Matteo Luccio in www.sensorsandsystems.com 13 May 2014
anthropogenic CO2 emissions. About 12 percent of these emissions are due to deforestation and forest degradation, mostly in developing countries. To limit forest emissions, in 2008 the United Nations launched its Collaborative Program on Reducing Emissions from Deforestation and Forest Degradation in Developing Countries (UN-REDD). Building on the convening role and technical expertise of the U.N.’s Food and Agriculture Organization (FAO), Development Program (UNDP), and Environment Program (UNEP), it supports nationally-led REDD+ processes and promotes the involvement of all stakeholders, including forest-dependent communities, in national and international REDD+ implementation. UN-REDD is one of the more slowly moving REDD programs because it has 51 partner countries at the table, each with a different perspective on policy.
Above-ground biomass absorbs carbon when trees are alive and releases it when they die or burn. The amount of carbon stored in trees is about half of the dry weight of its biomass. To participate in UN-REDD, a country needs a baseline measurement of the total carbon stock in its above-ground biomass and must then monitor this quantity over time to assess the amount of CO2 that it releases into the atmosphere. If it finds out that it is emitting less CO2 now than in the past, it might be able to get some credit for that. Therefore, the key technical question under the program’s monitoring, reporting, and verification (MRV) provisions is how to monitor the amount of carbon in forests that are being considered under the program, which requires both measuring the height of the forest canopy and understanding the mix of species it contains.
“How to actually know where the carbon in the forest is spatially is turning into one of the biggest challenges,” says Greg Asner, Staff Scientist in the Department of Global Ecology at the Carnegie Institution for Science. In the past, UN-REDD policy allowed for estimation of carbon stocks in forests at the level of large regions or entire countries by sampling for carbon in forest inventory field plots. Nowadays, however, it requires detailed maps of carbon stocks. “Obviously, you cannot produce them with field data alone. So, we’ve been asked many times by governments involved in the UN Framework Convention on Climate Change (UNFCCC) to try to work on the ability to map carbon in a very spatially explicit way.” Without good monitoring it is impossible to implement good policy to sequester carbon in forests. “It would be like having a bank account and depositing money into it without ever getting a proper report from the bank as to whether your money is growing or not.”
One challenge for REDD programs is to make sure that an action taken to conserve carbon in one part of a forest does not simply displace emissions—for example, when loggers, banned from one area, move to another. Ensuring that does not happen would require systematically mapping carbon stocks and emissions throughout the entire surface of all the forests of the world, rather than project-by-project as is currently done.
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