Hurricanes pose a substantial risk to New England forest carbon stocks

• Published in: Global change biology 2024-04, Vol.30 (4), p.e17259-n/a
• Main Authors: Tumber‐Dávila, Shersingh Joseph, Lucey, Taylor, Boose, Emery R., Laflower, Danelle, León‐Sáenz, Agustín, Wilson, Barry T., MacLean, Meghan Graham, Thompson, Jonathan R.
• Format: Article
• Language: English
• Subjects: Carbon; Carbon - analysis; carbon offsets; Carbon Sequestration; Carbon sinks; Climate Change; Climate change mitigation; Climate policy; Cyclonic Storms; Damage; Disturbances; Emissions; forest carbon; Forests; future climate change; Hurricanes; Models, Theoretical; nature‐based climate solutions; New England; Policies; Sequestering; Stocks; Wind; wind damage; Wind speed
• ISSN: 1354-1013; 1365-2486
• DOI: 10.1111/gcb.17259

Nature‐based climate solutions (NCS) are championed as a primary tool to mitigate climate change, especially in forested regions capable of storing and sequestering vast amounts of carbon. New England is one of the most heavily forested regions in the United States (>75% forested by land area), and forest carbon is a significant component of climate mitigation policies. Large infrequent disturbances, such as hurricanes, are a major source of uncertainty and risk for policies relying on forest carbon for climate mitigation, especially as climate change is projected to alter the intensity and extent of hurricanes. To date, most research into disturbance impacts on forest carbon stocks has focused on fire. Here, we show that a single hurricane in the region can down between 121 and 250 MMTCO2e or 4.6%–9.4% of the total aboveground forest carbon, much greater than the carbon sequestered annually by New England's forests (16 MMTCO2e year−1). However, emissions from hurricanes are not instantaneous; it takes approximately 19 years for downed carbon to become a net emission and 100 years for 90% of the downed carbon to be emitted. Reconstructing hurricanes with the HURRECON and EXPOS models across a range of historical and projected wind speeds, we find that an 8% and 16% increase in hurricane wind speeds leads to a 10.7‐ and 24.8‐fold increase in the extent of high‐severity damaged areas (widespread tree mortality). Increased wind speed also leads to unprecedented geographical shifts in damage, both inland and northward, into heavily forested regions traditionally less affected by hurricanes. Given that a single hurricane can emit the equivalent of 10+ years of carbon sequestered by forests in New England, the status of these forests as a durable carbon sink is uncertain. Understanding the risks to forest carbon stocks from disturbances is necessary for decision‐makers relying on forests as a NCS. Forests are being championed as nature‐based climate solutions, especially in heavily forested regions such as New England. However, disturbances, such as hurricanes, are a major source of uncertainty and risk for policies relying on forest carbon for climate mitigation. Using hurricane reconstructions across a range of wind speed projections, we find that a single hurricane can emit the equivalent of 10+ years of carbon sequestered by forests in New England, an average of 5%–10% of total aboveground forest carbon.