Low latitude, high potential: Natural climate solutions in tropical nations
Griscom, B. W., Busch, J., Cook-Patton, S. C., Ellis, P. W., Funk, J., Leavitt, S. M., … & Gurwick, N. P. (2020). National mitigation potential from natural climate solutions in the tropics. Philosophical Transactions of the Royal Society B, 375(1794), 20190126.
The improved stewardship, restoration, and protection of natural ecosystems will be a crucial step in meeting the goals of the Paris agreement. To meet their domestic commitments, approximately two-thirds of countries have incorporated land management strategies into their plans. However, the mitigation potential that these solutions offer is not well known across different geographies. Some researchers have argued that these solutions pose both tradeoffs and synergies with the Sustainable Development Goals but these relationships and costs of implementation have not been comprehensively mapped.
To address these questions, Dr. Bronson Griscom and colleagues estimated the potential contributions of these land management strategies – or natural climate solutions – for over three dozen tropical countries. The authors assessed the opportunity to implement management, protection, and restoration strategies across these countries at costs less than $100 per megagram of carbon dioxide. Solutions that the researchers considered include improved agricultural nutrient management, mangrove restoration, reforestation, forest management, and wetland protection, among others. They found that natural climate solutions in tropical countries could mitigate nearly 20 percent of global emissions at a cost under $100 per ton of carbon dioxide.
Interestingly, the researchers found that the majority of the opportunity lies in improved protection and management of intact ecosystems as opposed to the restoration of degraded ecosystems. Regionally, the greatest potential for tropical natural climate solutions exists in protecting forests within Indonesia, Brazil, and the Democratic Republic of Congo, as well as wetland preservation in Indonesia.
For over a quarter of the countries studied, the potential of cost-effective natural climate solutions is greater than the country’s current emissions. For example, protecting Costa Rica’s existing forests alone could offset nearly twice the country’s emissions. This implies that tropical nations could generate additional income through contributing to other countries’ Paris Agreement commitments, while also progressing toward their Sustainable Development Goals.
The authors’ analysis also considered several factors relevant to implementation including the state of political governance, financial capacity, and the costs and revenues associated with available solutions. In addition to these economic and political metrics, their analysis also incorporates safeguards for land needed for agriculture, textile production, and biodiversity conservation. The inclusion of these safeguards and social components helps to ensure that the estimated capacity of natural climate solutions is consistent with human consumption demands and political realities.
Most importantly, Griscom and colleagues’ work provides a much needed blueprint for countries intending to implement these stewardship solutions and outlines the associated cost. Moreover, distinct from traditional emissions reductions in the power, transportation, and industrials sectors, emissions reductions through natural climate solutions unlock a suite of ecosystem services, through which Sustainable Development Goals can be more effectively attained. While climate commitments remain convoluted, the researchers’ integration of monetary, geophysical, and governance constraints offers clarity on opportunities to finance natural climate solutions in pursuit of regional SDGs and global climate mitigation alike.