The mega city of Karachi in Pakistan is at high risk from sea-level rise, prolonged cyclonic activity, and greater salt-water intrusion, it said.

The ADB report said: "Environmental harm due to sea-level rise in association with storm surge impacts will be significant in both the Bay of Bengal and the Arabian Sea, where cyclonic activity is projected to intensify. The delta areas of the Ganges-Brahmaputra, Godavari, Indus, Krishna, and Mahanadi rivers also experience cyclonic activity and these rivers are likely to flood more often with increased monsoonal activity. The hazard of coastal flooding is likely to be significantly increased in Bangladesh, in India in West Bengal and along the coast south to Chennai, and along a coastal strip from Karachi to Mumbai".

"In association with an intensification of the monsoon, river and local flooding will be increased in many areas-the Himalaya, northern Pakistan, northern India, Nepal, and Bangladesh. Landslide risk will increase in association with flood risk in steep terrain, particularly in the Himalaya. Nepal's mid hill ecological region is susceptible to landslide and erosion. Some pocket areas of the midwest to east regions of Nepal suffer from water stress."

"Several mega cities of South Asia-such as Dhaka in Bangladesh; and Kolkata, Mumbai, and Chennai in India-are at high risk of sea-level rise, prolonged cyclonic activity, and greater salt-water intrusion, which is likely to affect a large number of people due to high population density and poor urban planning. Salinity ingress due to sea-level rise is becoming a major climate episode in some parts of Bangladesh."