Each year, UNEP releases its Emissions Gap Report comparing the overall scale of countries’ intended actions to reduce greenhouse gas emissions with the total reductions needed to hold global warming below 2°C by the end of the century. The 2015 report includes a special chapter on forest-based mitigation. UN-REDD Programme authors have taken the lead on this chapter, collaborating with CIFOR and others. It covers opportunities to reduce emissions from deforestation and forest degradation, and to enhance forest carbon stocks by restoring degraded forests and re-establishing those that have been lost. As well as contributing to climate change mitigation, all these activities are called for under Sustainable Development Goal 15 (“15.2: By 2020, promote the implementation of sustainable management of all types of forests, halt deforestation, restore degraded forests and substantially increase afforestation and reforestation globally”).
For the 2015 Emissions Gap Report, we estimated the technical potential for each of these broad activities in developing countries. We drew on the literature for reducing deforestation and forest degradation, and did some fresh analysis to identify the potential carbon sequestration that could in principle be possible from wide-scale forest restoration. To do this, we applied standard IPCC biomass accumulation figures for different forest ecosystems to the restoration opportunity areas map from WRI’s Atlas of Forest Restoration Opportunities. The estimated potential across all the “wide-scale forest restoration” area is equivalent to 3.8 GtCO2 in 2030, which is very similar in scale to the estimated emissions reductions that would result from halting deforestation in these countries (3.5 GtCO2 in 2030). Reducing degradation in standing forests, through sustainable forest management, fire control and other measures can further contribute to climate change mitigation.
Shortly after presenting on these findings at a Rio Convention Pavilion session on forest and landscape restoration in Paris on the margins of COP21, I listened to Detlef van Vuuren from the PBL Netherlands Environmental Assessment Agency providing some insights on land-based mitigation from scenarios and integrated assessment models. It was striking to hear that “most models” anticipate that to meet a 2°C target, the world will need to sequester around 2 to 4 GtCO2 per year through afforestation (and reforestation) in the period up to 2050. Our calculations suggest that this is approximately equivalent to reforesting all of the area included in the above analysis for wide-scale forest restoration in developing countries– around 350 million hectares.
The forest landscape restoration ambitions described so far by developing countries often involve mosaic restoration approaches that seek to include more trees across agricultural landscapes in a way that meets local needs. This might involve expanding agroforestry, planting new woodlots or restoring forests critical for ecosystem services. Compared to our simple analysis on the reforestation of large areas, this means that in reality we can expect a much more diverse set of approaches over a greater land area to be involved in meeting the global mitigation target.
The “intended nationally determined contributions” documents of developing countries, prepared under the climate convention, often emphasize the need for international financial support to enable forest-related mitigation, and some funders are stepping up to the mark to support REDD+ efforts. Ahead of COP21, developing countries had already stated an intention to restore, afforest or reforest at least 141 million hectares of land, including through mosaic and wide-scale restoration. This figure is the sum of the largest restoration area any given country had proposed under different fora, including the INDCs and the Bonn Challenge. During the COP, an additional 15 million hectares were pledged above and beyond those included in any existing national statements. These were announced under the Bonn Challenge and two associated endeavours, the AFR100 initiative and Initiative 2020. Asia Pulp and Paper also made a pledge of 1 million hectares, the first private-sector led contribution to the Bonn Challenge.
The growing momentum behind forest landscape restoration shows that it is a significant opportunity – and if the models are to be believed, an essential strategy – to help narrow the emissions gap and limit the global average increase in temperatures to less than 2°C by 2100. As world leaders have now committed under the Paris Agreement to pursue efforts to limit the increase to 1.5°C above pre-industrial levels, our forests may be needed more than ever.
Lera Miles is based at the United Nations Environment Programme World Conservation Monitoring Centre (UNEP-WCMC), coordinating its work on REDD+ benefits and safeguards in support of the UN-REDD Programme.