At its October meeting in Batumi, Georgia, the Intergovernmental Panel on Climate Change (IPCC) adopted a new Methodology Report, prepared by its Task Force on National Greenhouse Gas Inventories (TFI). The 2013 Supplement to the 2006 IPCC Guidelines for National Greenhouse Gas Inventories: Wetlands (Wetlands Supplement) provides new guidance for countries to cover wetlands. The Supplement will be published on the TFI website on 2 November.

We’ve put together this overview on why and how the Supplement was made and what it means for countries and their climate change mitigation strategies, drawing on information from three of the experts who spent hundreds of hours over the past few years writing, reviewing and revising the new guidelines: Louis Verchot, research director at the Center for International Forestry Research (CIFOR), Daniel Murdiyarso, principal scientist at CIFOR and Boone Kauffman of Oregon State University.

What is the “Wetlands Supplement”?

The new methodology report is a supplement to the Agriculture, Forestry and Land Use (AFOLU) volume of the 2006 IPCC Guidelines for Greenhouse Gas Inventories. The IPCC guidelines are a comprehensive set of methods for inventorying greenhouse gas emissions and removals for all sectors, from industry and waste management to agriculture and forestry.

The fact that the IPCC adopted these guidelines means that governments unanimously accepted them, so now following them is mandatory.

What was the process for making the guidelines?

The IPCC draws on robust scientific data to create comprehensive guidelines, which provide de facto international standards for estimations of emissions and removals of greenhouse gases. The IPCC then updates these guidelines as new science becomes available. The 2013 Wetlands Supplement is an example of an update. The supplement was commissioned in 2010 and was approved after two rounds of reviews by scientific experts and two rounds of reviews by governments. Governments subjected the report to a final round of scrutiny in Batumi, Georgia, before approving the report for use.

What is the Wetlands Supplement used for?

National governments currently have to complete and report their national greenhouse gas inventories periodically in their National Communications to the UNFCCC. Developed countries report more frequently than developing countries because of their greater capacity, but from 2020, all countries will be required to submit a report every two years.

The inventories assess emissions and the removals of greenhouse gases from the atmosphere. As such, they provide essential information to scientists, policy makers and other stakeholders concerned with mitigating climate change. Countries can use the estimates to develop their climate policy and to inform their position in global climate negotiations.

All countries are obliged to follow the reporting guidelines set by the IPCC. However, until now, reporting on emissions and removals from high-Carbon ecosystems — primarily peatlands and mangroves — had been missing from the IPCC Guidelines. The Wetlands Supplement ensures that, from next year, countries will start including emissions from wetlands in their national inventories.

Who will use the Wetlands Supplement?

Every country that has wetlands will have to use the Supplement — which is pretty much every country in the world. However, countries will use the guidelines differently depending on how important emissions from wetlands are to their inventory. These guidelines will be of particular use to the 50 or so countries across the tropics that have peatlands and that have significant land-use activities in peatlands.

For countries where wetlands do not make a major contribution to national emissions, the guidelines provide a minimum set of information to enable them to complete their inventories. These minimums, or default values, are known as the Tier 1 values. Countries estimate the area of their wetlands and then use the default values given in the guidelines to calculate the final count.

Countries where wetlands are a major source of national emissions have to go beyond the minimum and conduct more sophisticated inventories, using Tier 2 or 3 values; these guidelines tell these countries how to go about doing this.

What effect will these guidelines ultimately have?

The new guidelines effectively create a mandate for governments to improve their reporting of greenhouse gas emissions from wetlands. Ultimately, this will put pressure on governments to address emissions from agriculture and other activities on wetlands that are causing emissions.

These guidelines are the first step in helping countries to do this. Countries that are trying to achieve emission reductions from land use must first determine where their emissions are. If they can’t do this, then they can’t calculate the volume of their emissions from wetlands. If they can’t calculate the volume of their emissions from wetlands, they can’t plan and take actions to reduce them.

All reporting is done in a very transparent manner, which ensures the effectiveness of the process. Once countries put the emissions into their national inventory, they are reporting those numbers to the whole world, and thus become open to international scrutiny.

Why weren’t wetlands included in the 2006 Guidelines?

Until recently, there was a dearth of data of sufficient quality and geographical distribution to generate representative emission factors for the inventories. Since 2006, that has changed. Most of the data used to generate the emission factors used in the guidelines were released from 2008 onward.

In the early 2000s, papers on wetlands — tropical, temperate and boreal — began to appear, as research efforts intensified. (A major trigger for this attention to peatlands was the fires in Indonesia in 1997–98.) As the research findings came in, they confirmed what had been suspected — that peatlands and mangroves have very high carbon stocks.

The research that was conducted made a very valuable contribution to helping the world overcome some major technical hurdles. Not all questions have been answered, but the data are good enough for countries to begin quantifying their emissions. Researchers will continue to collect data and test more hypotheses, and build a better understanding of these ecosystems.