Agricultural soil carbon accumulation in North America: considerations for climate policy

The Kyoto Protocol introduces the possibility that changes in carbon stock on agricultural and forest land and soils may be counted against countries’ commitments to reduce their greenhouse gas emissions. Including activities related to land use change and forestry in the international climate change agreement may stimulate new incentives for soil-conservation practices domestically. However, a primary criteria for their inclusion relates to the level of accuracy and transparency with which carbon stock changes can be assessed. Parties will also be concerned with the wider environmental impact of different sequestration practices, and the impact of offsets on overall emissions targets. This paper examines these issues for agricultural soils, considering recent research in North America. It is argued that incentives for carbon sequestration practices may need to be implemented independently of actual stock changes because farm-level soil monitoring would be very costly. In the USA, priority should be given to establishing incentives for cover crops and to expanding conservation tillage programs. These activities provide a range of ancillary environmental benefits. In contrast, improvements in biomass yield tend to rely on higher fertilizer inputs with their related environmental costs. Carbon accumulated through any of these activities is easily lost if the practices are discontinued, and so assessment procedures are needed that would avoid overestimating sequestration. Annual accumulation in agricultural soils could be equivalent to about 10% of Annex I carbon dioxide emissions, and therefore options for limiting sink credits from soils should be considered.     

Building SSPs for climate policy analysis: a scenario elicitation methodology to map the space of possible future challenges to mitigation and adaptation

The scientific community is now developing a new set of scenarios, referred to as Shared Socio-economic Pathways (SSPs) that will be contrasted along two axes: challenges to mitigation, and challenges to adaptation. This paper proposes a methodology to develop SSPs with a “backwards” approach based on (i) an a priori identification of potential drivers of mitigation and adaptation challenges; (ii) a modelling exercise to transform these drivers into a large set of scenarios; (iii) an a posteriori selection of a few SSPs among these scenarios using statistical cluster-finding algorithms. This backwards approach could help inform the development of SSPs to ensure the storylines focus on the driving forces most relevant to distinguishing between the SSPs. In this illustrative analysis, we find that energy sobriety, equity and convergence prove most important towards explaining future difference in challenges to adaptation and mitigation. The results also demonstrate the difficulty in finding explanatory drivers for a middle scenario (SSP2). We argue that methodologies such as that used here are useful for broad questions such as the definition of SSPs, and could also be applied to any specific decisions faced by decision-makers in the field of climate change.     

The benefits of climate change mitigation in integrated assessment models: the role of the carbon cycle and climate component

Integrated Assessment Models (IAMs) are an important tool to compare the costs and benefits of different climate policies. Recently, attention has been given to the effect of different discounting methods and damage estimates on the results of IAMs. One aspect to which little attention has been paid is how the representation of the climate system may affect the estimated benefits of mitigation action. In that respect, we analyse several well-known IAMs, including the newest versions of FUND, DICE and PAGE. Given the role of IAMs in integrating information from different disciplines, they should ideally represent both best estimates and the ranges of anticipated climate system and carbon cycle behaviour (as e.g. synthesised in the IPCC Assessment reports). We show that in the longer term, beyond 2100, most IAM parameterisations of the carbon cycle imply lower CO₂ concentrations compared to a model that captures IPCC AR4 knowledge more closely, e.g. the carbon-cycle climate model MAGICC6. With regard to the climate component, some IAMs lead to much lower benefits of mitigation than MAGICC6. The most important reason for the underestimation of the benefits of mitigation is the failure in capturing climate dynamics correctly, which implies this could be a potential development area to focus on.     

Global and regional ocean carbon uptake and climate change: sensitivity to a substantial mitigation scenario

Under future scenarios of business-as-usual emissions, the ocean storage of anthropogenic carbon is anticipated to decrease because of ocean chemistry constraints and positive feedbacks in the carbon-climate dynamics, whereas it is still unknown how the oceanic carbon cycle will respond to more substantial mitigation scenarios. To evaluate the natural system response to prescribed atmospheric ??target?? concentrations and assess the response of the ocean carbon pool to these values, 2 centennial projection simulations have been performed with an Earth System Model that includes a fully coupled carbon cycle, forced in one case with a mitigation scenario and the other with the SRES A1B scenario. End of century ocean uptake with the mitigation scenario is projected to return to the same magnitude of carbon fluxes as simulated in 1960 in the Pacific Ocean and to lower values in the Atlantic. With A1B, the major ocean basins are instead projected to decrease the capacity for carbon uptake globally as found with simpler carbon cycle models, while at the regional level the response is contrasting. The model indicates that the equatorial Pacific may increase the carbon uptake rates in both scenarios, owing to enhancement of the biological carbon pump evidenced by an increase in Net Community Production (NCP) following changes in the subsurface equatorial circulation and enhanced iron availability from extratropical regions. NCP is a proxy of the bulk organic carbon made available to the higher trophic levels and potentially exportable from the surface layers. The model results indicate that, besides the localized increase in the equatorial Pacific, the NCP of lower trophic levels in the northern Pacific and Atlantic oceans is projected to be halved with respect to the current climate under a substantial mitigation scenario at the end of the twenty-first century. It is thus suggested that changes due to cumulative carbon emissions up to present and the projected concentration pathways of aerosol in the next decades control the evolution of surface ocean biogeochemistry in the second half of this century more than the specific pathways of atmospheric CO₂ concentrations.     

Seeing the trees for the carbon: agroforestry for development and carbon mitigation

Land-use, land-use change and forestry (LULUCF) activities will play an important role in global climate change mitigation. Many carbon schemes require the delivery of both climate and rural development benefits by mitigation activities conducted in developing countries. Agroforestry is a LULUCF activity that is gaining attention because of its potential to deliver climate benefits as well as rural development benefits to smallholders. There is hope that agroforestry can deliver co-benefits for climate and development; however experience with early projects suggests co-benefits are difficult to achieve in practice. We review the literature on agroforestry, participatory rural development, tree-based carbon projects and co-benefit carbon projects to look at how recommended project characteristics align when trying to generate different types of benefits. We conclude that there is considerable tension inherent in designing co-benefit smallholder agroforestry projects. We suggest that designing projects to seek ancillary benefits rather than co-benefits may help to reduce this tension.     

Felt responsibility and climate engagement: Distinguishing adaptation from mitigation

Policy makers and citizens must choose from among a growing variety of strategic options as they try to cope optimally with climate change. As a means of more accurately predicting different types of climate change engagement, we empirically distinguish individuals’ felt responsibility for mitigation (FRm) from felt responsibility for adaptation (FRa), and assess support for different climate action strategies (mitigation and adaptation). We surveyed two U.S. samples two months apart, and the replication study confirmed Study 1′s findings of differing predictive powers for FRm vs. FRa. Each type of felt responsibility, controlling for the other, served as a mediator between belief in global warming (as well as belief in anthropogenic cause of climate change) and its corresponding climate action strategy (mitigation vs. adaptation). FRa predicted adaptation measures but not mitigation measures, while FRm predicted mitigation measures more strongly than it predicted adaptation but did predict both action strategies. We also found important individual differences: people’s disposition toward behaving proactively correlated positively with all types of climate engagement, and political orientation (liberal/conservative ideology) interacted with climate action strategy (mitigation vs. adaptation) in predicting all engagement variables. Comparing levels of support across the political spectrum, the mitigation measures were highly polarizing, while the adaptation measures were less divisive.     

Integrating agriculture and climate change mitigation at landscape scale: Implications from an Australian case study

Rural and regional hinterlands provide the ecosystem service needs for increasingly urbanised communities across the globe. These inter-related ecosystem services provide key opportunities in securing climate change mitigation and adaptation. Their integrated management in the face of climate change, however, can be confounded by fragmentation within the complex institutional arrangements concerned with natural resource management. This suggests the need for a more systemic approach to continuous improvement in the integrated and adaptive governance of natural resources.This paper explores the theoretical foundations for integrated natural resource management and reviews positive systemic improvements that have been emerging in the Australian context. In setting clear theoretical foundations, the paper explores both functional and structural aspects of natural resource governance systems. Functional considerations include issues of connectivity, knowledge use and capacity within the natural resource decision making environment. Structural considerations refer to the institutions and processes that undertake planning through to implementation, monitoring and evaluation.From this foundation, we review the last decade of emerging initiatives in governance regarding the integration of agriculture and forests across the entire Australian landscape. This includes the shift towards more devolved regional approaches to integrated natural resource management and recent progress towards the use of terrestrial carbon at landscape scale to assist in climate change mitigation and adaptation. These developments, however, have also been tempered by a significant raft of new landscape-scale regulations that have tended to be based on a more centralist philosophy that landowners should be providing ecosystem services for the wider public good without substantive reward.Given this background, we explore a case study of efforts taken to integrate the management of landscape-scale agro-ecological services in the Wet Tropics of tropical Queensland. This is being achieved primarily through the integration of regional natural resource management planning and the development of aggregated terrestrial carbon offset products at a whole of landscape scale via the Degree Celsius initiative. Finally, the paper teases out the barriers and opportunities being experienced, leading to discussion about the global implications for managing climate change, income generation and poverty reduction.     

Micro hydropower: an alternative for climate change mitigation,adaptation, and development of marginalized local communities in Hispaniola Island

In this essay, we explore the contribution of establishing off-grid community micro-hydropower systems in the Dominican Republic to climate change mitigation and adaptation. Forty-five micro-hydropower systems were set up over 16 years that are sustainably and autonomously managed by the local groups and provide access to electricity to communities in remote areas while reducing CO₂ emissions and favoring carbon sequestration. In addition to mitigating climate change by avoiding emissions and reforestation of more than 28,000 t of CO₂ per year, these initiatives have improved the adaptive capacity of the local communities through contributing to biodiversity protection, climate policy development, and governance; as well as enhancing the wellbeing of families through increased savings, improved education, and increased income generation opportunities. We elaborate the key factors for success and considerations for meeting future challenges.     

Developments in national climate change mitigation legislation and strategy

The results are presented from a survey of national legislation and strategies to mitigate climate change covering almost all United Nations member states between 2007 and 2012. This data set is distinguished from the existing literature in its breadth of coverage, its focus on national policies (rather than international pledges), and on the use of objective metrics rather than normative criteria. The focus of the data is limited to national climate legislation and strategies and does not cover subnational or sectoral measures. Climate legislation and strategies are important because they can: enhance incentives for climate mitigation; provide mechanisms for mainstreaming; and provide a focal point for actors. Three broad findings emerge. First, there has been a substantial increase in climate legislation and strategies between 2007 and 2012: 67% of global GHG emissions are now under national climate legislation or strategy compared to 45% in 2007. Second, there are substantial regional effects to the patterns, with most increases in non-Annex I countries, particularly in Asia and Latin America. Third, many more countries have adopted climate strategies than have adopted climate legislation between 2007 and 2012. The article concludes with recommendations for future research.

Policy relevance The increase in climate legislation and strategy is significant. This spread suggests that, at the national level, there is some movement in reshaping climate governance despite the relatively slow pace of global negotiations, although the exact implications of this spread require further research on stringency of actions and their implementation. Asia and Latin America represent the biggest improvements, while OECD countries, which start from a high base, remain relatively stagnant. Implications of regional patterns are further refined by an analysis by emissions, which shows that some areas of low levels of legislation and strategy are also areas of relatively low emissions. A broad trend toward an emphasis on strategies rather than legislation, with the significant exception of China, calls for enhanced research into the practical impact of national non-binding climate strategies versus binding legislation on countries’ actual emissions over time.     

能源补贴政策及其改革——为减排提供经济激励

The subsidy, as a measure, is widely applied by governments at all levels around the world as a way of policy interventions. However, there are two completely opposite opinions of subsidies on energy and environmental protection. The only reason for subsidy in existence is the internalization of external benefit. The paper firstly examines the energy subsidy policies relevant to climate change mitigation in China and their effectiveness, then points out the deficiency existing in energy conservation policies and renewable energy development policies, and finally suggests that China should exert positive role of subsidy policies and reduce negative effects in promoting climate change mitigation.     

Effects of climate change and elevated atmospheric CO2 on soil organic carbon: a response equation

Climate change, such as warming and precipitation change, as well as elevated CO₂ can affect soil organic carbon (SOC) dynamics and cause changes in soil carbon sequestration. In this study, we introduced a response equation, relating the relative change of SOC to the relative changes of annual average temperature, annual precipitation, and atmospheric CO₂ concentration, as well as their inter-products. Using Nelson Farm as a case study, based on simulations of CENTURY model and multiple regressions, we examined the response equation for three vegetation covers (i.e., soybean, corn, and grass) and scenarios with different soil erosion rates and initial SOC contents. The response equation fit the simulation results very well with high adjusted coefficients of determination (R ²) (0.982 to 0.990). The results showed that the SOC was negatively related to the annual average temperature, positively related to the annual precipitation, and positively related to the elevated CO₂ for all the vegetation covers (p?<?0.001). The SOC was also significantly impacted by the interaction effects between elevated CO₂ and warming or precipitation change (p?<?0.001). The general form of the response equations for the different vegetation covers, soil erosion rates, and initial SOC contents was the same although the parameters varied with the different conditions. Based on the response equation, ??cutoff surfaces?? were defined to clearly quantify the synthesis effects of any possible combination of climate change and elevated CO₂ on the SOC, and the SOC sequestration potential was assessed under climate change and elevated CO₂ for different vegetations. Compared with the empirical models in the literature, this response equation provides a simple yet but robust method to represent the relationship between the SOC relative change vs. the relative changes of atmospheric temperature, precipitation, and atmospheric CO₂ concentration.     

Energy-intensive manufacturing sectors in China: policy priorities for achieving climate mitigation and energy conservation targets

In this study, a long-range energy alternative planning (LEAP) model was built to evaluate the relative priority of three kinds of policies expected to be implemented for the energy-intensive manufacturing sectors (EIMS) in China to achieve CO₂ mitigation and energy conservation targets. These policies encourage (1) the use of more electricity instead of coal; (2) the continuous improvement of energy efficiency; and (3) a shift to other less energy-demanding sectors. The results indicate that the policy of shifting economic activity from the EIMS to other sectors is most helpful for China to achieve its targets of mitigating CO₂ emissions and conserving energy. Encouraging the EIMS to use more electricity can help China to achieve a higher proportion of non-fossil-fuel based energy in its overall primary energy consumption. No single policy will allow China to achieve all the targets, emphasizing the need for an integrated policy design that combines all types of policies.

Key policy insights

• The policy of encouraging a shift to less energy intensive industries should receive the highest priority in aiming to peak China's energy-related CO₂ emissions as early as possible, and lower overall CO₂ emissions, coal consumption and primary energy consumption in the long run.

• Encouraging a shift to electricity should go hand-in-hand with greater energy efficiency, otherwise such a policy cannot help China significantly reduce energy-related CO₂ emissions.

• Encouraging the EIMS to use more electricity should receive the highest priority in helping China achieve a higher proportion of non-fossil-fuel based energy in its overall primary energy consumption.

     

Four intermediate goals: a methodology for evaluation of climate mitigation policy packages

This study aimed to evaluate climate mitigation policy packages in various countries’ nationally determined contributions by introducing four intermediate policy goals: decarbonizing energy, improving energy efficiency, reducing demand for energy services, and enhancing carbon sinks and reducing emissions of non-CO₂ gases. The methodology was examined by using data of China, Germany, Japan, the UK, and the US. Climate mitigation policies introduced between 1990 and 2015 in the five countries were categorized into four intermediate policy goals. Six indicators were introduced to measure actual outcomes, each representing one of the four intermediate policy goals. A comparison between the policy categorizations and the indicator outputs led to the conclusion that the number of policies implemented partially reflects the countries’ efforts to achieve specific policy goals, even though the stringency of each policy was not taken into account. This comparison was also useful in identifying key policies that were effective in achieving policy goals, even if there was a relatively small number of policies. The methodology was useful in generating policy recommendations to fulfil all the four intermediate goals in a balanced manner.

POLICY RELEVANCE

The Paris Agreement, adopted at the 21st Conference of the Parties to the United Nations Framework Convention on Climate Change (COP21) in December 2015, calls for all countries to prepare, communicate, and maintain successive nationally determined contributions (NDCs) and pursue domestic mitigation measures with the aim of achieving the objectives of such contributions (Article 4.2). Under this new regime, methodologies to assess policy implementation have become increasingly important, especially for the post-2020 period. The methodology developed in this study is simple enough for any country to use and was effective in grasping the overall characteristics of the climate mitigation policy package in each country or region studied. The study recommends that the UNFCCC create a rule requesting countries to submit estimates of population, GDP, total energy demand, share of renewables, and other relevant factors for the target year when they submit their successive intended NDCs.     

西北地区退耕还林对区域气候的影响

利用区域气候模式RegCM3,研究我国西北地区退耕还林,对区域气候可能产生的影响。对比分析结果表明：大规模有组织的退耕还林会对中国局地和区域气候产生显著的影响,但不同的退耕方式会产生不同的气候效应。退耕还林会使我国的雨带北移,北方地区降水增加,南方地区降水减少。退耕还林可使我国夏季平均温度降低,冬季温度升高,并且随退耕区的扩大,幅度增大。     

Comparing public rationales for justice trade-offs in mitigation and adaptation climate policy dilemmas

Despite a great deal of research on public perceptions of climate change science, very little empirical work has attempted to investigate how members of the lay public might evaluate the justice dilemmas inherent within climate policy decision-making. This exploratory study contrasts arguments about justice from a mitigation perspective, with those from an adaptation perspective and draws insights about the contours of politically acceptable climate policy. Using think-aloud protocols and a structured elicitation approach with members of the lay public to generate quantitative and qualitative data, this study suggests that the two types of climate policy trigger different sets of arguments about justice. When asked about mitigation burden-sharing participants overwhelmingly invoke arguments about causality. In contrast, in discussions of adaptation participants emphasized the needs of the afflicted parties and their ability to cope. Furthermore, social and spatial distances were not a factor in allocation of mitigation burdens, but were used to discount the distribution of compensation towards adaptation. These initial data about public perceptions of justice in this area suggest that the public would view adaptation and mitigation as complements not substitutes. These findings also highlight the importance of exploring public reactions to the sub-components of climate policy individually.     

Scientific uncertainty and climate change: Part II. Uncertainty and mitigation

In public debate surrounding climate change, scientific uncertainty is often cited in connection with arguments against mitigative action. This article examines the role of uncertainty about future climate change in determining the likely success or failure of mitigative action. We show by Monte Carlo simulation that greater uncertainty translates into a greater likelihood that mitigation efforts will fail to limit global warming to a target (e.g., 2 °C). The effect of uncertainty can be reduced by limiting greenhouse gas emissions. Taken together with the fact that greater uncertainty also increases the potential damages arising from unabated emissions (Lewandowsky et al. 2014), any appeal to uncertainty implies a stronger, rather than weaker, need to cut greenhouse gas emissions than in the absence of uncertainty.     

Renewable and low-carbon energies as mitigation options of climate change for China

This article discusses how renewable and low-carbon energies can serve as mitigation options of climate change in China’s power sector. Our study is based on scenarios developed in PowerPlan, a bottom-up model simulating a countries’ power sector and its emissions. We first adjusted the model to China’s present-day economy and power sector. We then developed different scenarios based on story lines for possible future developments in China. We simulated China’s carbon-based electricity production system of today and possible future transitions towards a low-carbon system relying on renewable and low-carbon energies. In our analysis, we compare the business-as-usual scenarios with more sustainable energy scenarios. We found that by increasing the share of renewable and nuclear energies to different levels, between 17% and 57% of all CO₂ emissions from the power sector could be avoided by 2030 compared to the business-as-usual scenario. We also found that electricity generation costs increase when more sustainable power plants are installed. As a conclusion, China has two options: choosing for high climate change mitigation and high costs or choosing for moderate climate change mitigation and moderate costs. In case high climate change mitigation will be chosen, development assistance is likely to be needed to cover the costs.