Planting forests for carbon sequestration

Using forest projects to mitigate global warming by increasing the global uptake of carbon from the atmosphere.

Global CO2 emissions from sources such as car exhausts and industry are predicted to double between now and 2050. More CO2 means that trees will grow faster and lock up more carbon. This led some to hope that plants might mop up all the extra gas.

This strategy features in the framework of Agenda 21 as formulated at UNCED (Rio de Janeiro, 1992), now coordinated by the United Nations Commission on Sustainable Development and implemented through national and local authorities.

Agenda 21 recommends compiling and analysing research data on species/site interaction of species used in planted forests and assessing the potential impact on forests of climatic change, as well as effects of forests on climate, and initiating in-depth studies on the carbon cycle relating to different forest types to provide scientific advice and technical support.

The 1995 Inter-governmental Panel on Climate Change (IPCC) assessment states that if various measures are implemented in the forestry sector, it is estimated that between 1.1 and 1.8 Gt C per year can be sequestered in 50 years. As such, the possibility of emission reductions in forestry and the potential for increasing carbon sequestration gives the sector an elevated role in measures to mitigate climate change.

The United Nations Framework Convention on Climate Change (UNFCCC) was established in 1992 at the United Nations Conference on Environment and Development (UNCED) held in Rio de Janeiro, Brazil. Its main objective is to stabilize atmospheric greenhouse gases (GHG) concentration at a level that would prevent dangerous anthropogenic interference with the climate system." The Convention is a treaty which provides a framework of principles and processes through which subsequent protocols or specific mechanisms and actions can be developed and agreed. The Kyoto Protocol, which emanated from the Third Conference of the Parties (COP3) to the UNFCCC held in Kyoto, Japan in December 1997, is one such agreement.

The Netherlands Face Foundation is using the mechanism of "joint implementation", under the [Framework Climate Convention on Climate Change], to increase its global carbon sinks. Face is an acronym for "Forests Absorbing Carbon Dioxide Emissions" and was founded in 1990 by the Dutch Electricity Generating Board with the objective of planting forests in order to compensate for the emissions of carbon dioxide (CO₂0 in the Netherlands. It plans to finance 150,000 hectares of new forest in the next 25 years which will fix 75 million tonnes of CO₂ -- as much as a 600 MW coal-fired power station will emit in its lifetime. The first Face projects started in 1992. Apart from four small afforestation projects in the Netherlands, the Foundation has contributed to the maintenance of 16,000 hectares of forest in the Krkonose National Park in the Czech Republic and the restoration of 25,000 of forest on Sabah, Malaysia. Some 75,000 hectares are being reforested on the slopes of the Ecuadorian Andes and 27,000 hectares of degenerated rain forest are being reforested on Kalimantan, Indonesia.

While some terrestrial sources are likely to increase CO₂ emissions due to warmer climates and expanding agriculture, increased international actions to sequester carbon in forests and soils and continued increase in carbon dioxide fertilization effects could more than offset them. (At least twice as much carbon is locked in soils than above ground in natural vegetation.) Studies suggest that total terrestrial sequestration over the next century may vary from 75 to more than 700 GtC, depending on the emissions and source/sink scenarios used.

The world cannot rely on trees to solve the problem of CO2 emissions. Forests will be less effective at slowing climate change than expected. A four-year experiment placed trees in a CO2-enriched atmosphere mimicing that predicted for 2050. They converted 27% more carbon dioxide into plant matter than at control sites. However, even if this extra growth occurs in existing temperate forests all over the world in 2050, the trees will only absorb 10 per cent of human-generated CO2.