Forest carbon sequestration and climate change Dr Brian Tobin University College Dublin
Overview Sequestration what is it & why important? Role of forests in climate change CARBiFOR research project Forest biomass and carbon Role of afforestation & sequestration
Context: Climate change increasing rate driven by anthropogenic emissions Increasing atmospheric carbon dioxide concentration leading to global warming No longer any doubt proof all around us Carbon sequestration Proof of global warming! The net removal from the atmosphere of carbon dioxide, and storage in plant biomass (e.g. in the form of increasing forests or in other reservoirs such as soil, geological formations, oceans, wood products, etc.) Photosynthesis Respiration = Sequestration
Tree growth Solar radiation Carbon dioxide Oxygen Water Carbon dioxide Nutrients Wood/Timber
Mitigation of climate change? To decrease sources and increase sinks! Options: Renewable energy Energy efficiency & conservation Nuclear power Transport, urban planning and design Carbon air capture, CCS and scrubbers in factory chimney stacks Societal and population control Reforestation and avoided deforestation Forest carbon sequestration
Role of forests in climate change mitigation: Sequestration in new forest stocks (5 pools) Conservation of existing forests (avoiding degradation and deforestation) HWP stock pool (life span important) Energy source (carbon neutral) Substitution for other fossil fuels Harvested Wood Products
Climate change & Irish forestry Impacts Species distribution / suitability Productivity Pests and diseases Frequency of extreme climatic events Understanding of effects required before suitable adaptive strategies can be developed
Species suitability Black et al., 2010
Species suitability Black et al., 2010
CARBiFOR Carbon sequestration in Irish Forest ecosystems Common species, typical of commercial forestry Chronosequence approach Focus on the ecosystem Web: http://www.ucd.ie/carbifor/index.html
Measuring forest productivity Eddy covariance Ecosystem approach Biomass sampling Soil sampling Respiration chambers Litter collection sampling
Sample trees: Stem Bark Different components or tissue types Biomass Sampling Dead branches Live Foliage Roots Chronosequence of sites Component samples used to determine: Moisture content, basic density and carbon content
Root Excavation:
Biomass distribution Per tree Biomass allocation (% dry biomass) to tree components across the chronosequence.
Carbon fraction Tree Component C -fraction (%) Mean 95% Confidence interval Total tree 50.24 0.14 Root 48.99 0.19 Stem wood 49.90 0.24 Bark 51.30 0.25 Branches 51.06 0.17 Dead branches 51.31 0.29 Needles 51.57 0.16 Stem & Bark 50.16 0.21 Foliage 51.39 0.14 IPCC GPG default = 50%
Forest ecosystem carbon balance Units of NEP: T C ha 1 year 1 5 carbon pools: Aboveground Belowground Deadwood Litter Soil Black & Farrell, 2006
Other land uses
Forests in Ireland Forests cover 10% of total land area Public 57%; Private 43% Total stocked forest area 625,750 ha Conifer 73.9% Broadleaf 24.3% Temporarily unstocked 1.8% 2/3 of estate 20 years old or less NFI, 2007
Carbon uptake in Irish forests 6.2 MT CO 2 ha per year (1.96 T CO 2 per second) Harvest removals 2.6 MT Net removal from atmosphere of 3.6 MT CO 2 Kyoto forests 2.63 MT CO 2 for 2010 (valued at 40M) BUT
Sequestration through afforestation is finite, potentially short term, One rotation and reversible. 5 rotations After one rotation C sequestration reaches ± steady state. Therefore afforestation effect is once off Is it worth it??? Is it sustainable?
Mitigation of emissions Sustainable? Bioenergy and products Forestry Commission, 2003
25,000 20,000 15,000 10,000 5,000 0 Afforestation rates Age distribution of forest estate Total State Private 1929 1933 1937 1941 1945 1949 1953 1957 1961 1965 1969 1973 1977 1981 1985 1989 1993 1997 2001 2005 2009 1925 1921 Annual afforestation (ha)
Dependant on afforestation rate Hendrick & Black, 2009
Conclusions Mitigation forests contributing significantly Age distribution a challenge Adaptation required Anticipatory policy strategies Modelling of outcomes/senarios and climate change Sustainable development across the industry (production and use of forest bio products)
Acknowledgments COFORD Coillte & private forest owners CARBiFOR project team
Thanks for your attention!