Land use and climate change in the UK

This paper reviews the relationships between land use and climate change. It explores how land use decisions will be affected by future changes in the climate, but also the feedbacks from land use change to the global climate system through greenhouse gas (GHG) fluxes. Past changes in land use were characterised by decreasing areas of agricultural use and increasing areas of forested and urbanised land. This has led to UK land use being a net sink for GHGs, mostly due to forestation. However, existing forests have on average passed their age for maximum net removals of carbon from the atmosphere. In the next decade at least, net removals from UK forests are likely to decrease significantly.Longer term scenarios of future land use change are consistent in their expectation of further declines in the agricultural area used for food production – offset to some extent by increased bioenergy cropping – along with increases in forested and urban areas. These trends are broadly consistent with the observed past land use change, but are calculated from various assumptions about future changes in drivers rather than by extrapolation from the past. Socio-economic and technological changes are likely to be the most important drivers for land use, with climate change having a smaller influence. The land use changes represented in these scenarios would likely reduce GHG emissions and enhance carbon sinks. These trends would be reinforced by small future changes in the climate, but large climatic changes are likely to cause net GHG fluxes to switch from being a sink to a source. Land use change will also be moderated by potential policy goals that seek to reduce GHG emissions from land and/or increase the size of land-based sinks. This includes strategies to reduce carbon and nitrogen emissions through increased efficiency, afforestation and biofuel production.     

The Need for Comprehensive Climate Change Mitigation Policies in European Agriculture

During the last decade the European Union has shown a firm determination to move to a low carbon economy. Since 2008 the agricultural sector has been part of this strategy and is included in the EU effort sharing decision. Introducing specific GHG mitigation obligations for agriculture could be one option to achieve an overall GHG emission reduction target. One argument for this strategy would be that the agricultural sector is the main contributor of non‐CO₂ greenhouse gases. Nevertheless, a comprehensive EU mitigation policy would most likely have to take into account the particularities of its diverse agricultural sector, reflected by different trends in historical GHG emission reductions, and a varied mitigation cost structure between farming systems. Consequently, using targeted but flexible policy instruments may more equitably distribute the mitigation efforts across Member States and reduce cost inefficiencies. The increased uptake of technological and management emission mitigation measures would be crucial to keep mitigation costs for EU farmers at a minimum. However, while unilateral action would initially signal the EU's commitment to serious GHG mitigation effort in the sector, ultimately a multilateral agreement is needed to minimise emission leakage and to reduce global GHG emissions effectively.     

Carbon offsets and agriculture: Options,obstacles, and opinions

While carbon offsets in agriculture can play a role in addressing climate change, they are not a perfect substitute for direct emission reductions. As shown in this paper through various arguments and case studies, climate policies in Canada have avoided the use of offsets to be sold in carbon markets, preferring instead to incentivize adoption of best management practices (BMPs) that provide environmental benefits along with climate mitigation benefits. We argue that this is a preferred policy option due to the perils and pitfalls inherent in the measurement and monitoring required to identify offset credits. While an appropriate approach might be to penalize Canadian farmers for any emissions their activities cause, this may do more harm than good. Canadian agricultural production is highly efficient and technologically advanced; therefore, reductions in Canada's contribution to the global food supply will result in less-efficient production occurring elsewhere (i.e., leakage) that increases global greenhouse gas emissions.     

Setting Climate Action as the Priority for the Common Agricultural Policy: A Simulation Experiment

We quantitatively assess the impacts of re-allocating budgetary resources within Pillar 1 of the EU's Common Agricultural Policy (CAP) from direct income support to a direct greenhouse gas (GHG) reduction subsidy for EU farmers. The analysis is motivated by the discussion on the future CAP, with calls for both an increased ambition on climate action from the agricultural sector and for a more incentive-based delivery system of direct payments under strict budgetary restrictions. By conducting a simulation experiment with an agricultural partial equilibrium model (CAPRI), we are able to factor in farmers’ supply and technology-adjusting responses to the policy change and to estimate the potential uptake of the GHG-reduction subsidy in EU regions. We find that a budget-neutral re-allocation of financial resources towards subsidised emission savings can reduce EU agricultural non-CO₂ emissions by 21% by 2030, compared to a business-as-usual baseline. Two-thirds of the emission savings are due to changes in production levels and composition, implying that a significant part of the achieved GHG reduction is offset globally by emission leakage. At the aggregated level, the emission-saving subsidy and increased producer prices compensate farmers for the foregone direct income support, but differences in regional impacts indicate accelerated structural change and heterogeneous income effects in the farm population. We conclude that the assumed regional budget-neutrality condition introduces inefficiencies in the incentive system, and the full potential of the EU farming sector for GHG emissions reduction is not reached, leaving ample room for the design of more efficient agricultural policies for climate action.     

Mitigation potential and costs for global agricultural greenhouse gas emissions1

Agricultural activities are a substantial contributor to global greenhouse gas (GHG) emissions, accounting for about 58% of the world's anthropogenic non‐carbon dioxide GHG emissions and 14% of all anthropogenic GHG emissions, and agriculture is often viewed as a potential source of relatively low‐cost emissions reductions. We estimate the costs of GHG mitigation for 36 world agricultural regions for the 2000–2020 period, taking into account net GHG reductions, yield effects, livestock productivity effects, commodity prices, labor requirements, and capital costs where appropriate. For croplands and rice cultivation, we use biophysical, process‐based models (DAYCENT and DNDC) to capture the net GHG and yield effects of baseline and mitigation scenarios for different world regions. For the livestock sector, we use information from the literature on key mitigation options and apply the mitigation options to emission baselines compiled by EPA.     

Quantifying the impact of farmers' social networks on the effectiveness of climate change mitigation policies in agriculture

To reduce agricultural greenhouse gas (GHG) emissions, farmers need to change current farming practices. However, farmers' climate change mitigation behaviour and particularly the role of social and individual characteristics remains poorly understood. Using an agent-based modelling approach, we investigate how knowledge exchange within farmers' social networks affects the adoption of mitigation measures and the effectiveness of a payment per ton of GHG emissions abated. Our simulations are based on census, survey and interview data for 49 Swiss dairy and cattle farms to simulate the effect of social networks on overall GHG reduction and marginal abatement costs. We find that considering social networks increases overall reduction of GHG emissions by 45% at a given payment of 120 Swiss Francs (CHF) per ton of reduced GHG emissions. The per ton payment would have to increase by 380 CHF (i.e., 500 CHF/tCO₂eq) to reach the same overall GHG reduction level without any social network effects. Moreover, marginal abatement costs for emissions are lower when farmers exchange relevant knowledge through social networks. The effectiveness of policy incentives aiming at agricultural climate change mitigation can hence be improved by simultaneously supporting knowledge exchange and opportunities of social learning in farming communities.     

Reducing greenhouse gas emissions from agriculture: Avoiding trivial solutions to a global problem

Three steps are required to successfully and efficiently reduce greenhouse gas (GHG) emissions from agriculture: (i) identification of the most GHG polluting farms, (ii) determining appropriate mitigation options for these farms, and (iii) selection between these options on the basis of their cost effectiveness. Carbon footprints of a sample of farms together with an analysis of the Kyoto Protocol show the difficulties encountered at each step. These difficulties are caused by: (i) failure to agree which functional unit to use to measure GHG emissions and pollution swapping; (ii) weaknesses in the Kyoto Protocol's territorial/production based accounting methodology, and (iii) lack of cost-effectiveness data. One consequence is that farmers may adopt mitigation activities that reduce their farm's, the UK agriculture sector's and the UK's emissions whilst inadvertently increasing global emissions: a trivial solution because it fails to address GHG emissions as a global problem. These difficulties, together with estimated agriculture sector marginal abatement cost curves that suggests emission reduction from all cost effective mitigation activities will not deliver targeted GHG emission reductions, means policy focus must be on demand rather than supply-side measures: the benefits and disadvantages of cap and trade mechanisms and carbon taxes are briefly discussed within an agricultural context.     

Logs or permits? Forestry land use decisions in an emissions trading scheme

Negative carbon emissions options are required to meet long-term climate goals in many countries. One way to incentivise these options is by paying farmers for carbon sequestered by forests through an emissions trading scheme (ETS). New Zealand has a comprehensive ETS, which includes incentives for farmers to plant permanent exotic forests. This research uses an economy-wide model, a forestry model and land use change functions to measure the expected proportion of farmers with trees at harvesting age that will change land use from production to permanent forests in New Zealand from 2014 to 2050. We also estimate the impacts on carbon sequestration, the carbon price, gross emissions, GDP and welfare. When there is forestry land use change, the results indicate that the responsiveness of land owners to the carbon price has a measured impact on carbon sequestration. For example, under the fastest land use change scenario, carbon sequestration reaches 29.93 Mt CO₂e by 2050 compared to 23.41 Mt CO₂e in the no land use change scenario (a 28% increase). Even under the slowest land use change scenario, carbon sequestration is 25.89 Mt CO₂e by 2050 (an 11% increase compared with no land use change). This is because, if foresters decide not to switch to permanent forests in 1 year, carbon prices and ultimately incentives to convert to permanent forests will be higher in future years.     

Bioelectricity in Malaysia: economic feasibility,environmental and deforestation implications

We investigate the economic feasibility of bioelectricity production from biomass in Malaysia and its impact on greenhouse gas (GHG) emissions and storage, agricultural prices, agricultural employment and deforestation. For this purpose, we develop a partial equilibrium model that projects agricultural prices, production, imports, exports, domestic consumption and land use in 5‐year increments between 2015 and 2065. Our results show that by 2030 biomass‐generated electricity can supply 36.5 per cent of the electricity generated in Malaysia, 16 times more than the 2016 electricity supply from biomass. Increased bioelectricity production from biomass will significantly reduce GHG emissions and will help Malaysia meet its commitment in the Paris Agreement to mitigate GHG emission by 45 per cent before 2030. Our modelling shows that biomass‐generated electricity creates a derived demand for waste biomass that expands the area of oil palm plantations. The expansion lowers agricultural prices, boosts agricultural employment and leads to some deforestation as landowners clear rainforest to plant oil palm trees. Nonetheless, the deforestation does not increase GHG emissions since GHG gains from bioelectricity significantly exceed GHG losses from deforestation.     

Information about Climate Change Mitigation: What Do Farmers Think?

The adoption of new practices by farmers is one of the key strategies to lower greenhouse gas (GHG) emissions from food production. In this context, effective knowledge transfer systems are essential to inform farmers about climate change, and to convince them of the benefits of new technologies. In this article, farmers’ opinions about climate change, their own efforts to mitigate climate change, and their suggestions on how to improve agricultural advice were assessed. To this end, a survey with over 500 livestock farmers was conducted in Ireland. The findings reveal a high awareness of the urgency to address climate change in general, but many farmers also think agricultural GHG emissions are an overstated problem. In addition, half of the surveyed farmers believe that implementing GHG mitigation measures will lower their profits. These findings underline the need to provide effective knowledge transfer to facilitate the uptake of GHG mitigation measures. When asking farmers directly, by way of text analysis, it emerges that simple messages, group and practical advice that is tailored to individual farming situations is important to farmers. As such, this article provides important insights that are of relevance for designing advisory campaigns to promote climate change mitigation.     

A detailed greenhouse gas budget for palm oil production

We have evaluated the global warming impact of palm oil production in a model that simulates the operations of a typical palm oil mill that processes fruit from a nucleus estate and outgrowers. It estimates carbon sequestration in the crop and in mill products and by-products, and balances this against the major sources of greenhouse gases (GHGs), all converted to carbon dioxide equivalents (CO₂-e) over the 25-year lifespan of the crop. The model shows that most carbon sequestration occurs in the standing crop, with smaller amounts in mill products and by-products. Land-use conversion plays a dominant role in the GHG budget, with planting of oil palm after logged forest or rubber leading to a net loss of carbon, and to a net gain following grassland. In the default oil-palm-to-oil-palm case the carbon lost from cleared palms is balanced by sequestration in the current crop. Methane from mill effluent and nitrous oxide from N fertilizers are the next most important emission sources. The default replant case gives net emissions of 0.86t CO₂-e per t crude palm oil, but these can be reduced to very low values, mainly through conversion of methane and surplus fuel in the mill to energy.     

Smallholder farms’ adaptation to the impacts of climate change: Evidence from China’s Loess Plateau

The impacts of climate change on agriculture in developing countries will depend on the extent to which agricultural production in those regions adapts to climate change’s influences. This study uses a whole-farm land use optimisation approach to explore climate change impacts, when including adaptation, on farm profitability, production and associated greenhouse gas (GHG) emissions in the Loess Plateau of northern China. The results show that with adaptation activities, the losses in smallholder farm profitability caused by the climate change could be moderate. Declining rainfall results in land use changes that generate higher on-farm GHG emissions with the most economically beneficial adaptations. With 5 % or 10 % decline in annual rainfall, the introduction of agricultural carbon tax would generate substantial reduction in on-farm GHG emissions. With 30 % rainfall reduction, agricultural carbon tax is not likely to bring about considerable emission reduction. The economically optimised land uses are generally sensitive to potential changes. When rainfall reductions appear, there is a clear trend toward reducing cropping area and transiting to pasture. With 5–10% rainfall reductions, increasing agricultural carbon tax with same rainfall reduction leads to the expansion in cropping enterprises. However, with 30 % rainfall reduction, land allocations are not sensitive to agricultural carbon tax. When with declining annual rainfall, in the optimal enterprises more oats-pasture rotations are employed to reduce wheat dominated rotations. Besides land use patterns, adaptations through altering farm management practices are also necessary. The economically optimised sheep flock would be increased considerably with declining rainfall. Overall, policymakers are suggested to initial more educational schemes to tell smallholder farmers how to make the best use of available adaptation strategies and consider changes in climate when design and implement agricultural policy.     

Does carbon farming provide a cost‐effective option to mitigate GHG emissions? Evidence from China

In this study, we apply a whole farm bioeconomic analysis to explore the changes in land use, farm practices and on‐farm greenhouse gas (GHG) emission under varying levels of agricultural greenhouse gas abatement incentives in the form of a carbon tax for a semi‐arid crop‐livestock farming system in China's Loess Plateau. Our results show that the optimised agricultural enterprises move towards being cropping‐dominated reducing on‐farm emission since livestock perform is the major source of emission. Farmers employ less oats‐based and rapeseed‐based rotations but more dry pea‐based rotations in the optimal enterprise mix. A substantial reduction in on‐farm greenhouse gas emission can be achieved at low cost with a small increase in carbon incentives. Our estimates indicate that crop‐livestock farmers in China's Loess Plateau may reduce their on‐farm GHG emission between 16.6 and 33 per cent with marginal abatement costs <￥100/t CO₂e and ￥150/t CO₂e in 2015 Chinese Yuan. The analysis implies that reducing greenhouse gas emission in China's semi‐arid crop‐livestock agriculture is potentially a low‐cost option.     

Net Greenhouse Gas Emissions and the Economics of Annual Crop Management Systems

The aim of this study was to evaluate the relative economic profitability and net greenhouse gas (GHG) abatement potential of alternative tillage and cropping systems. A simulation model was parameterized using biophysical and economic data representing different crop rotations under conventional, minimum, and zero tillage cropping systems, in the Black soil zone of Saskatchewan. This model was used to estimate the relative potential of each of the management practices to sequester carbon and to emit GHG including, nitrous oxide and carbon dioxide. The model also provided estimates of the relative profitability of each of the management practices over time horizons of 30 years. These simulation results were used to develop trade-off functions reflecting net income and net GHG abatement for each cropping system. An income risk measure was incorporated to facilitate an analysis of the relative economic attractiveness of the simulated cropping systems. Furthermore, sensitivity analysis was performed on nitrous oxide emission coefficients (an area of significant uncertainty in the literature) and on weather patterns to reflect uncertain future climate change impacts. Results indicated that net GHG emissions were relatively lower for reduced tillage management, while conventional tillage may be relatively more attractive from an economic perspective. However, results also indicated that such economic factors as risk and economies of size may have a significant influence on this latter result.     

农户农业碳排放效率差异及多层次影响因素——以陕西省米脂县为例

目的 分析农户尺度农业碳排放效率差异并揭示多层次影响因素,对提供微观决策支持和推进农业农村低碳高效发展意义重大。方法 文章以陕西省米脂县为例,在测算57个村庄共861个农户农业碳排放及效率的基础上,从农户尺度分析农业碳排放及效率差异,最后基于多层次模型揭示其影响因素。结果 （1）农户整体农业碳排放效率较低,且示范村中的农户农业碳排放效率高于非示范村农户,示范村与非示范村下同一类型农户的冗余类型及占比和示范村（或非示范村）不同类型农户的冗余类型及占比差异明显;（2） 年龄、务农年限、教育水平和农业技能培训是影响农户农业碳排放量的主要因素。（3）就全体农户而言,乡村振兴示范村、距县城距离和政府支持力度是影响农户农业碳排放效率的主要环境变量,务农年限和受教育水平是影响农户农业碳排放效率的主要个体变量。影响示范村与非示范村农户农业碳排放效率的因素有较大差异。结论 不同类型农户农业碳排放效率和影响因素迥异,应根据村庄环境、农户特征等进行差异化政策支持。     

Achieving successful farmer engagement on greenhouse gas emission mitigation

This paper explores the potential for farmers’ engagement on the issues related to greenhouse gas (GHG) emission mitigation in extensive low-input livestock farming systems. The framework used was based on Participatory Action Research. This involved integrating quantitative evidence on GHG emission impacts at the farm level and qualitative data on the obstacles to the adoption of innovation based on farmers’ perceptions and attitudes to climate change. The study aims at building social capital among 14 farmers in the South West and West Midlands regions in England, and it evaluates the potential for the adoption of emission mitigation strategies. The Rapid Farm Practices Appraisal (RFPA) tool was created to assess farm practices based on their mitigation potential. Practices were assessed twice over 6–9 months. Semi-structured interviews were used to assess barriers and opportunities to farmer engagement and on-farm innovation. Farmers were invited to a focus group meeting to network with other farmers and engage with researchers. All farmers participated in the 2 farm assessments, but only half the farmers adopted changes in farm management. All farmers appreciated the RFPA tool, the clearness of the information provided and the focus of the tool on practices directly. The main obstacles to innovation were limited financial capital, lack of trust in government action and confusion over the effectiveness of farm advice on mitigation. The lack of long-term flexibility of agricultural policies and the source of information greatly influenced the acceptance of advice. Results suggest the potential for the expansion of the RFPA tool to include economic assessment of farm practices and the engagement of a larger pool of farmers and farming systems. The tool could be used to support the GHG Action Plan and future environmental policies, and as an integrated self-assessment tool for farmers under Environmental Stewardship Schemes.     

Non‐Parametric Modelling of CO2 Emission Quota

Dutch glasshouse firms are facing the introduction of a system of tradable CO₂ emission quotas. This paper employs a non‐parametric method for modelling tradable CO₂ emissions of Dutch glasshouse firms. The method is capable of generating shifts in CO₂ emissions across the sample of firms. Moreover, changes in volumes of outputs produced and inputs used are computed. Results show that firms using a conventional heating technology will be net purchasers of CO₂ emissions, whereas firms using more advanced heating technologies will sell part of their emission quota.     

Sequester or substitute—Consequences of increased production of wood based energy on the carbon balance in Finland

Forests play an important role in mitigating climate change. Forests can sequester carbon from the atmosphere and provide biomass, which can be used to substitute for fossil fuels or energy-intensive materials. International climate policies favor the use of wood to substitute for fossil fuels rather than using forests as carbon sink. We examine the trade off between sequestering carbon in forests and substituting wood for fossil fuels in Finland. For Finland to meet its EU targets for the use of renewable energy by 2020, a considerable increase in the use of wood for energy is necessary. We compare scenarios in which the wood energy targets are fully or partially met to a reference case where policies favoring wood based energy production are removed. Three models are used to project fossil fuel substitution and changes in forest carbon sinks in the scenarios through 2035.Finnish forests are a growing carbon sink in all scenarios. However, net greenhouse gas (GHG) emissions will be higher in the medium term if Finland achieves its current wood energy targets than if the use of energy wood stagnates or decreases. The volume of GHG emissions avoided by replacing coal, peat and fossil diesel with wood is outweighed by the loss in carbon sequestered in forests due to increased biomass removals. Therefore, the current wood energy targets seem excessive and harmful to the climate. In particular, biodiesel production has a significant, negative impact on net emissions in the period considered. However, we did not consider risks such as forest fires, wind damage and diseases, which might weaken the sequestration policy. The potential albedo impacts of harvesting the forests were not considered either.     

Marginal Abatement Cost Curves for UK Agricultural Greenhouse Gas Emissions

This article addresses the challenge of developing a ‘bottom‐up’ marginal abatement cost curve (MACC) for greenhouse gas (GHG) emissions from UK agriculture. An MACC illustrates the costs of specific crop, soil and livestock abatement measures against a ‘business as usual’ scenario. The results indicate that in 2022 under a specific policy scenario, around 5.38 Mt CO₂ equivalent (e) could be abated at negative or zero cost. A further 17% of agricultural GHG emissions (7.85 Mt CO₂e) could be abated at a lower unit cost than the UK Government’s 2022 shadow price of carbon [£34 (tCO₂e)^?1]. The article discusses a range of methodological hurdles that complicate cost‐effectiveness appraisal of abatement in agriculture relative to other sectors.     

The influence of crediting and permanence periods on Australian forest-based carbon offset supply

Governments globally are developing increasingly ambitious carbon emissions reduction schemes that include significant emissions offset credits for forest-based carbon sequestration. Such strategies can present significant challenges in highly modified and intensively farmed regions where forest land use opportunity and establishment costs are high. This article evaluates the economics of land-use change via active afforestation for local carbon abatement in the Australian state of South Australia, a region with high supply costs representative of long-established temperate farming regions. We found that there is no economically viable abatement below $38 tCO₂e⁻¹, however up to 154 Mt CO₂e of abatement could be available up to prices of $50 tCO₂e⁻¹.Variation in current Australian Emissions Reduction Fund (ERF) policy parameters related to permanence and crediting periods were also assessed. Recent ERF contracts involve a 100-year land-use change commitment (permanence period) and a 25-year crediting period where payments for growth in carbon from the land-use change is contracted. We compared outcomes of this arrangement to a scenario with equal 100-year permanence and crediting periods. We found substantial differences in carbon supply at some price points for a 25 rather than a 100-year crediting period. Under ERF parameters the first economically viable revegetation options occur at $42 tCO₂e⁻¹, however, we found a 69 percent reduction in economically viable supply at a carbon price of $50 tCO₂e⁻¹. The results highlight the role offset crediting policy can have on dis-incentivising land-use change and the need for landholders to be compensated fully for temporal opportunity costs.