Policy options to achieve the 80% cut Land Management, Sequestration and Sinks Robin Matthews Climate Change Theme Leader Macaulay Institute Aberdeen AB15 8QH Presentation at Scottish Parliament, November 19, 2008

Structure of the talk 1.Background 2.Contribution to overall Scottish GHG emissions made by the land use sector 3.Trends in GHG emissions from the land use sector 4.Scope for the use of land for sequestration and sinks

Emissions from the land use sector However, Scotlands soils contain: –Shallow organic soils: ~1400 Mt C –Peat soils: Mt C Forests and soils have considerable capacity to store carbon N 2 O: N-fertiliser, wet acid soils, animals CH 4 : livestock, natural peat bogs CO 2 : cultivation, fuel consumption

Carbon sequestration

Effect of land use change on soil C New Zealand average 0.33 t C ha -1 y t C ha -1 y -1 in first 3 years Geescroft Wilderness: converted from arable to woodland in 1880s

Scale of the contribution 62% of UKs removals is by Scottish forests (2003) From Changing Our Ways: Scotlands Climate Change Programme, SEERAD, Scotlands total emissions: 59 Mt CO 2 e yr -1 Land use emissions: 11.8 Mt CO 2 e yr -1

Trends in main GHG source/sinks ForestryLivestock Land use changeN fertiliser application

LULUCF source/sink trends From AEA (2008), Greenhouse Gas Inventories for England, Scotland, Wales & Northern Ireland: Scotland decline in cattle and sheep numbers increase in sink size by 78% 60% reduction

Agricultural management alternative carbon-neutral energy crops increased C sequestration through different ground covers and land management reducing CH 4 emissions from livestock more efficient use of organic and inorganic fertilisers Initial calculations suggest abatement potential of 1.57 MtCO 2 e

Land use change: arable to grassland Scotland: 600,250 ha

Land use change: arable to grassland 600,250 ha of cropland in Scotland Assume all is converted into grassland Sequestration rate: ~1.5 t CO 2 ha -1 y -1 Abatement potentials: –setaside: 0.97 MtCO 2 e y -1 –beef: 0.11 MtCO 2 e y -1 –sheep: 0.40 MtCO 2 e y -1 –dairy: MtCO 2 e y -1 Abatement potential Ignoring land suitability for the moment

Land use change: forestry Options afforestation of abandoned agricultural lands forest management to increase carbon density at the stand/landscape level –maintaining forest cover –minimising soil C loss –increasing rotation lengths –increasing growth –managing drainage increasing off-site carbon stocks in wood products enhancing product and fuel substitution

Land use change: forestry Current forest area: 1,347,001 ha 2050 target: 1,969,300 ha (+622,299 ha) Assume sequestration rate is 11 t CO 2 ha -1 yr -1 Abatement potential: 6.8 Mt CO 2 e yr -1 (12.5%) Changing Our Ways (2006): The forestry sector should deliver annual carbon savings of –2.2 Mt CO 2 e by 2010 (4.0%) –2.9 Mt CO 2 e by 2015 (5.4%) –3.7 Mt CO 2 e by 2020 (6.7%) Forestry Strategy: Increase of forestry from 17-25%

Forest planting rates

Tradeoffs for landuse As climates warm, more marginal areas will become suitable for agriculture What will be the implications for: –food production –bioenergy –timber –water quality, quantity –soils –carbon storage –biodiversity

Land use change: peat restoration total peat area: 1,096,000 ha degraded basin peat: ~24,000 ha eroded blanket peat: ~9,000 ha functioning peat-bog sequesters ~730 kg CO 2 ha -1 y -1 degraded bog could lose ~730 kg CO 2 ha -1 y -1 one-off cost of £ per ha abatement potential: 1460 × 33,000 × = Mt CO 2 e y % of Scotlands emissions of 55 Mt CO 2 yr -1

Summary Abatement potential Fraction of AFOLU Fraction of total (MtCO 2 e yr -1 )(%) Agriculture Cropland to grassland Forestry Peatland TOTAL Proviso: Very ballpark figures – indicative only! Many assumptions that need to be tested More detailed UK study to be published by Office of Climate Change in December

Marginal abatement cost curves Options ranked in decreasing order of cost-effectiveness Width of each bar (x-axis): abatement potential (AP) Height of each bar (y-axis): cost- effectiveness (CE) Comparing the abatement scenario with a baseline Cheap option, big emission savings Expensive options, small emission savings Financial savings