The goal of this document is to offer a concise list of science-based principles to guide deployment of natural climate solutions (NCS) at national and sub-national jurisdictions. The audience includes public policy makers, the private sector, non-government organizations, and donors, all of whom have expectations that NCS can achieve their stated impacts on net greenhouse gas (GHG) emissions without negatively impacting the many services expected from the land and waters of the U.S., especially biodiversity and food production.
These principles represent a consensus of leading organizations with expertise in developing and implementing climate mitigation strategies involving ecosystems and management. In addition, the principles will help avoid specific unintended consequences that could result from deploying NCS. Although the list of principles was developed with U.S. policies and programs in mind, the scope is not limited to U.S. borders, particularly considering that agricultural and forest products have many connections around the world, and that protecting biodiversity is of global concern.
The principles broadly support the inclusion of natural climate solutions that are being formulated by the U.S. government to meet anticipated national targets associated with the Paris Climate Agreement that establishes a global framework to avoid dangerous climate change by limiting warming to less than 2°C. Since it is very unlikely that emissions from fossil fuels can be reduced sufficiently to reach a net zero target by 2050, and since it is becoming necessary to remove some of the carbon dioxide that has already been emitted, “negative emissions” have a significant role to play in limiting warming along with reductions in emissions associated with ecosystem management and land-use change. Land, inland waters, and coastal ecosystems that on balance are now removing about 30% of emissions of carbon dioxide each year have significant potential to continue or even increase this critical function, though it will require careful analysis of options for deploying these natural climate solutions over the next few decades, and monitoring of results which may be affected as impacts of climate change evolve.
The framework underlying these principles includes considerations of time, space, and community. The time dimension recognizes that NCS involve changes in ecosystems and ecosystem management that have impacts that span decades and centuries. The effectiveness of a particular climate solution will vary over these timeframes—some will be effective in the short term, and some in the long term as climate changes and other factors evolve. Likewise, some will be ineffective at times and so the expected benefits as well as co-benefits need to be evaluated now and for the future.
The spatial dimension reflects that ecosystems are highly variable geographically, as are the various factors that influence ecosystems. For example, natural disturbances such as wildfire are much more common and severe in areas where drought and high temperatures are prevalent. Existing management practices are also highly variable, with some regions dominated by agriculture, some by forest management, and some by protection from human-caused disturbances. Potential solutions will be different for these categories, as will the effectiveness of each for reducing greenhouse gas emissions to the atmosphere.
The community or human dimension is critical because NCS will be implemented by people within specific social and economic contexts. All solutions have consequences that go beyond the goal of reducing greenhouse gases, and people will be affected in different ways. Impacts may be positive such as providing jobs or cooling communities by planting trees near buildings, or negative by increasing the costs of goods and services or impacting specific economic sectors such as agriculture and the forest products industry. Therefore, it is essential to evaluate how the different NCS will affect different communities, over different time frames, and in different regions.
