and 2004; a record 944 mm of rainfall in Mumbai, India on 26 to 27 July 2005 led to loss of over 1,000 lives with loss of more than US$250 million; floods in Surat, Barmer and in Srinagar during summer monsoon season of 2006; 17 May 2003 floods in southern province of Sri Lanka were triggered by 730 mm rain

India Meteorological Department, 2002 to 2006; Dartmouth Flood Observatory, 2003.

South-East Asia

Increased occurrence of extreme rains causing flash floods in Vietnam; landslides and floods in 1990 and 2004 in the Philippines, and floods in Cambodia in 2000

FAO/WFP, 2000; Environment News Service, 2002; FAO, 2004a; Cruz et al., 2006; Tran etal., 2005



Decreasing rain and increasing temperature by over 1 °C have caused droughts; 27 major droughts in 20th century have been reported

Golubev and Dronin, 2003; Izrael and Sirotenko, 2003


Increase in frequency and intensity of droughts in recent years; droughts in 1999 to 2002 affected 70% of grassland and killed 12 million livestock

Batima, 2003; Natsagdorj et al., 2005


Increase in area affected by drought has exceeded 6.7 Mha since 2000 in Beijing, Hebei Province, Shanxi Province, Inner Mongolia and North China; increase in dust storm affected area

Chen et al., 2001; Yoshino, 2000, 2002; Zhou, 2003

South Asia

50% of droughts associated with El Niño; consecutive droughts in 1999 and 2000 in Pakistan and N-W India led to sharp decline in watertables; consecutive droughts between 2000 and 2002 caused crop failures, mass starvation and affected ~11 million people in Orissa; droughts in N-E India during summer monsoon of 2006

Webster et al., 1998; Lal, 2003; India Meteorological Department, 2006

South-East Asia

Droughts normally associated with ENSO years in Myanmar, Laos, Philippines, Indonesia and Vietnam; droughts in 1997 to 98 caused massive crop failures and water shortages and forest fires in various parts of Philippines, Laos and Indonesia

Duong, 2000; Kelly and Adger, 2000; Glantz, 2001; PAGASA, 2001



On an average, 20 cyclones cross the Philippines Area of Responsibility with about 8 to 9 landfall each year; with an increase of 4.2 in the frequency of cyclones entering PAR during the period 1990 to 2003

PAGASA, 2001


Number and intensity of strong cyclones increased since 1950s; 21 extreme storm surges in 1950 to 2004 of which 14 occurred during 1986 to 2004

Fan and Li, 2005

South Asia

Frequency of monsoon depressions and cyclones formation in Bay of Bengal and Arabian Sea on the decline since 1970 but intensity is increasing causing severe floods in terms of damages to life and property

Lal, 2001, 2003


Number of tropical storms has two peaks, one in mid 1960s and another in early 1990s, average after 1990 and often lower than historical average

Japan Meteorological Agency, 2005

Table 10.4. Recent trends in permafrost temperatures measured at different locations (modified from Romanovsky et al., 2002 and Izrael et al., 2006)



Permafrost temperature change/trends



East Siberia (1.6 to 3.2 m), 1960 to 1992


Romanovsky et al., 2001

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