Why the IPCC should evolve in response to the UNFCCC bottom-up strategy adopted in Paris? An opinion from the French Association for Disaster Risk Reduction

The levels of greenhouse gases in the atmosphere keep increasing every year, and despite the adoption of the Paris agreement, one cannot expect any significant dip in the trend in the near future. We may therefore legitimately question the efficiency of the current governance system, notably concerning the interplay between science and policy. The strategy adopted by the UNFCCC in Paris contrasts with the strategy adopted in Kyoto, as it endorses a dynamic that is more bottom-up. Its success will depend greatly on the ability of the actors to mobilise on climate issues and to find ways to work together. Scientific expertise has a key role to play to this respect. This paper is a reflection led by the French Association for Disaster Risk Reduction on how the Intergovernmental Panel on Climate Change could evolve in order to usefully accompany that strategy. Introducing more reflexivity in the assessment process and widening aspects of the expertise to a more diverse and transdisciplinary range of actors could improve the treatment of uncertainties, multi-scale interactions and the appropriation of expertise, as well as the integration of adaptation and mitigation policies. In practical terms, this could involve more working groups, which could become more focused, drawing up shorter but more frequent reports, and taking account of the “grey” expert literature. The implementation of such an approach merits further investigation, because these improvements could help address the governance challenges in climate change.     

Climate change and human health in Latin America: drivers, effects, and policies

Many people would be increasingly affected by living under critical conditions in Latin America if, as expected, global warming aggravates disease and pest transmission processes. Heat waves and air pollution would increase heat-related diseases and illness episodes in large cities. Fire smoke has been associated with irritation of the throat, lung and eyes, and respiratory problems. Climate extreme increases associated with climate change would cause physical damage, population displacement, and adverse effects on food production, freshwater availability and quality. It would also increase the risks of infectious and vector-borne diseases. Climate change impacts the geographical range, seasonality, and the incidence rate of vector-borne diseases, such as malaria. Climate-related ecological changes may expand cholera transmission, particularly among populations in low-laying tropical coastal areas. El Niño conditions may affect the incidence of infectious diseases, such as malaria. Ocean warming would increase temperature-sensitive toxins produced by phytoplankton, which could cause more frequent contamination of seafood. A clearer understanding on the current role of climate change in disease patterns will be able to improve forecasts of potential future impacts of projected climate change and support action to reduce such impacts.     

Hydrologic and land use impacts on vegetation growth and NPP at the watershed scale in a semi-arid environment

Significant, adverse climatic change and drastically increased demographic pressure have strongly affected, in recent years, the hydrology and environment in the semi-arid Sahel region of West Africa. Marked rain deficits have coincided with increased water runoff, meaning less water availability for the vegetation. Conversely, changes in vegetation cover have had strong repercussions on the hydrologic cycle. To study these phenomena, the coupling of two explicit, process-based models, of catchment hydrology and of mixed vegetation cover, respectively, has been undertaken and applied to a 2 km² site in Niger. Some of the first significant results are presented herein. Some are consistent with intuitive judgments that can be made in the absence of a coupled model, others are much less so and show that representation through model coupling of hydrosphere/biosphere interactions is essential to produce more reliable analyses and projections. In particular, it is found that the relation of biomass productivity to rainfall under this dry, water-limited climate is not as straightforward as one would expect, more specifically, that its main control may not be the total season rainfall.     

Risks posed by climate change to the delivery of Water Framework Directive objectives in the UK

The EU Water Framework Directive (WFD) is novel because it integrates water quality, water resources, physical habitat and, to some extent, flooding for all surface and groundwaters and takes forward river basin management. However, the WFD does not explicitly mention risks posed by climate change to the achievement of its environmental objectives. This is despite the fact that the time scale for the implementation process and achieving particular objectives extends into the 2020s, when climate models project changes in average temperature and precipitation. This paper begins by reviewing the latest UK climate change scenarios and the wider policy and science context of the WFD. We then examine the potential risks of climate change to key phases of the River Basin Management Process that underpin the WFD (such as characterisation of river basins and their water bodies, risk assessments to identify pressures and impacts, programmes of measures (POMs) options appraisal, monitoring and modelling, policy and management activities). Despite these risks the WFD could link new policy and participative mechanisms (being established for the River Basin Management Plans) to the emerging framework of national and regional climate change adaptation policy. The risks are identified with a view to informing policy opportunities, objective setting, adaptation strategies and the research agenda. Key knowledge gaps have already been identified during the implementation of the WFD, such as the links between hydromorphology and ecosystem status, but the overarching importance of linking climate change to these considerations needs to be highlighted. The next generation of (probabilistic) climate change scenarios will present new opportunities and challenges for risk analysis and policy-making.     

How developing countries can engage in GHG reduction: a case study for China

It has been clearly recognized that future global climate change will limit the possibilities for sustainable development in China. To minimize these negative effects, as a practical strategy, we suggest that the Chinese government engage in international cooperation as a key contributor in the prevention of global warming. This suggestion results from numerical estimations of China’s greenhouse gas (GHG) emission trends accompanied with economic growth up to 2100. The results show that China’s gross domestic product (GDP), measured in terms of purchasing power parity (PPP), may overtake the sum of the GDPs of the United States and Canada in 2020. It is predicted that GDP per capita may reach US$20,000 and $80,000 in 2050 and 2100, respectively; meanwhile, CO₂ emissions in China will increase from 6.6 billion tons (in carbon equivalent units) in 1990 to 54.6 billion tons in 2100. This means that the global peak concentration of GHG cannot be practically reduced without significant contributions from China. For international cooperation in mitigating global climate change, we introduce a new option, “per-capita emission restricted by assigned amount,” as an accounting rule for GHG reduction. This baseline classifies global CO₂ reduction actions into three categories: compulsory reduction, self-imposed reduction, and voluntary reduction. We suggest that China contribute to world CO₂ reduction according to the following timetable: voluntary reduction until 2012, self-imposed reduction until 2020, and compulsory reduction from 2020. The simulation results also indicate that China can benefit from this strategy in terms of improvements in its domestic economy and environment, for instance, by reducing fossil fuel consumption and the emission of pollutants.

Do energy prices affect employment? Decomposed international evidence

This paper analyzes the energy price-employment nexus and contributes to the literature by showing that it is important to decompose the regulatory effect into demand, cost, and factor-shift effects. This is done by means of a cross-country multi-sectoral dataset. The results show that both rising energy prices and shadow prices of energy have no significant effect on net employment when the manufacturing sectors only are analyzed. While finding significant variations across countries, the average employment effects become significantly positive once jobs in the economy as a whole are considered. This change is driven mainly by larger positive cost effects, which more than offset the negative demand effects and reductions in the positive factor-shift effects. Moreover, the paper reveals that the often implemented approach of using a simple regulation regressor, instead of decomposing the employment effect, can result in biased estimates.     

Cumulative carbon emissions and economic policy: In search of general principles

We exploit recent advances in climate science to develop a physically consistent, yet surprisingly simple, model of climate policy. It seems that key economic models have greatly overestimated the delay between carbon emissions and warming, and ignored the saturation of carbon sinks that takes place when the atmospheric concentration of carbon dioxide rises. This has important implications for climate policy. If carbon emissions are abated, damages are avoided almost immediately. Therefore it is optimal to reduce emissions significantly in the near term and bring about a slow transition to optimal peak warming, even if optimal steady-state/peak warming is high. The optimal carbon price should start relatively high and grow relatively fast.     

Temperature effects on mortality and household adaptation: Evidence from China

This paper examines the effects of extreme temperatures on mortality rates, using random year-to-year variation in temperature based on county-level panel data from China. The analysis finds a robust, U-shaped relationship between temperature and mortality rates, indicating that extremely cold or hot temperatures lead to excess deaths. The heat-related (cold-related) effect is 3.5 times (3.2 times) as large as previous findings that used U.S. data, and it is especially large for the elderly population, mainly due to excess deaths caused by cardiovascular diseases. Applying these results to climate change predictions from Hadley Centre Global Environmental Model shows that by 2061–2080 the annual mortality rate is likely to increase by 14.2% if global greenhouse gas emissions continue to rise throughout the 21st century, the estimated health cost of which is around 0.98 trillion Chinese Yuan per year. The paper also explores households’ adaptation behaviors to extreme temperatures. It finds that although urban households adaptively increase energy consumption when they are exposed to cold temperatures and purchase more air conditioners on hot and cold days, rural households are unresponsive to temperature fluctuations. This finding implies that rural people may be more resource constrained and suffer more when extreme temperatures occur.     

CEO education and corporate environmental footprint

We analyze the effect of CEO education on environmental decision-making. Using a unique sample of Danish firms from 1996 to 2012, we find that CEO education significantly improves firms' energy efficiency. We seek to derive causality using health shocks: the hospitalization of highly educated CEOs induces a drop in energy efficiency, whereas the hospitalization of less educated CEOs does not have any significant effect. Exploring the mechanisms at play, we show that our results are largely driven by advanced education in business degrees. Moreover, we show that CEO education is associated with greater environmental awareness: highly educated CEOs exhibit greater concerns for climate change, as measured by a survey of social preferences, and drive more environmentally efficient cars. Taken together, our findings suggest that education shapes managerial styles giving rise to greater sustainability in corporate actions.     

Learning and climate feedbacks: Optimal climate insurance and fat tails

We study the effect of potentially severe climate change on optimal climate change policy, accounting for learning and uncertainty in the climate system. In particular, we test how fat upper tailed uncertainty over the temperature change from a doubling of greenhouse gases (the climate sensitivity), affects economic growth and emissions policy. In addition, we examine whether and how fast uncertainties could be diminished through Bayesian learning. Our results indicate that while overall learning is slow, the mass of the fat tail diminishes quickly, since observations near the mean provide evidence against fat tails. We denote as “tail learning” the case where the planner rejects high values of the climate sensitivity with high confidence, even though significant uncertainty remains. Fat tailed uncertainty without learning reduces current emissions by 38% relative to certainty, indicating significant climate insurance, or paying to limit emissions today to reduce the risk of very high temperature changes, is optimal. However, learning reduces climate insurance by about 50%. The optimal abatement policy is strongly influenced by the current state of knowledge, even though greenhouse gas (GHG) emissions are difficult to reverse. Once the mass of the fat tail diminishes, the remaining uncertainty is largely irrelevant for optimal emissions policy.