Abstract
As a carbon dioxide removal measure, the Norwegian government is currently considering a policy of large-scale planting of spruce (Picea abies (L) H. Karst) on lands in various states of natural transition to a forest dominated by deciduous broadleaved tree species. Given the aspiration to bring emissions on balance with removals in the latter half of the 21st century in effort to limit the global mean temperature rise to "well below" 2°C, the effectiveness of such a policy is unclear given relatively low spruce growth rates in the region. Further convoluting the picture is the magnitude and relevance of surface albedo changes linked to such projects, which typically counteract the benefits of an enhanced forest CO2 sink in high-latitude regions. Here, we carry out a rigorous empirically based assessment of the terrestrial carbon dioxide removal (tCDR) potential of large-scale spruce planting in Norway, taking into account transient developments in both terrestrial carbon sinks and surface albedo over the 21st century and beyond. We find that surface albedo changes would likely play a negligible role in counteracting tCDR, yet given low forest growth rates in the region, notable tCDR benefits from such projects would not be realized until the second half of the 21st century, with maximum benefits occurring even later around 2150. We estimate Norway's total accumulated tCDR potential at 2100 and 2150 (including surface albedo changes) to be 447 (±240) and 852 (±295)MtCO2 -eq. at mean net present values of US$ 12 (±3) and US$ 13 (±2) per ton CDR, respectively. For perspective, the accumulated tCDR potential at 2100 represents around 8years of Norway's total current annual production-based (i.e., territorial) CO2 -eq. emissions.
Highlights
Balancing CO2 emissions and removals by the latter half of the 21st century aligns with ambitious efforts ascribed under the Paris Agreement to limit global mean temperature increases to “well below 2°C” from pre-industrial levels
We find that surface albedo changes would likely play a negligible role in counteracting terrestrial carbon dioxide removal (tCDR), yet given low forest growth rates in the region, notable tCDR benefits from such projects would not be realized until the second half of the 21st century, with maximum benefits occurring even later around 2150
We estimate even greater reductions at 2100 when spruce is planted on area presently classified at open (i.e., accelerated forest conversion (AFC) projects)—or −661 (±302) t CO2/ha—which is offset on average by 40 (±25) t CO2-eq./ha due to the surface albedo change
Summary
Balancing CO2 emissions and removals by the latter half of the 21st century aligns with ambitious efforts ascribed under the Paris Agreement to limit global mean temperature increases to “well below 2°C” from pre-industrial levels. Aggressive mitigation of total emissions by 2050 coupled with substantial carbon dioxide removal is required to increase the chance of limiting warming to 1.5°C and 2°C by 2100 (Roe et al, 2019, Rogelj et al, 2018), and land sector measures alone could sustainably contribute around 30% (~15 Gt CO2-eq./year) of the required mitigation needed by mid-century to limit the increase to 1.5°C with zero overshoot (Roe et al, 2019). More recent bottom-up estimates put the combined mitigation potential from both aff-/reforestation and IFM at around 5.75 Gt CO2-eq./ year (“roadmap” potential of Roe et al, 2019)—which is around 12% of the total mitigation needed by 2050 to limit warming to 1.5°C with no overshoot (66% confidence)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
