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Climate Change Will Harm Mekong Basin Harvests

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By Alex Kirby, Climate News Network

LONDON – One of the most fertile areas of south east Asia, the Lower Mekong Basin, faces a bleak future from the impacts of climate change, according to a U.S.-funded study.

The lead author of the study, Dr. Jeremy Carew-Reid, says some of its findings are “very shocking.”

Hotter and wetter rainy seasons and more long-lasting dry seasons in Cambodia, Laos, Thailand and Vietnam will jeopardize the region’s reputation as one of the world’s major producers of crops on which hundreds of millions depend. Climate change will also have a profound economic impact in the region.

The fertility of the region around the Mekong will suffer due to a changing climate.
Credit: Thomas Schoch

“We’ve found that this region is going to experience climate extremes in temperature and rainfall beyond anything that we expected”, says Dr. Carew-Reid.

The Basin is known for its production of maize and rice, the two grains with the highest worldwide production levels. Rice provides more than a fifth of the calories consumed by humans. The study forecasts fundamental shifts in the kinds of crops that can be grown in parts of the Basin.

The USAID-funded Climate Change Adaptation and Impact Study for the Lower Mekong examines how changes in temperature and precipitation will affect growing conditions and yields for major crops including not only maize and rice but rubber, cassava, soya and coffee, and  how fisheries and livestock productivity will be affected.

There’s general international agreement that global average temperatures should if possible be prevented from rising more than 2°C above their pre-industrial level, although most climate scientists believe it’s now too late to stop temperatures rising further.

A global average rise of 2°C is expected to mean that parts of the tropics like the Mekong Basin will warm by between 4°C and 6°C by mid-century. The impacts will vary, but all the Lower Mekong countries are likely to see big changes in the suitability of land for important crops.

Protein source at risk

The study expects higher temperatures and more rainfall to decrease the feasibility of growing rain-fed rice in the lowlands of Thailand’s northern Chiang Rai Province but to increase yields in the north eastern province of Sakon Nakhon.

The study expects higher temperatures and more rainfall to decrease the feasibility of growing rain-fed rice in the lowlands of Thailand’s northern Chiang Rai Province.
Credit: Mekong ARCC

More rain in Cambodia is likely to reduce cassava and rubber yields in the Kampong Thom and Mondul Kiri regions, while temperature and rainfall increases will result in coffee in Laos having to be cultivated at higher altitudes.

Hotter and wetter weather will alter the Central Highlands in Vietnam, making the area more suitable for rubber but less so for maize and coffee.

The study also identifies “hot spot” provinces in the Basin where the impact of these changes is expected to have severe effects on food security and livelihoods.

The results of the study will help with the monitoring of how and when the “comfort zones” of key crops – areas where temperature, rainfall and soil conditions create the right conditions for production – will move. The ability to continue existing crop production in these zones is expected to decline.

For fisheries and livestock the impacts of a changing climate may also be serious (fisheries are a key source of protein in the Basin). Feed typically accounts for 65-80 percent of livestock production costs, so climate impacts on crops like maize and cassava will also damage livestock farmers.

In Vietnam, heat stress may limit the farming of freshwater prawns and flash floods could cause sudden drops in salinity, with disease spreading into coastal shrimp ponds.

International impact

The impacts on agriculture will be accompanied by damage to the natural world, with more plant and animal populations and species likely to be lost to extreme temperatures and dry spells.

The study stresses that climate change is not about the environment alone. The countries of the Lower Mekong Basin are major food exporters, and a warming climate will affect every economy in the region.
Credit: Mekong ARCC

The study stresses that climate change is not about the environment alone. The countries of the Lower Mekong Basin are major food exporters, and a warming climate will affect every economy in the region.

“Adaptation to climate change does not just mean shifting from one crop to another,” says Paul Hartman, director of the Bangkok-based Mekong Adaptation and Resilience to Climate Change (Mekong ARCC) project, the body responsible for the study. “It also means being aware of potential changes, looking out for warning signs that these changes are beginning to occur, and being prepared to respond.”

In another sign of concern at the implications of climate change for south east Asia, a senior US military figure identified it earlier this month as a priority issue.

Admiral Samuel Locklear, who heads the U.S. Pacific Command, said significant upheaval related to the warming planet “is probably the most likely thing that is going to happen… that will cripple the security environment, probably more likely than the other scenarios we all often talk about.’’

The Boston Globe reported him as saying: “We have interjected into our multilateral dialogue – even with China and India – the imperative to kind of get military capabilities aligned [for] when the effects of climate change start to impact these massive populations.

“If it goes bad, you could have hundreds of thousands or millions of people displaced and then security will start to crumble pretty quickly.’’ 

Alex Kirby, a former BBC environment correspondent, is a founding journalist of Climate News Network. Climate News Network is a news service led by four veteran British environmental reporters and broadcasters. It delivers news and commentary about climate change for free to media outlets worldwide.

Comments

By Michael D Smith (Near Chicago, IL)
on March 31st, 2013

In other words, it is just another study that projects the impacts of > 2°C, without any explanation of whether such a change is probable or possible.

I’ve got news for you Alex.  The Mekong delta is in the tropics at 10°N.  The sensitivity to CO2 is zero in the tropics due to the overwhelming activity of water vapor which actively removes heat by carrying it aloft and exposing it almost directly to space, and in the process actively shades warm areas.  It is like hitting a brick wall, I don’t care if it’s 395 ppm CO2 or 3,950 ppm.  CO2 is utterly irrelevant in the tropics.  You couldn’t move it 1°C if you had to.  I’m not saying it’s all that relevant anywhere else, but at least you might have SOME hope of measuring a difference in other places.  In the tropics, the best you could hope for is changing the time of day of the onset and decay of thunderstorms and cloud cover.  You could presumably change that a minute or two, but that’s a stretch.

Good grief.  Will the junk science ever end.

Reply to this comment

By Mary the Meteoroogist (Portland, OR 97219)
on April 1st, 2013

I would be willing to bet that in 10 years, the agricultural production of the Mekong Delta will be dramatically HIGHER, not lower.  This part of the world is making rapid advances in productivity and prosperity.

This statement…

“Hotter and wetter rainy seasons and more long-lasting dry seasons in Cambodia, Laos, Thailand and Vietnam will jeopardize the region’s reputation as one of the world’s major producers of crops on which hundreds of millions depend. Climate change will also have a profound economic impact in the region.”

...Is totally speculative.  I suspect the temperature of the region hasn’t even risen half a degree yet.  Michael Smith’s comment on CO2 sensitivity in the tropics is spot on.  This “study” is fear-mongering junk science.

Reply to this comment

By Bekky Hobson (Athens, Ohio)
on April 1st, 2013

In some of my classes we have discussed how vulnerable the tropics are to climate change. Considering this is where a generous amount of peoples’ major food source is grown, it is a ever growing concerning problem. One issue that is little touched upon in the climate change realm is population growth and the need to sustain more people. Along with that goes how to feed these ever growing groups of people. Our agricultural systems across the world are facing major changes.

We are being hit harder by more intense storms and droughts. The seasons are already changing in the tropics (as mentioned above). Due to the fact that the predictions climate scientists made years ago are happening and occurring years before they thought they would, we need to find real solutions now. In my opinion, next to energy, agriculture is one of those main areas. Our food supply and growing process is being heavily threatened by global climate change, which means us. Yes, adaptation is key to these changing seasons and new climate, but there also must be mitigation as well. We need to look at our current farming practices and asses what harmful practices are only furthering the feedback loop of rising temperatures. This is especially serious in this area because the Lower Mekong Basin feeds so many people. They’ll have to continue to move their growing fields. It is important to look at the full scope of these problems.

Reply to this comment

By Michael D Smith (Near Chicago, IL)
on April 3rd, 2013

Bekky, it is time for you to ask for your money back from OU.  You are not being hit by more intense storms or droughts.  Neither is anyone else.  Nor is the cost changing.  A major hurricane has not hit the USA in over 7 years, this hasn’t happened since the civil war.  The 2012 drought was not even in the same league as the 1930’s (check the PDI).  We are, however, entering a period of cool PDO and warm AMO.  Last time that happened in the 1950’s, we had 5 majors in ONE year.  So you might see a huge uptick in hurricanes both in strength and frequency, but it will be due to cyclical cooling, not warming.

Read skeptical sites and alarmist sites.  See which ones are supported by facts and details, and which ones are propaganda.  You decide.

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