Attribution matters: Revisiting the link between extreme weather experience and climate change mitigation responses

The literature suggests that extreme weather experiences have potential to increase climate change engagement by influencing the way people perceive the proximity and implications of climate change. Yet, limited attention has been directed at investigating how individual differences in the subjective interpretation of extreme weather events as indications of climate change moderate the link between extreme weather experiences and climate change attitudes. This article contends that subjective attribution of extreme weather events to climate change is a necessary condition for extreme weather experiences to be translated into climate change mitigation responses, and that subjective attribution of extreme weather to climate change is influenced by the psychological and social contexts in which individuals appraise their experiences with extreme weather. Using survey data gathered in the aftermath of severe flooding across the UK in winter 2013/2014, personal experience of this flooding event is shown to only directly predict perceived threat from climate change, and indirectly predict climate change mitigation responses, among individuals who subjectively attributed the floods to climate change. Additionally, subjective attribution of the floods to climate change is significantly predicted by pre-existing climate change belief, political affiliation and perceived normative cues. Attempts to harness extreme weather experiences as a route to engaging the public must be attentive to the heterogeneity of opinion on the attributability of extreme weather events to climate change.     

The effect of health benefits on climate change mitigation policies

This paper studies the interplay between climate, health, and the economy in a stylized world with eleven heterogeneous regions, with special emphasis on USA, Europe, China, India, and Africa. We introduce health impacts into a simple economic integrated assessment model where both the local cooling effect of SO ₂ and the global warming effect of CO ₂ are endogenous, and investigate how these factors affect the equilibrium path. Regions do not respond in the same way to climate change. In particular, emission abatement rates and health costs depend on the economic and geographical characteristics of each region. Two policy scenarios are considered, Nash and Optimal, for which we present both global and regional results. Results for Africa and China are highlighted.     

Human health as a motivator for climate change mitigation: results from four European high-income countries

Invoking health benefits to promote climate-friendly household behavior has three unique advantages: (i) health co-benefits accrue directly to the acting individual, they are "private goods" rather than public ones; (ii) the evidence base for, and magnitude of health co-benefits is well-established; and (iii) the idea of a healthy life-style is well-engrained in public discourse, much more so than that of a climate-friendly life-style. In previous research, assessing the influence of information on health effects on people’s motivation to adopt mitigation actions, health co-benefits for the individual were typically confounded with collective health co-benefits, for example from pollution reduction. The present research aims to overcome this limitation by providing information on individual health co-benefits that are unconditional on the actions of others (direct health co-benefits). We report effects of this kind of health information on stated willingness to adopt mitigation actions as well as on simulation-based carbon emission reductions in a pre-registered experimental setting among 308 households in 4 mid-size case-study cities in 4 European high-income countries: France, Germany, Norway and Sweden. For each mitigation action from the sectors food, housing, and mobility, half of the sample received the amount of CO₂equivalents (CO₂-eq) saved and the financial costs or savings the respective action generated. The other half additionally received information on direct health co-benefits, where applicable. For households receiving information on direct health co-benefits, we find a higher mean willingness to adopt food and housing actions, and a greater proportion very willing to adopt one or more mitigation actions (OR 1.86, 95% CI 1.1, 3.12); and a greater simulated reduction in overall carbon footprint: difference in percent reduction -2.70%, (95% CI -5.34, -0.04) overall and -4.45%, (95% CI -8.26, -0.64) for food. Our study is the first to show that providing information on strictly unconditional, individual health co-benefits can motivate households in high-income countries to adopt mitigation actions.     

The economics of leadership in climate change mitigation

Which kind of reaction can a nation or group of nations expect when leading by example in climate policy? This synthesis article describes possible positive reaction mechanisms from different fields of economics, some of which have scarcely been linked to climate economics previously. One effect may be behavioural, a reaction motivated by fairness, reciprocity, or norms. Second, other nations may interpret the leader's action as a signal on his preference or the value of the objective and adjust their own policy based on the new information. Third, the leader may provide a service to other nations, which decreases their costs and risks. The followers could benefit by learning successful policies, adopting technologies, and obtaining information on the cost of environmental policy. All of these mechanisms have in common that the leader sets an example with the intention of motivating others to contribute to the public good.

Policy relevance

A large body of both theoretical and empirical evidence shows that leading by example in climate change mitigation by a small group of nations has important potential for motivating other nations to follow. Modern economics has identified a range of mechanisms to explain why simple free-riding is unlikely to dominate the reaction to leadership. One such mechanism is described by behavioural economics. Humans often behave as conditional cooperators, meaning that they are willing to do their bit once a leader has done his. A second mechanism is the transmission of a credible signal that the leader considers climate change mitigation to be important. Finally, the leader gains knowledge, which spills over to other countries and thus moves their cost–benefit ratio in favour of mitigation. This evidence implies that leadership provides a promising alternative to stimulate the global cooperation that will eventually be needed to stabilize the climate.     

Energy efficiency potentials for global climate change mitigation

Energy efficiency is one of the main options for mitigating climate change. An accurate representation of various mechanisms of energy efficiency is vital for the assessment of its realistic potential. Results of a questionnaire show that the EMF27 models collectively represent known channels of energy efficiency reasonably well, addressing issues of energy efficiency barriers and rebound effects. The majority of models, including general equilibrium models, have an explicit end-use representation for the transportation sector. All participating partial equilibrium models have some capability of reflecting the actual market behavior of consumers and firms. The EMF27 results show that energy intensity declines faster under climate policy than under a baseline scenario. With a climate policy roughly consistent with a global warming of two degrees, the median annual improvement rate of energy intensity for 2010–2030 reaches 2.3 % per year [with a full model range of 1.3–2.9 %/yr], much faster than the historical rate of 1.3 % per year. The improvement rate increases further if technology is constrained. The results suggest that the target of the United Nations’ “Sustainable Energy for All” initiative is consistent with the 2-degree climate change target, as long as there are no technology constraints. The rate of energy intensity decline varies significantly across models, with larger variations at the regional and sectoral levels. Decomposition of the transportation sector down to a service level for a subset of models reveals that to achieve energy efficiency, a general equilibrium model tends to reduce service demands while partial equilibrium models favor technical substitution.     

Representing global climate change,adaptation and mitigation

The diagrammatic representation of climate change, adaptation and mitigation is important in conceptualizing the problem, identifying important feedbacks, and communicating between disciplines. The Synthesis Report of the IPCC's Third Assessment Report, 2001, uses a “cause and effect” approach developed in the integrated assessment literature. This viewpoint reviews this approach and suggests an alternative, based on stocks and flows. The alternative gives a much richer representation of the problem so that it includes the enhanced greenhouse effect, ancillary benefits of mitigation, the distinction between climate-change and other stresses on natural systems, and a more refined distinction between adaptation and mitigation.     

Governing agriculture-forest landscapes to achieve climate change mitigation

This introduction to the special section on “Governing Agriculture-Forest Landscapes to Achieve Climate Change Mitigation” reviews external interventions to improve forest conditions and reduce deforestation, and by extension, influence carbon storage in agriculture-forest landscapes. The review is based on a careful survey of 123 cases of project-based and policy interventions to influence land use and forest cover outcomes. We propose that outcomes of interventions can be explained in terms of rights, incentives, and technologies related to land use and apply this framework to examine 12 types of interventions in agriculture-forest landscapes. The analysis of the identified 123 cases raises concerns about consistency of data and comparability of cases. Our preliminary evidence suggests limited association between the stated objective of an intervention and its success. This evidence also suggests that smaller scale and effective enforcement may be positively associated with improved forest outcomes. But the effectiveness of interventions across different agriculture-forest landscapes varies and available evidence does not permit easy generalizations. The variable effects of interventions across different agriculture-forest landscapes point to the need to better understand the forms and functions of interventions and to problems associated with assessing their relative efficacy.     

The water impacts of climate change mitigation measures

A variety of proposed activities to mitigate greenhouse gas emissions will impact on scarce water resources, which are coming under increasing pressure in many countries due to population growth and shifting weather patterns. However, the integrated analysis of water and carbon impacts has been given limited attention in greenhouse mitigation planning. In this Australian case study, we analyse a suite of 74 mitigation measures ranked as highest priority by one influential analysis, and we find that they have highly variable consequences for water quantity. We find: (1) The largest impacts result from land-based sequestration, which has the potential to intercept large quantities of water and reduce catchment yields, estimated to exceed 100 Mm³/MtCO₂-e of carbon mitigated (100,000 l per tonne CO₂-e). (2) Moderate impacts result from some renewable power options, including solar thermal power with a water cost estimated at nearly 4 Mm³/MtCO₂-e. However, the water impacts of solar thermal power facilities could be reduced by designing them to use existing power-related water supplies or to use air or salt-water cooling. (3) Wind power, biogas, solar photovoltaics, energy efficiency and operational improvements to existing power sources can reduce water demand through offsetting the water used to cool thermal power generation, with minor savings estimated at 2 Mm³/MtCO₂-e and amounting to nearly 100 Mm³ of water saved in Australia per annum in 2020. This integrated analysis significantly changes the attractiveness of some mitigation options, compared to the case where water impacts are not considered.     

Beyond headline mitigation numbers: we need more transparent and comparable NDCs to achieve the Paris Agreement on climate change

Nationally determined contributions (NDCs) were key to reaching the Paris Agreement and will be instrumental in implementing it. Research was quick to identify the ‘headline numbers’ of NDCs: if these climate action plans were fully implemented, global mean warming by 2100 would be reduced from approximately 3.6 to 2.7°C above pre-industrial levels (Höhne et al. Climate Pol 17:1–17, 2016; Rogelj et al. Nature 534:631–639, 2016). However, beyond these headline mitigation numbers, NDCs are more difficult to analyse and compare. UN climate negotiations have so far provided limited guidance on NDC formulation, which has resulted in varying scopes and contents of NDCs, often lacking details concerning ambitions. If NDCs are to become the long-term instrument for international cooperation, negotiation, and ratcheting up of ambitions to address climate change, then they need to become more transparent and comparable, both with respect to mitigation goals, and to issues such as adaptation, finance, and the way in which NDCs are aligned with national policies. Our analysis of INDCs and NDCs (Once a party ratifies the Paris Agreement, it is invited to turn its Intended Nationally Determined Contribution (INDC) into an NDC. We refer to results from our INDC analysis rather than our NDC analysis in this commentary unless otherwise stated.) shows that they omit important mitigation sectors, do not adequately provide details on costs and financing of implementation, and are poorly designed to meet assessment and review needs.     

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.     

The effect of vulnerability on climate change mitigation policies

Climate change is likely to adversely affect many countries throughout the world, but the responses of different countries to this threat vary widely. Attempts to explain the differences in countries’ mitigative policies have been largely deficient. This study seeks to assess the degree to which vulnerability may improve the level of explanation of adopted mitigation policies, studying over 90 countries between 1990 and 2011. Vulnerability is defined to be comprised of two basic factors: impacts (expected damages due to climate change) and adaptive capacity (the ability to adjust to these damages). As there may be a gap between declared and implemented policies, these components of mitigation policy are examined separately. In addition, other variables which mediate between these ‘extreme ends’ of mitigation policies are tested.The effect of vulnerability on climate change mitigation policies is examined by multiple regressions, incorporating a wide range of control variables. The results indicate that climate impacts do not affect mitigation policies. Adaptive capacity has a positive effect on the level of declared policy, but this effect becomes insignificant once implemented policy is examined. However, other tests suggest a possible transition from declarations to actions by high adaptive capacity countries. This finding suggests that high adaptive capacity countries do not view mitigation and adaptation as substitutes. Further analyses indicate that the insignificancy of impacts is caused by the uncertainty in their assessment.     

Bookkeeping rather than climate policy making: national mitigation strategies in Western Europe

Climate change mitigation is a wicked problem that cuts horizontally across sectors and vertically across levels of government. To address it effectively, governments around the world, in particular in the EU, have developed several generations of multi-sectoral national mitigation strategies (NMS) since the early 1990s. Although NMS became the main effort to systematically coordinate mitigation policies, few works have studied them comparatively so far. The present article fills this gap by analysing how the EU-15 group of countries operationalized climate protection through NMS. First, we introduce the three roles policy strategies usually aim to fulfil: besides being policy documents they also represent governance processes (supposed to coordinate sectoral implementation), and capacity-building efforts. Empirically, we then explore the rationale, origins and prevalence of NMS. Subsequently, we characterize them as policy documents (with regards to their contents and structures) and as governance processes that address capacity building only implicitly. Based on existing assessments we finally review some performance indications of NMS. We find that in particular second- and third-generation NMS aimed to take their governance function seriously but resembled ‘lacklustre bookkeeping' of emissions, targets and mitigation options. Instead of approximating NMS towards their obviously overcharging governance function, we suggest to recalibrate them towards their communication and capacity-building function in a way that goes beyond bookkeeping.

Policy relevance

The present article shows that NMS fail to effectively govern climate change mitigation across a broad range of sectoral policy domains. Since most European countries have adopted not one but up to three generations of NMS since the 1990s, this finding is highly relevant for them – and for all others aiming to adopt similarly broad strategies. Instead of piling one strategy on top of another irrespective of their implementation, and instead of abolishing mitigation strategies altogether, we recommend recalibrating them towards what they can realistically accomplish: effective communication and capacity building so that NMS can advance from lacklustre bookkeeping to actively promoting a government-wide climate change mitigation vision. The article can help governments to realise that renewing integrated strategies such as NMS without overhauling them comes close to flogging a dead horse.     

Land restoration in food security programmes: synergies with climate change mitigation

Food-insecure households in many countries depend on international aid to alleviate acute shocks and chronic shortages. Some food security programmes (including Ethiopia’s Productive Safety Net Program–PSNP – which provides a case study for this article) have integrated aid in exchange for labour on public works to reduce long-term dependence by investing in the productive capacity and resilience of communities. Using this approach, Ethiopia has embarked upon an ambitious national programme of land restoration and sustainable land management. Although the intent was to reduce poverty, here we show that an unintended co-benefit is the climate-change mitigation from reduced greenhouse gas (GHG) emissions and increased landscape carbon stocks. The article first shows that the total reduction in net GHG emissions from PSNP’s land management at the national scale is estimated at 3.4 million?Mg?CO₂e?y^?1 – approximately 1.5% of the emissions reductions in Ethiopia’s Nationally Determined Contribution for the Paris Agreement. The article then explores some of the opportunities and constraints to scaling up of this impact.

Key policy insights

• Food security programmes (FSPs) can contribute to climate change mitigation by creating a vehicle for investment in land and ecosystem restoration.

• Maximizing mitigation, while enhancing but not compromising food security, requires that climate projections, and mitigation and adaptation responses should be mainstreamed into planning and implementation of FSPs at all levels.

• Cross-cutting oversight is required to integrate land restoration, climate policy, food security and disaster risk management into a coherent policy framework.

• Institutional barriers to optimal implementation should be addressed, such as incentive mechanisms that reward effort rather than results, and lack of centralized monitoring and evaluation of impacts on the physical environment.

• Project implementation can often be improved by adopting best management practices, such as using productive living livestock barriers where possible, and increasing the integration of agroforestry and non-timber forest products into landscape regeneration.

     

Risk and return of project-based climate change mitigation: a portfolio approach

We present a framework for evaluating the risks of investments in climate change mitigation projects to generate emission credits. Risk factors that influence the quantity of emission credits are identified for six project types. Since not all project types are affected by the same factors, diversification is a viable risk reduction strategy. We propose a methodology for quantifying risk and return of such investments, discuss data requirements, and illustrate it using a sample of voluntary projects. In our sample, the returns of an optimally diversified low-risk portfolio are up to 10 times higher than those of single projects, holding risk exposure constant.     

A wedge-based approach to estimating health co-benefits of climate change mitigation activities in the United States

While it has been recognized that actions reducing greenhouse gas (GHG) emissions can have significant positive and negative impacts on human health through reductions in ambient fine particulate matter (PM_2.5) concentrations, these impacts are rarely taken into account when analyzing specific policies. This study presents a new framework for estimating the change in health outcomes resulting from implementation of specific carbon dioxide (CO₂) reduction activities, allowing comparison of different sectors and options for climate mitigation activities. Our estimates suggest that in the year 2020, the reductions in adverse health outcomes from lessened exposure to PM_2.5 would yield economic benefits in the range of $6 to $30 billion (in 2008 USD), depending on the specific activity. This equates to between $40 and $198 per metric ton of CO₂ in health benefits. Specific climate interventions will vary in the health co-benefits they provide as well as in potential harms that may result from their implementation. Rigorous assessment of these health impacts is essential for guiding policy decisions as efforts to reduce GHG emissions increase in scope and intensity.