QUEST: Quantifying and Understanding the Earth System
Major themes | Theme 3 | QUATERMASS
QUATERMASS: Quantifying the potential of terrestrial biomass to mitigate climate change.
Leader: Dr Jeremy Woods (Imperial College London)
Mitigating climate change through land-use change
Arkhangelsk region of Northwest Russia, the site of two biosphere management projects for climate change mitigation on ‘Forest Conservation’ and ‘Improved Forest Management’. Photo courtesy of Daria Lugovaya at WWF, Russia.
The QUATERMASS project used scientific analyses of carbon uptake and release by forestry, biofuels and other land-use changes to investigate climate change mitigation options. It used innovative new approaches to land-use evaluation, and integrated forestry and agroeconomic modelling (of agricultural, forestry and bioenergy production with global trade) to create a scientific framework for policy. It will analyse the environmental and socio-economic impacts of mitigation options and trade-offs of ecosystem services by country and region.
Key questions the QUATERMASS project addressedk:
- What is the maximum amount of carbon that can be stored in the terrestrial biosphere without causing unacceptable consequences for water supply, food production, fibre production, trade, bioenergy and biodiversity?
- What kinds of socio-economic and institutional constraints limit storage of carbon in the biosphere?
- How does using land-use policy for climate change mitigation affect different geographical regions?
- What range of land-use policies are needed to contribute to effective global mitigation and satisfy the diversity of regional constraints?
Approach
A 4 year plantation of indigenous poplar in the
Small Islands of Braila, Romania, 2007, for a JI project
on "Afforestation of Degraded Agricultural Land".
Photo courtesy of Viorel Blujdea at ICAS Bucuresti,
Romania.
Plants take carbon from the atmosphere and store it in their biomass and in soils. Thus land-use and land management are important tools in climate change mitigation. Furthermore, plant biomass can be used as a bioenergy source, offsetting the use of fossil fuels and reducing carbon emissions. Avoiding deforestation, increasing plant storage through afforestation or plant management, and substituting bioenergy for fossil fuels all use the land resource base to reduce climate change. Policy makers are currently making decisions, negotiating targets, and agreeing accounting methodologies and rules based around these options. Yet these options are not without their costs and impacts on other sectors. In order for sound decision making there is a need for integrated scientific information comparing different options, opportunities and consequences.
Carbon sequestration through land use is a complex process. Land-use change affects many physical and socioeconomic systems including: food production, timber production, bioenergy, economics, rainfall feedbacks, potable water processing, preservation of habitats and biodiversity. Interactions between them can produce unintended consequences. For example, under some scenarios EU biofuel targets are projected to cause increasing deforestation by increasing demand for crop land, undermining the primary GHG emissions reduction intention of the policy. For example, Figure 1 shows deforestation in different regions in millions of hectares due to EU biofuel expansion.
Figure 1 Deforestation due to EU biofuel expansion in millions of hectares against percentage of 2020 liquid biofuel projection for Latin America/Caribbean (dark green triangles 2-4.5Mha), Pacific Asia (black triangles 0-1.0 Mha) and Sub Saharan Africa (light green triangles 0-1 Mha).
Therefore an integrated approach to policy development is needed. Our research takes account of :
- direct and indirect GHG emissions from biofuels over the whole growth/trade lifecycle;
- global land cover types and the ecosystem services they provide;
- land-use modelling including agricultural and economic feedbacks (IIASA);
- land use change policies that are scientifically feasible within the next ten years, and their consequences for 2030s, 2050s and 2100.
to enable policymakers to compare and balance mitigation options, and understand their consequences for production of food, fibre, chemicals and energy in the short and long term. The evidence of local case studies in China (afforestation on sloping lands), the Amazon (avoided deforestation), Ethiopia (avoided deforestation of Bali mountain), NW Russia (forest conservation) will be used to test the robustness and some of the institutional issues of the optimized mitigation policy options.
About National Biomass Resource Assessment
Photo courtesy of Daria Lugovaya.
To complement the agroeconomic modelling information (IIASA), this project tackles the challenge of taking account of land-use types and their potential, using an ecosystem services approach. This explicitly avoids the assumption that any land is “available” at no cost as it accepts that all land is of value in some way, and decisions on changing land use must take account of many factors. The opportunity costs (economic, environmental and social) for changes in land use will be assessed. This National Biomass Resource Assessment will use current maps and statistics of land cover and land use to assess what land is under different uses, country by country. Soil types and forest litter are simulated and the services provided by these land areas considered. Conversion factors will be used to translate the land-use potential into options for greenhouse gas offsets and energy production. These are combined to create a simulation of the national estate. It will then look at implementing different options on different land use classes.
The conversion factors enable comparison of the benefits and productivity of the land use types, as depicted in Figure 2.
Figure 2 Schematic diagram of relationship between the benefits and productivity of land use types.
An optimized policy framework
The agroeconomic modelling allows us to tune the model system to find the limits of policy, such as the minimum greenhouse gas emissions or maximum food productivity. We can also set global targets for agroeconomic parameters, such as GHG emissions, and find out what the optimal theoretical global land-use policy would be. The consequences for GHG emissions and trade of setting a particular land-use scenario can also be described.
Our research is framing the limits of biomass mitigation to enable policymakers to decide how to balance needs such as
- avoided deforestation vs. bioenergy plantations,
- sequestration (afforestation) vs. substitution (bioenergy),
- protecting peatlands vs. bioenergy,
- relative outcomes of different bioenergy conversion pathways
Indicative forestry analysis results
The National Biomass Resource Assessment is being applied to countries with a wide-range of climate change mitigation policy issues. Indicative results for the UK are shown below in Figure 3. For this country, the net affect of aforestation and improved forest management techniques increases the carbon sink to 2030, relative to business-as-usual. Longer-term projections are also needed to take account of multi-decadal tree-felling cycles.
Figure 3 Relative carbon source/sink in megatonnes of carbon per year from 1990 to 2030 simulated/projected by the National Biomass Resources Assessment using scenarios implemented in 2010: A - Aforestation, FM - Forest Management, and NET - their net effect. Positive values represent carbon sinks.
Project partners: Imperial College's Bioenergy Group, Forest Research, Aberdeen University, Ecometrica, International Institute for Applied Systems Analysis (IIASA), and the University of Bristol/QUEST.
Further information available from:
Robert Matthews, QUATERMASS Scientist robert.matthews@forestry.gsi.gov.uk
or Fiona Hewer, QUEST Policy Liaison Officer, fiona@fionasredkite.co.uk.
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