Presentation by Dr. Werner A. Kurz, Senior Research Scientist, Canadian Forest Service, Natural Resources Canada. Victoria, BC, Canada. e-mail: werner.kurz@canada.ca
Summary
North America’s forest sector is expected to contribute to mitigating climate change by reducing sources or increasing sinks of atmospheric greenhouse gases (GHG). The Intergovernmental Panel on Climate Change (IPCC) has emphasized that assessments of the mitigation potential in the forest sector should be based on estimates of carbon stock changes and the resulting GHG emissions in forest ecosystems, in the harvested wood product (HWP) sector and of the avoided emissions that result from the substitution of emissions-intensive products such as steel and concrete with HWPs. Integrated assessments conducted in Canada that follow these principles indicate a significant and increasing potential for climate change mitigation in the forest sector, provided that mitigation activities are implemented soon. The analyses also demonstrate the need to avoid simplifying accounting assumptions such as instant oxidation of HWP or carbon neutrality of bioenergy when designing climate effective mitigation portfolios. Kurz's research also finds that the climate mitigation benefits increase through cascading use of wood products derived from sustainably managed forests and used to maximize the avoided emissions and longevity of the HWP. Current research also focuses on the interaction between climate change impacts on forest ecosystems and regionally-differentiated forest sector mitigation portfolios that are designed to anticipate climate change impacts, and meet both adaptation and mitigation objectives.
Biography
Dr. Werner Kurz is a Senior Research Scientist at the Canadian Forest Service (Natural Resources Canada)in Victoria, British Columbia. He leads the development of Canada's National Forest Carbon Monitoring, Accounting and Reporting System and the Forest Carbon Management Project of the Pacific Institute for Climate Solutions. His research focuses on carbon dynamics in forests and harvested wood products and the opportunities of the forest sector to contribute to climate change mitigation. Dr. Kurz co-authored six reports of the Intergovernmental Panel on Climate Change (IPCC). He serves as adjunct professor at the University of British Columbia (UBC) and at Simon Fraser University. He obtained his PhD in Forest Ecology from UBC and an honorary doctorate from the Swedish Land University.
Abstract
The potential of forests and the forest sector to mitigate greenhouse gas (GHG) emissions is widely recognized, but challenging to quantify at a national scale. Forests and their carbon (C) sequestration potential are affected by management practices, where wood harvesting transfers C out of the forest into products, and subsequent regrowth allows further C sequestration. Here we determine the mitigation potential of the 2.3 × 106 km2 of Canada's managed forests from 2015 to 2050 using the Carbon Budget Model of the Canadian Forest Sector (CBM-CFS3), a harvested wood products (HWP) model that estimates emissions based on product half-life decay times, and an account of emission substitution benefits from the use of wood products and bioenergy. We examine several mitigation scenarios with different assumptions about forest management activity levels relative to a base case scenario, including improved growth from silvicultural activities, increased harvest and residue management for bioenergy, and reduced harvest for conservation. We combine forest management options with two mitigation scenarios for harvested wood product use involving an increase in either long-lived products or bioenergy uses. Results demonstrate large differences among alternative scenarios, and we identify potential mitigation scenarios with increasing benefits to the atmosphere for many decades into the future, as well as scenarios with no net benefit over many decades. The greatest mitigation impact was achieved through a mix of strategies that varied across the country and had cumulative mitigation of 254 Tg CO2e in 2030, and 1180 Tg CO2e in 2050. There was a trade-off between short-term and long-term goals, in that maximizing short-term emissions reduction could reduce the forest sector's ability to contribute to longer-term objectives. We conclude that (i) national-scale forest sector mitigation options need to be assessed rigorously from a systems perspective to avoid the development of policies that deliver no net benefits to the atmosphere, (ii) a mix of strategies implemented across the country achieves the greatest mitigation impact, and (iii) because of the time delays in achieving carbon benefits for many forest-based mitigation activities, future contributions of the forest sector to climate mitigation can be maximized if implemented soon.