The economic value of tropical forests in meeting global climate stabilization goals

Non-technical summary Conserving tropical forests has many benefits, from protecting biodiversity, sustaining indigenous and local communities, and safeguarding climate. To achieve the ambitious climate goals of the Paris Agreement, forest protection is essential. Yet deforestation continues to diminish the world's forests. Halting this trend is the objective of the international framework for Reducing Emissions from Deforestation and forest Degradation (REDD+). While previous studies have demonstrated the contribution of tropical forests to mitigate climate change, here we show that tropical forest protection can 'flatten the curve' of the costs of transition to climate stability, estimating tens of trillions of dollars in policy cost savings. Technical summary The pledges made by parties under the Paris Agreement are insufficient to limit global warming to well below 2 °C relative to pre-industrial levels. We use a global climate-economic model to quantify the economic benefits from rapidly deploying programs for reducing emissions from deforestation and forest degradation and increased reforestation (REDD+) given current delays in the implementation of climate policies around the world. REDD+ has been shown to have substantial greenhouse gas emissions mitigation potential in the fight against climate change and can thus play a critical role in closing the emissions gap, thereby enabling the achievement of more ambitious climate targets. Under our principal scenario, we estimate that REDD+ can contribute up to US$36 trillion in net policy cost savings by mitigating the adjustment costs of reaching a greenhouse gas emissions trajectory consistent with ambitious global climate stabilization goals. Investment in REDD+ has a high benefit-cost ratio; one dollar invested in REDD+ yields about US$5.4 in net policy cost savings. Realizing the full estimated potential for REDD+ reduces the risk-adjusted carbon price in 2030 by US$45/tCO2. Social media summary Protecting tropical forests is crucial to achieve ambitious climate stabilization goals while saving trillions of dollars in economic value.