Aotearoa New Zealand's 21st‐Century Wildfire Climate

• Published in: Earth's future 2022-06, Vol.10 (6), p.n/a
• Main Authors: Melia, N., Dean, S., Pearce, H. G., Harrington, L., Frame, D. J., Strand, T.
• Format: Article
• Language: English
• Subjects: Afforestation; Bias; bushfire; Climate change; Climate change mitigation; Climate models; Climatic analysis; emergence; Emissions; Environmental policy; Extreme weather; fire; Forest management; FWI; Humidity; New Zealand; Paris Agreement; Precipitation; Rain; Regional climate models; Regional climates; Regions; Temperature; Trends; Variables; Weather; Weather conditions; Wildfire; Wildfires
• ISSN: 2328-4277; 2328-4277
• DOI: 10.1029/2022EF002853

Wildfire is a highly variable natural phenomenon, yet despite this, climate change is already making wildfire conditions measurably worse around the world; however, detailed knowledge about Aotearoa New Zealand's wildfire climate is currently limited. This study blends weather observations with regional climate model projections to assess Aotearoa New Zealand's 21st‐century wildfire climate. We find that in the 21st‐century, the emergence of a new—more severe wildfire climate will occur. Detailed analysis of observed and simulated wildfire weather finds that “very‐extreme” wildfire weather conditions matching the levels observed in Australia's 2019/2020 “Black Summer” bushfires are possible in regions formerly unaffected. While the extent of emergence is dependent on future emissions, the frequency of very‐extreme conditions for the areas affected can occur at any time and is independent of projected 21st‐century climate changes. Our findings have significant implications for many rural fire authorities, forest managers and investors, and climate mitigation and afforestation programs. Plain Language Summary Combining highly detailed climate simulations with daily observations of weather and wildfire conditions, we simulate Aotearoa New Zealand's current and future wildfire weather conditions. We find that wildfire weather conditions will increase on average, both in wildfire season length and in the intensity of fires that may take hold, with the most severe wildfire dangers in the central‐south inland areas of the South Island. We find that the wildfire weather conditions will become noticeably worse for many regions than current conditions. For the first time, we find that very‐extreme conditions that led to the devastating 2019–2020 “Black‐Summer” fires in Australia can occur in Aotearoa every 3–20 year for areas of the South Island (Mackenzie Country, Upper Otago, and Marlborough). Our findings have important implications for communities near pine forests, the Government's tree planting plan to tackle climate change, and financial investment stored in plantation forests. Key Points In the 21st‐century, the emergence of a new—more severe wildfire climate will occur We discover that “very‐extreme” wildfire weather conditions are possible in regions formerly unaffected While the extent of emergence is dependent on future emissions, the frequency of very‐extreme conditions is independent