MANILA -- Increased rainfall and temperature due to climate change could bring benefits to South-East Asian agriculture, a study suggests, contradicting more common expectations that a warmer planet will reduce agricultural productivity in the region.
Scientists from the International Water Management Institute (IWMI) have predicted that precipitation levels in vast areas of South-East Asia will remain stable, and most of the anticipated changes will occur over the sea, rather than over land.
In southern Vietnam and Cambodia, for instance, precipitation changes will be so minimal that farm production will barely be affected. In central and northern Myanmar, the increase will in fact help to raise crop output, as these are the driest areas in the region.
An increase in temperature may also increase crop yield in northern parts of Thailand, Laos and Myanmar, since crops such as rice and vegetables rely on regular rainfall and are most vulnerable to variability in weather.
'At the regional scale, precipitation and temperature changes should benefit agricultural production, as significant precipitation increases will occur in the drier areas, whereas the steepest temperature rises will affect the coldest parts,' says the study.
The study was carried out by IWMI scientists Guillaume Lacombe, Chu Thai Hoanh and Vladimir Smakhtin.
Lacombe, the study’s lead author, told SciDev.Net that the findings will help the region's policymakers plan for food security — which is being threatened by climate change.
'This study helps characterise and quantify climate change,' said Lacombe. 'It could help [in sustaining] food security by showing where most drastic changes in rainfall patterns over the long term will occur. This should help the prioritisation of areas of intervention for climate change adaptation.'
Lacombe said he and fellow hydrologists drew this conclusion through using PRECIS (Providing Regional Climates for Impacts Studies), a regional climate modelling system designed to run on a Linux-based (an open source operating system) computer and to give detailed climate change projections in any region.
Despite optimistic results, Lacombe pointed out that climate change will have other impacts, such as rises in sea level, which could make the Mekong Delta in southwestern Vietnam more saline, leading to the destruction of rice farms. Climate change could also increase pest numbers and disease prevalence.
Lacombe said that policymakers in the region needed to consider climate projections obtained using several other climate models — in addition to the PRECIS model — before making any decisions about an appropriate response. He also stressed that PRECIS is a regional model and not a global model.
The study concludes with a call for further studies to focus on how climate trends might interact with other environmental changes caused by the region's demographic and economic developments.