Vast areas of Southeast Asia will be frequently and irreversibly flooded before the end of the century if action is not taken to stop the destruction of tropical peatlands, a new study indicates.
The resultant loss of agricultural production will have severe socio-economic consequences, says the non-governmental organisation Wetlands International, which is based in the Netherlands. “Radical changes to land use policies on peatlands in the region are needed in order to avoid this.”
Tropical peatlands have a critical environmental function; they store about a third of the world’s terrestrial carbon reserves. In Southeast Asia, peat forests are also home to endangered species like the orangutan.
Wetlands International has called on governments and businesses to stop the conversion of peat forests to agricultural or other use immediately, and to promote peatland conservation and restoration.
The new study, which was commissioned by Wetlands International and carried out by the Deltares research institute, also based in the Netherlands, suggests that extensive drainage of peatlands for oil palm cultivation in the Rajang river delta in Sarawak – a Malaysian state on the island of Borneo – results in such massive land subsidence that this will lead to extensive and devastating flooding in the coming decades.
Deltares analysed 850,000 hectares of coastal peatland in Sarawak. The model it produced demonstrates that, in 25 years’ time, 42 percent of the area will experience flooding problems.
In 50 years’ time, the percentage affected will increase to 56 percent and the flooding will become more serious and permanent.
In 100 years’ time, about 82 percent of the Rajang Delta will be irreversibly flooded, the report states.
“The results of the model clearly show the need for a radical change in peatland land use, not only in Sarawak, but in all peat landscapes in the region”, said Lee Shin Shin, a senior technical officer with Wetlands International Malaysia.
“Current trends, whereby vast areas of peatlands are opened up for drainage-based activities, will render these areas unproductive and useless and this will adversely impact communities, industries, and biodiversity that rely on such areas for their very survival and existence.”
According to Deltares, less than 16 per cent of Sarawak’s natural peat forests remain. From 2000 to 2014, the cover of industrial oil palm plantations increased from 6 percent to 47 percent, while the area of swamp forest decreased from 56 percent to less than 16 percent. The remaining area is also mostly drained, meaning that the entire area is now subsiding.
“Substantial areas are already experiencing drainage problems,” Wetlands International states. “This will increasingly impact local communities, the economy, and biodiversity and will develop over time into disastrous proportions unless land use on the region’s peatlands is radically changed.”
The solution, Wetlands International says, lies in protecting remaining natural peat swamp forests and restoring degraded areas. “This can only be done through cooperation with local communities and industry and in combination with sustainable economic development.”
Peat soils are made up of 10 percent accumulated organic material (carbon) and 90 percent water. When water is drained from the peat soil, the carbon is turned into CO2 and is emitted into the atmosphere, causing climate change.
This carbon loss reduces the peat volume and thus causes the peat soil to subside. This process continues as long as drainage goes on and until the soil surface reaches sea or river levels, constraining the outflow of water and thus leading to flooding.
In tropical conditions, peat drainage causes the soil to subside at a rate of one to two metres in the first years of drainage, and three to five centimetres per year in subsequent years. This results in the subsidence of the soil by up to 1.5 metres within five years and four to five metres within 100 years.
Indonesia is also severely affected by the destruction of vital peatland for conversion to oil palm and pulp wood plantations.
“The study results are very relevant to Indonesia as well, where we observe the same patterns of peat swamp forest conversion, drainage, and expansion of oil palm and of acacia for pulp wood plantations,” said the director of Wetlands International Indonesia, Nyoman Suryadiputra. “Thousands of square kilometres in Sumatra and Kalimantan may become flooded in the same way as the Rajang Delta, affecting millions of people who depend on these areas for their livelihoods.”
One area of Indonesia that has been burned to make way for oil palms is the Tripa peat forest in northern Sumatra, which lies inside the Leuser Ecosystem – the only place on earth where tigers, elephants, rhinos, and orangutans can be found living together in the wild.
Huge swathes of the forest were burned in 2012, but a major international campaign has succeeded in getting new protection for the area. The local Aceh government has declared a new 1,455-hectare protected peat area and has blocked 18 illegal drainage canals. It is an important victory in the battle to protect the peatlands of Southeast Asia. In the burning of Tripa, peat layers 10 to 15 centimetres deep were destroyed.
“Tripa is one of only three remaining peat swamp forests on the west coast of Aceh that host the highest densities of orangutans anywhere in the world,” said the director of the Sumatran Orangutan Conservation Programme, Ian Singleton.
“Orangutan densities can reach as high as eight per square kilometre in these areas, compared to an average of around only one or two per square kilometre in dryland forests.”
Up to 100 orangutans are thought to have perished in the forest clearing and peat burning in Tripa. There were some 2,000 to 3,000 orangutans in the area in the 1990s, but only a few hundred are left today.
“Drainage dries the peat out, making it susceptible to fires and allowing its carbon content to oxidise and escape into the atmosphere,” Nyoman Suryadiputra said. “It’s exactly this kind of irresponsible destruction that we have seen throughout Tripa that has led to Indonesia being one of the largest emitters of greenhouse gases in the world.”
Indonesia is the third largest greenhouse gas emitting country, after the United States and China.
Scientists monitoring the amount of carbon accumulated in Indonesia’s peatland forests over thousands of years have predicted that millions of tons of carbon dioxide could be released into the atmosphere if the forests continue to be cleared, drained, and burned for oil palm and agricultural plantations.
“Indonesia’s peat swaps have evolved over thousands of years to create the perfect storage systems to lock away carbon dioxide that contributes to climate change,” said Sofyan Kurnianto, a scientist with the Centre for International Forestry Research (CIFOR) and the lead author of a study published this year in the journal Global Change Biology.
The new CIFOR study was the first to use the Holocene peat model to bring together existing data on vegetation types, litter decomposition rates, and water table depths found in Indonesia’s coastal and inland peatland areas to estimate the amount of carbon accumulated over 11,000-year and 5,000-year periods.
The model was then used to create a number of scenarios to predict the future impacts of forest clearing and peat burning for oil palm conversion.
The researchers found that, of the 3,300 tons of carbon per hectare stored in Indonesia’s coastal peatland areas, up to half would be released into the atmosphere over the 100 years after conversion to oil palm plantations – the equivalent of 2,800 years’ worth of accumulated carbon.
“What was surprising was just how slow the process of carbon accumulation and the development of peatland soils actually is, but when we disturb these systems through human activity, carbon dioxide is released very quickly,” said Daniel Murdiyarso, principal scientist at CIFOR and co-author of the report.
According to CIFOR, more than 100,000 hectares of peatland forests are destroyed each year for oil palm and other agricultural plantations.
Environmentalists say peatlands are not adequately protected in Indonesia. The Environment and Forestry Ministry says it will not be issuing any new permits to convert peatlands, but those companies that already have permits and have been operating in peatlands will be allowed to continue.
Indonesia’s government regulation No. 71/2014 on peatland ecosystem protection and management outlines the sanctions that can be imposed on companies that convert peatland into other uses at a depth of three meters or more.
The regulation states that peatland degradation is considered to have occurred if the ground water level exceeds 40 cm below the peat surface or sediment under the wetland has been exposed.
According to Greenpeace, more than 75 percent of fire hotspots in Indonesia occur on peatland. Thirty percent of those hotspots occur on land that is meant to be protected under the government’s moratorium on forest clearance, Greenpeace says.
In Indonesia alone, up to 60 billion metric tons of carbon is stored in peatlands, and, globally, the amount of carbon held in tropical peat is estimated to be 88.6 billion metric tons.
The burning of peatland is a main cause of the haze that annually chokes Indonesia and neighbouring countries, and causes innumerable health problems, including asthma, breathing problems, headaches, skin rashes, and lung, eye and skin problems.
There are no accurate statistics about the number of deaths caused by haze pollution, but Greenpeace says that modelling by researchers in 2012 attributed an average of 110,000 deaths a year in the Sumatran province of Riau to peat and forest fires. “These deaths are primarily associated with long-term seasonal exposure to smoke particles,” said the forest campaigner at Greenpeace Southeast Asia, Yuyun Indradi. “This increases to nearly 300,000 deaths during an El Niño year.”
The 12th Conference of Parties to the Convention on Wetlands of International Importance was held in Uruguay in June this year. The Convention on Wetlands, also known as the Ramsar Convention, is an intergovernmental treaty that provides the framework for national action and international cooperation for the conservation and wise use of wetlands and their resources.
More than 800 delegates from 160 countries attended the Uruguay gathering. They approved a new strategic plan to stem wetland loss and degradation and deal with such issues as food and water security. They pinpointed four main priorities.
- addressing the factors driving the loss and degradation of wetlands by ensuring that decision-makers in key sectors such as water, energy, mining, agriculture, tourism, and urban development appreciate the value and benefits that wetlands provide and include these benefits in their policies;
- renewing countries’ commitments to conserve and protect the Ramsar site network and its ecosystem services;
- promoting wise use of all wetlands and restoring wetlands that are important for biodiversity conservation, disaster risk reduction, livelihoods, and/or climate change mitigation and adaptation; and
- improving the implementation of the convention by mobilising resources, working through partnerships, building capacity, and raising awareness.
World’s loss of wetlands
A report by Nick C. Davidson, published in September 2014, said the world had lost between 64 and 71 percent of its wetlands since 1900 and the loss may have been as high as 87 percent since 1700.
“Losses have been larger and faster inland than for coastal natural wetlands,” Davidson said. “Although the rate of wetland loss in Europe has slowed, and in North America has remained low since the 1980s, the rate has remained high in Asia, where large-scale and rapid conversion of coastal and inland natural wetlands is continuing.”
Ninety percent of disasters are caused by water-related hazards like floods and droughts, Wetlands International points out. “Wetlands and the ecosystem services they provide are now considered critical to reduce disaster and climate risks and to build resilience to climatic extremes.”
Marcel Silvius, who is Wetlands International’s programme chief for climate-smart land use, says the measures to cope with soil subsidence in highly developed countries or places in temperate areas, such as the Netherlands, won’t work in Southeast Asia.
He explains that strategies like building dikes and pump-operated drainage systems cannot be used in Malaysia or Indonesia. “The predominantly rural economy along thousands of kilometres of coastline and rivers, combined with the intense tropical rainfall, makes it economically and practically impossible to implement such costly water management measures in the Southeast Asian region.”
Industry will need to phase out drainage-based plantations on peatlands, Silvius says, as these areas will be increasingly subject to flooding and eventually become unsuitable for any form of productive land-use.
“Effective policies should be drawn up, implemented, and enforced to conserve and ensure the wise use of peatlands.”
Wetlands International points to the many crops that can be cultivated on peatlands without drainage.
More than 200 commercial local peat forest tree species have been identified, such as Tengkawang, which yields an edible oil, and the latex-producing species Jelutung
“These can provide alternative and sustainable livelihood opportunities for local communities, but require piloting, improvement of varieties, and up-scaling for industrial plantations,” Silvius said.
Land cleared for oil palms in the Tripa peat swamp, Aceh, Indonesia. (Photo taken by Dita Alangkara in September 2012.)