Estimating Climate Change Mitigation Potential Through Dryland Forestation Actions
Shani Rohatyn-Blitz, KKL-JNF
Please join us for our next Monday departmental seminar on the 19th of December from 15:00 to 16:00 at the Porter Auditorium
Estimating Climate Change Mitigation Potential Through Dryland Forestation Actions
Shani Rohatyn-Blitz, KKL-JNF
Given the capacity of dryland forests and soils to sequester carbon dioxide, large-scale afforestation of dryland areas has the potential to mitigate global warming. Forestation actions in drylands are widely used to combat desertification, and as a means for climate mitigation. However, forestation has contrasting effects on the climate. Forest carbon sequestration has a cooling effect, but the typical decrease in albedo following forestation has a warming effect. The actual climatic benefit from large-scale forestation actions in drylands is still unknown, and in some areas, the net effect of forestation may be warming. In view of the large potential carbon sink in global drylands, combined with the relative paucity of studies on this topic, dryland forestation effects are the focus of this seminar. In my work, I aim to estimate the potential of drylands to support large-scale forestation actions as a climate mitigation tool. I quantify the maximum expected climatic benefits from afforestation, of the entire semi-arid and dry sub-humid biomes. I estimated both carbon cooling potential and albedo warming effects and simulated the expected cumulative effects on climate until the end of the century (i.e. 80 years of forestation). I found that the global mitigation potential of dryland afforestation is small compared to the projected emissions rate for the same period. Afforestation of 450 Mha would offset less than 1% of the projected emissions for the business-as- usual scenario. These estimates are more than three times lower than most previous estimates, in which albedo effects are not accounted for. Interestingly, if afforestation is limited to areas with a net cooling effect, the capacity for climate mitigation rises significantly. Overall, I identify 250 Mha of drylands that may have cooling mitigation effects. These findings highlight the need to include the albedo warming effect in dryland forestation initiatives, and the importance of robust, spatially explicit assessment of the contribution of large-scale projects before taking action
Bio
Dr. Shani Rohatyn-Blitz received her M.Sc from the Faculty of Agriculture Food and Environment at the Hebrew University of Jerusalem. Her thesis dealt with alterations in the ecosystem water cycle associated with land-use changes under different precipitation regimes. Her doctorate thesis at the Faculty of Civil and Environmental Engineering at the Technion – Israel Institute of Technology - evaluated the potential benefit of large-scale dryland forestation action as a climate-change mitigation strategy. Shani joined KKL-JNF for the “new foresters” training in the summer of 2021. For the past year, she has served as the coordinator for research and external relations in the forestry division
Alon Shepon
The Department of Environmental Studies
The Porter School of the Environment and Earth Science
Tel Aviv University | website
The Israeli Forum for Sustainable Nutrition
