Reducing deforestation to mitigate climate change necessitates monitoring of deforestation activity. However, while freely available deforestation alerts on forest loss are available, the effect of these alerts and the presence of subscribers in a particular area is unclear. Here, we show that subscriptions to alerts in 22 tropical countries decrease the probability of deforestation in Africa by 18% relative to the average 2011–2016 levels. There is no effect on other continents, and the availability of alerts does not significantly change deforestation outcomes. This decrease in Africa is higher in protected areas and concessions, suggesting that alerts either increased capacity to enforce existing deforestation policy or induced the development of more effective anti-deforestation policies. Calculated using the social cost of carbon for avoided deforestation in Africa, we estimate the alert system’s value to be between US$149 million and US$696 million.

减少森林砍伐以缓解气候变化需要对森林砍伐活动进行监测。然而，虽然可以免费获得关于森林丧失的毁林警报，但这些警报的影响以及特定地区的订阅者的存在尚不清楚。在这里，我们展示了在 22 个热带国家订阅警报，相对于 2011-2016 年的平均水平，非洲森林砍伐的可能性降低了 18%。对其他大陆没有影响，警报的可用性不会显着改变森林砍伐结果。非洲保护区和特许权的减少幅度更大，这表明警报要么提高了执行现有森林砍伐政策的能力，要么促使制定了更有效的反森林砍伐政策。