Forests and agriculture can get us at least a quarter of the way to meeting the Paris Agreement’s goal of limiting warming to 1.5 °C. While a rapid decarbonization of the global economy remains essential, aggressive action to reduce emissions from the land sector can buy additional time for this transition.
Maximizing mitigation from forests and agriculture requires protecting and restoring forests, improving agricultural practices, and shifting to more sustainable diets. This can enhance the role of the land sector as a carbon sink.
Levels of funding for political attention to forests and land use do not reflect their essential role in our global response to climate change.
A Bridge to a Fossil-Free World
• To avoid the worst impacts of climate change, the Paris Agreement aims to limit the average global temperature increase to 1.5 °C above pre-industrial levels. Despite existing efforts, we are not on track to our climate requires more ambitious action, and forests and agriculture have an important and underappreciated role to play.
• Forests already remove around 30% of human-produced carbon dioxide emissions from the atmosphere, and with efforts to maximize their role as a carbon sink, they can remove much
more. To meet the goals of the Paris Agreement, deep reductions in fossil fuel emissions must be
accompanied by rapid increases in the removal of carbon dioxide emissions from the atmosphere. We can manage forests and other land to reduce emissions and enhance this carbon sink capacity.
• While a rapid decarbonization of the global economy remains essential, ending deforestation, allowing damaged forests to grow back, and leaving mature forests undisturbed can buy additional time for this energy transition to take place. In fact, ending tropical forest loss, improving tropical forest management, and restoring 500 million hectares of tropical forests could reduce sufficient emissions to provide 10-15 years of additional time to dramatically reduce our use potential is even larger if the role of the entire land use sector is considered.
• Forests and agriculture can get us at least a quarter of the way to meeting the Paris Agreement’s 1.5-degree Celsius goal. For this to happen, net emissions from the land sector must peak by 2020, reach zero between 2040 and 2050, and become negative afterward. Achieving ‘net negative’ emissions—meaning the land sector absorbs more carbon from the atmosphere than it emits—requires dramatic reductions in deforestation, forest degradation, and peatland loss; forest restoration and improved forest management; and more sustainable agricultural systems. This last category includes changing the way we both produce and consume food, by increasing soil carbon sequestration and reducing on-farm emissions while also ending food waste and shifting toward more sustainable diets.
• Capturing more carbon in land and forests is a critical component of any plan to tackle global warming. It is not a substitute for eliminating our dependence on fossil fuels. But together, the near-term deployment of our collective forest and land use asset can begin significantly larger-scale carbon removal while policies and technologies are rapidly developed to constrain and eventually end fossil fuels use.
Unrealized Carbon Sinks
• Forests and lands both emit and remove carbon from the atmosphere. This unique characteristic has obscured the importance of the land use sector for climate change mitigation, because emissions and removals are lumped together rather than treated separately.
• The figure illustrates how this hides significant opportunities for emissions reductions and the full scale of the carbon removals potentially available.
o In net terms (subtracting total removals from total emissions), land use is responsible for only around 10% of carbon emissions, but gross land use emissions by themselves are responsible for approximately 37% of the total.
o On the other hand, gross land use removals are responsible for 30% of negative emissions but, when added to the residual land removals (primarily from unmanaged forests), terrestrial ecosystems remove 51% of anthropogenic carbon emissions.
o Looking at the full value of carbon removals (rather than subtracting removals from the emissions) would give a better sense of the mitigation potential of the land use sector
THE POTENTIAL OF FORESTS
With appropriate action, the cumulative size of the forest sink could increase by 100 billion metric tons of carbon by the 6 year 2100 – significantly larger than it is today. There are three primary ways we can use forests to help mitigate climate change:
1. Stopping deforestation—ending the loss of forest area.
2. Improving forest management and reducing forest degradation (the smaller scale removal of trees from standing forests). New research indicates that degradation is responsible for 70% of forest loss in the
3. Allowing forests to grow back in areas that have been deforested, either through natural regeneration or by planting trees. Past efforts at afforestation (establishing forests on land not previously forested), reforestation (renewing forest cover on previously forested land), and forest restoration (improving forest condition, tree cover, and carbon stocks) offer models.
For example, efforts to plant, replant and restore forests in South Korea, China, and India have removed more than 3.3 billion metric tons of carbon from the atmosphere These programs, however, need to be part of a long-term strategy to ensure that their sequestration potential is realized.
Scientists estimate net emissions of 1.1 billion metric tons of carbon from forested areas and land use each year. But, this net figure obscures the magnitude of the opportunity: 5.5 billion metric tons of carbon is released through deforestation and degradation, while 4.4 billion metric tons of carbon is absorbed through standing forests on managed lands. For perspective, that 4.4 billion metric tons is 18 times the annual emissions from all cars and trucks in the United States. Maximizing the contribution of forests to climate change mitigation requires bringing the 5.5 billion metric tons of annual emissions from deforestation and degradation close to zero. But it also requires maintaining the 4.4 billion metric tons of carbon absorbed by forests each year, by improving the management of existing forests and increasing forest area. With increased efforts to manage the land for carbon, the cumulative forest sink could increase by 100 billion metric tons of carbon by 2100, equivalent to a decade of global fossil fuel use at today’s rates of emissions.
Forests also provide significant climate benefits beyond avoiding and removing greenhouse gas emissions. For example, they play an important role in regulating climate locally by cooling the Earth’s evidence shows deforestation directly alters local and of millions of indigenous peoples and local communities also depend directly on forests for their livelihoods, and securing their land and resource rights is a proven strategy for avoiding deforestation.