The Mekong River’s vast basin ecosystem snakes from the Tibetan plateau through Myanmar into the Lower Mekong Basin in Laos and Thailand. It filters into the Mekong Delta in the southern tip of Cambodia and Vietnam, finally emptying out into the South China Sea. Along the way, it supports 80 percent of communities living in it – an estimated 60 million people.
But flooding, increased frequency and severity of disease and dry spells triggered by global temperature rises are all expected to spark downward spirals in crop yields, fish harvests and availability of non-timber forest products, according to a recent study by USAID.
Inspired by a CIAT study which described how current coffee growing regions in South America may disappear due to weather changes while new regions appear, USAID launched the Mekong ARCC Climate Change Impact and Adaptation Study.
“CIAT’s maps showing the change in viable coffee growing areas in Nicaragua quickly silenced many,” said Brad Philips, USAID’s Asia-Pacific regional climate change adaptation advisor who was busy developing programs in Southeast Asia to assist communities in adapting to climate impacts in the Mekong River Basin.
“Rural development strategies – making market chains work for the poor, strengthening the role of women in the rural marketplace, access to rural finance, risk insurance – have little value if the crops the farmers are growing have evolving comparative and competitive advantage,” he noted.
“During my career I saw how niche, high-value crops in northern Thailand helped move communities away from slash and burn opium to settled communities. What will happen as those niche crops, dependent on the highlands climates, become less viable?” wondered Philips.
Creating a new Framework
Similar thoughts had led Peter Läderach and co-author of CIAT’s report to investigate on-the-ground impacts of climate change. “Usually global climate models are not used in combination with local adaptation strategies,” said Läderach.
“We took global models in combination with crop suitability models and really drilled down to community level, carrying out surveys to show how farmers in their fields will be vulnerable to the impacts of climate change in specific locations. We wanted to show how the global models can inform local adaptation strategies on the ground.”
Inspired by this approach, the USAID Mekong ARCC study highlights more extreme weather events in the Mekong Basin – wetter wet seasons, drier dry seasons, higher temperatures; more frequent and extreme flooding. These changes will put pressure on natural systems in the basin, making land once thought ideal for certain crops unsuitable – ultimately shifting ecosystems upland.
“The assumption is that communities understand weather trends. But these are related to the past,” said Paul Hartman, director of the Mekong ARCC. “We are working with 2030, 2050 projections to help farmers see not only what could be helpful tomorrow, but to link this to what is projected to happen in years’ time.
“The central objective of the Mekong ARCC project is to serve as a nexus between the science of climate projections and on-the-ground community-led responses to the changing climate,” added Hartman.
The five-year study sought to understand the potential magnitude of climate impacts in the delta and critically, to translate them to local communities and policy makers to aid investment in adaptation measures.
What’s the bottom line?
A parallel assessment of the current day ‘values at risk’ analyzed the impacts on key livelihood sectors in the basin, described in the Mekong ARCC study. It estimates the annual value of infrastructure services, worker productivity, agricultural output, hydroelectric generating capacity, and ecosystem services at risk from climate change in the basin to be at least $16 billion a year.
In addition, the value of infrastructure assets at risk in areas expected to be inundated more frequently or permanently is around $18 billion – a total risk of about $34 billion every year.
“Our findings should resonate with policy makers in real dollars and cents – not just two or three degree increases in temperature but real economic risks that policy makers can use to understand the trade-offs,” said Hartman.
The International Bank for Reconstruction and Development has determined total annual costs of adaptation for all economic sectors in the East Asia and Pacific region to be up to $20 billion – roughly $0.56 per person. By contrast, the estimated annual $16 billion value at risk alone in the Mekong River Basin is roughly $267 per person. That’s a massive trade-off.
The bottom line then, is that even if actual climate change costs over the next few decades turn out to be a fraction of the values at risk identified in the study, adaptation expenditures would still be well worth the investment.
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Photo credit: Georgina Smith / CIAT