https://www.nature.com/articles/s43247-024-01329-3
*Authors* Rhonda C. Müller, Jin-Soo Kim, Hanna Lee, Helene Muri, Jerry Tjiputra, Jin-Ho Yoon & Gabriela Schaepman-Strub *05 April 2024* *Citations*: Müller, R.C., Kim, JS., Lee, H. et al. Radiative forcing geoengineering causes higher risk of wildfires and permafrost thawing over the Arctic regions. Commun Earth Environ 5, 180 (2024). https://doi.org/10.1038/s43247-024-01329-3 *Abstract* Radiative forcing geoengineering is discussed as an intermediate solution to partially offset greenhouse gas-driven warming by altering the Earth’s energy budget. Here we use an Earth System Model to analyse the response in Arctic temperatures to radiative geoengineering applied under the representative concentration pathway 8.5 to decrease the radiative forcing to that achieved under the representative concentration pathway 4.5. The three methods Stratospheric Aerosol Injection, Marine Cloud Brightening, and Cirrus Cloud Thinning, mitigate the global mean temperature rise, however, under our experimental designs, the projected Arctic temperatures are higher than if the same temperature was achieved under emission mitigation. The maximum temperature increase under Cirrus Cloud Thinning and Marine Cloud Brightening is linked to carbon dioxide plant physiological forcing, shifting the system into climatic conditions favouring the development of fires. Under Stratospheric Aerosol Injection, the Arctic land with temperatures permanently below freezing decreased by 7.8% compared to the representative concentration pathway 4.5. This study concludes that these specific radiative forcing geoengineering designs induce less efficient cooling of the Arctic than the global mean and worsen extreme conditions compared to the representative concentration pathway 4.5. Fig. 1: Simulated temperature anomaly in RCP8.5, CCT, MCB and SAI from 2006–2026. [image: figure 1] <https://www.nature.com/articles/s43247-024-01329-3/figures/1> Anomaly in (a) mean (*T*mean), (b) maximum (TXx) and (c) minimum (*T*Nn) land temperature north of 50°N (y-axis) compared to the global mean temperature (*T*glob) anomaly over land and ocean (x-axis). The anomalies are respective to the mean of RCP8.5 from 2006–2026 and are shown for RCP8.5 (grey), RCP4.5 (black), CCT (lime), MCB (red) and SAI (blue). The lines represent the respective ensemble mean. The ensemble spread is shaded. The hatched line represents the 1:1 line. Fig. 4: Change in JJA maximum temperature frequency in CCT and MCB related to fire frequency north of 50°N. [image: figure 4] <https://www.nature.com/articles/s43247-024-01329-3/figures/4> a Conditions under which fires are currently observed in the Arctic54 <https://www.nature.com/articles/s43247-024-01329-3#ref-CR54>,55 <https://www.nature.com/articles/s43247-024-01329-3#ref-CR55>. The anomalies are calculated to 2001–2020. b Maximum temperature frequency north of 50°N of RCP4.5 in 2080–2100. Difference of the maximum temperature frequency between CCT (c) and MCB (d) in 2080–2100 and RCP4.5 in 2080–2100. The hatched line represents the 1:1 line *Source: Nature* -- You received this message because you are subscribed to the Google Groups "geoengineering" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/geoengineering/CAHJsh99tLMVW%3DQe5MBvG0mVC6%3DBH9sbY9n5XzRc8HO%2Be5cysxw%40mail.gmail.com.
