Nov 27 2008
Unless immediate action is taken, climate change could have a devastating effect on the world's forests and the nearly 1 billion people who depend on them for their livelihoods, warned a leading group of forest scientists in a report to be released next week.
The researchers from the Center for International Forestry Research (CIFOR) called for the implementation of adaptation measures to reduce the vulnerability of forests and forest-dependent communities that will experience an unprecedented combination of climate change-associated disturbances like flooding, drought, wildfire, and other environmental challenges in the next 100 years.
Negotiations within the United Nations Framework Convention on Climate Change (UNFCCC) are set to begin to reduce tropical deforestation and forest degradation, and therefore greenhouse gas emissions. Yet according to Facing an Uncertain Future: How Forests and People can Adapt to Climate Change, a new book by CIFOR that will be released next week at the UNFCCC Conference of Parties meeting in Poland, immediate measures must be taken now to adapt forests to climate change. Measures include buffering ecosystems against climate-related disturbances and selecting species in plantations better suited to predicted changes in climates.
If they are managed properly, forests can greatly assist vulnerable communities adapt to the impacts of climate change, yet if they are not managed sustainably, forests will exacerbate these impacts. Similarly, because of their ability to take carbon dioxide out of the atmosphere, forests have the potential to be a big part of the solution to climate change. However, if forests are destroyed, the increasing amount of carbon in the atmosphere could lead to the destruction of what remains. So it is a self-perpetuating cycle, according to the report.
"The imperative to assist forests and forest communities to adapt to climate change has been poorly addressed in national policies and international negotiations. The adaptation challenge is being treated as secondary to mitigation, and yet the two are inextricably linked," said Frances Seymour, Director General of CIFOR.
Forests provide millions of people with income, food, medicines and building materials and deliver many vital ecosystem services like flood or drought regulation and water purification, according to CIFOR's report. They are, therefore, critical to the ability of human societies to adapt to climate change.
The report identifies two related but distinctive adaptation responses. One of these would aim to adapt forest management and conservation to reduce the impacts of climate change on forest ecosystems.
"We have identified two broad categories of adaptation measures for forest ecosystems," said Bruno Locatelli, a CIFOR scientist and lead author of the report. "The first is to buffer ecosystems against climate-related disturbances like improving fire management to reduce the risk of uncontrolled wildfires or the control of invasive species. In plantations, we can select species that are better suited to coping with the predicted changes in climate. The second would help forests to evolve towards new states better suited to the altered climate. In this way we evolve with the changing climate rather than resist it."
A second adaptive response is to help the people who are managing, living in or conserving forests to adapt to future changes.
"The people living in forests are highly dependent on forest goods and services and are often very vulnerable socioeconomically," said Locatelli. "They usually have a much more intimate understanding of their forests than anyone else, but the unprecedented rates of climate change will almost certainly jeopardise their ability to adapt to new conditions. They will need help."
The report reviewed the scientific literature on the effects of climate change on forests and came to several alarming conclusions:
By the end of the 21st century, tropical regions in Africa, South Asia, and Central America are likely or very likely to be warming at a faster rate than the global annual mean warming.
Rainfall in East Africa and during the summer monsoon of South and Southeast Asia is likely to increase.
Annual precipitation in most of Central America is likely to decrease; this region is the most prominent tropical hotspot of climate change. It is unclear how rainfall in the African Sahel and the Amazon will change.
Peak wind intensities of tropical cyclones are likely to increase, in particular in tropical Southeast Asia and South Asia, bringing extreme rainfall.
Droughts and floods are expected to increase globally, making water management more difficult.
"In many forests, relatively minor changes in climate can have devastating consequences, increasing their vulnerability to drought, insect attack and fire," said CIFOR forest ecologist Markku Kanninen, a co-author of the report. "Burning or dying forests emit large quantities of greenhouse gases, so there is a chance that an initially small change in climate could lead to much bigger changes."
Mountain forests might be the first to disappear, said Kanninen. "We know that cloud forests are extremely sensitive to climatic changes, as are other types of mountain forest, because when temperatures increase and rainfall decreases, they have nowhere to go." Mangrove forests in coastal parts of West Africa, which help mitigate storms and underpin many commercial fisheries, are highly vulnerable to rising sea levels, according to the report. Some mangroves are expected to dry out almost completely – droughts in Senegal and The Gambia have already had devastating effects on mangrove communities.
Scientists have already found examples of biodiversity loss due to climate change. In the highland cloud forests of Costa Rica, the lifting of the cloud base associated with increased ocean temperatures has been linked to the disappearance of 20 species of frogs.
"That is just a foretaste of what could be huge losses of forest biodiversity worldwide due to climate change,' said Kanninen. Several studies have predicted that decreased rainfall in the biodiversity-rich Amazon would cause massive dieback of the forest and its large-scale substitution by savannah.
"Tropical dry forests are also highly vulnerable," said Kanninen. "Only slight decreases in rainfall, predicted in many regions, will make them more susceptible to fire and to long-term ecological shifts that potentially could cause the extinction of thousands of species."
According to the report, adaptation policy must be multi-sectoral. For example, ministries of transportation have an interest in conserving healthy forests. Haze from forest fires in Indonesia is often thick enough to close airports, while landslides often close roads. Drinking water or hydroenergy companies in South America are starting to consider upstream ecosystem management, including forests, in order to reduce their vulnerability and ensure the quality and quantity of their water supply.
"Adaptation strategies should build on existing local knowledge about forest management in the face of climatic variability, and empower community members to take action to suit their own local circumstances," said Seymour. "For many forest communities, adapting to climate change is already a matter of survival. We need to act now to ensure a better future."
This report, and another CIFOR report on mitigation, will be released on December 5 in Poznán.