Is it hot in here or is it just me? Temperature anomalies and political polarization over global warming in the American public

Do temperature anomalies affect political polarization over global warming? Americans’ attitudes about global warming are affected by whether they reside in states experiencing unseasonably warm (or cold) temperatures versus those experiencing milder temperatures. Specifically, in terms of causal attribution, political polarization over global warming is more pronounced in states experiencing temperature anomalies. Using pooled data collected during 2013–2014, this study utilizes logistic regression to explore how temperature anomalies exacerbate the political polarization among Americans over perceptions of whether global warming impacts are immediately evident as well as the attribution of global warming to human activity. Results indicate that very cold or warm temperature anomalies from a 5-year baseline predict perceptions of global warming impacts and exacerbate existing political polarization over the causal attribution of global warming. These effects are particularly noticeable among Democrats. This analysis provides a contribution to understanding how temperature anomalies from the recent past shape the sociophysical context of global warming attitudes.     

Relevance of soil moisture for seasonal atmospheric predictions: is it an initial value problem?

Ensembles of boreal summer atmospheric simulations, spanning a 15-year period (1979–1993), are performed with the ARPEGE climate model to investigate the influence of soil moisture on climate variability and potential predictability. All experiments are forced with observed monthly mean sea surface temperatures. In addition to a control experiment with interactive soil moisture boundary conditions, two sensitivity experiments are performed. In the first, the interannual variability of the deep soil moisture is removed during the whole season, through a relaxation toward the monthly mean model climatology. In the second, only the variability of the initial soil moisture conditions is suppressed. While it is shown that soil moisture strongly contributes to the climate variability simulated in the control experiment, an analysis of variance indicates that soil moisture does not represent a significant source of predictability in most continental areas. The main exception is the North American continent, where climate predictability is clearly reduced through the use of climatological initial conditions. Using climatological soil moisture boundary conditions does not lead to strong and homogeneous impacts on potential predictability, thereby suggesting that the climate signals driven by the sea surface temperature variability are not generally amplified by interactive soil moisture and that the relevance of soil moisture for seasonal forecasting is mainly an initial value problem.     

Job losses and political acceptability of climate policies: why the ‘job-killing’ argument is so persistent and how to overturn it

Political acceptability is an essential issue in choosing appropriate climate policies. Sociologists and behavioural scientists recognize the importance of selecting environmental policies that have broad political support, while economists tend to compare different instruments first on the basis of their efficiency, and then by assessing their distributional impacts and thus their political acceptability. This paper examines case-study and empirical evidence that the job losses ascribed (correctly or incorrectly) to climate policies have substantial impacts on the willingness of affected workers to support these policies. In aggregate, the costs of these losses are significantly smaller than the benefits, both in terms of health and, probably, of labour market outcomes, but the losses are concentrated in specific areas, sectors and social groups that have been hit hard by the great recession and international competition. Localized contextual effects, such as peer group pressure, and politico-economic factors, such as weakened unions and tightened government budgets, amplify the strength and the persistence of the ‘job-killing’ argument. Compensating for the effects of climate policies on ‘left-behind’ workers appears to be the key priority to increase the political acceptability of such policies, but the design of compensatory policies poses serious challenges.

Key policy insights

• Public perception of, and support for, climate policies is substantially reduced in the presence of large negative shocks, especially job losses.

• Climate policies can be perceived as negative for employment, especially in areas where polluting industries represent a large share of employment and in occupations and sectors already damaged by globalization and automation.

• Policymakers should distinguish between small and large distributional effects of climate policies, and find the appropriate combination of revenue recycling schemes, industrial and retraining policies as well as compensation packages to increase the support for such policies.

     

Why is Indian Ocean warming consistently?

Observations have shown that the Indian Ocean is consistently warming and its warm pool is expanding, particularly in the recent decades. This paper attempts to investigate the reason behind these observations. Under global warming scenario, it is expected that the greenhouse gas induced changes in air–sea fluxes will enhance the warming. Surprisingly, it is found that the net surface heat fluxes over Indian Ocean warm pool (IOWP) region alone cannot explain the consistent warming. The warm pool area anomaly of IOWP is strongly correlated with the sea surface height anomaly, suggesting an important role played by the ocean advection processes in warming and expansion of IOWP. The structure of lead/lag correlations further suggests that Oceanic Rossby waves might be involved in the warming. Using heat budget analysis of several Ocean data assimilation products, it is shown that the net surface heat flux (advection) alone tends to cool (warm) the Ocean. Based on above observations, we propose an ocean-atmosphere coupled positive feedback mechanism for explaining the consistent warming and expansion of IOWP. Warming over IOWP induces an enhancement of convection in central equatorial Indian ocean, which causes anomalous easterlies along the equator. Anomalous easterlies in turn excite frequent Indian ocean Dipole events and cause anti-cyclonic wind stress curl in south-east and north-east equatorial Indian ocean. The anomalous wind stress curl triggers anomalous downwelling oceanic Rossby waves, thereby deepening the thermocline and resulting in advection of warm waters towards western Indian ocean. This acts as a positive feedback and results in more warming and westward expansion of IOWP.     

Safe climate policy is affordable—12 reasons

There is a widespread sense that a sufficiently stringent climate mitigation policy, that is, a considerable reduction of greenhouse gas emissions to avoid extreme climate change, will come with very high economic costs for society. This is supported by many cost–benefit analyses (CBA) and policy cost assessments of climate policy. All of these, nevertheless, are based on debatable assumptions. This paper will argue instead that safe climate policy is not excessively expensive and is indeed cheaper than suggested by most current studies. To this end, climate CBA and policy cost assessments are critically evaluated, and as a replacement twelve complementary perspectives on the cost of climate policy are offered.     

How is the Indian Ocean Subtropical Dipole excited?

Based on experiments using a coupled general circulation model which resolves tropical ocean–atmosphere coupled phenomena such as El Niño/Southern Oscillation (ENSO) and the Indian Ocean Dipole, forcing mechanisms of the Indian Ocean subtropical dipole (IOSD) are investigated. In the control experiment, as in the observation, several types of the IOSD are generated by the variations in the Mascarene High during austral summer and characterized by a dipole pattern of sea surface temperature (SST) anomalies in the northeastern and southwestern parts of the southern Indian Ocean. In another experiment, where the SST outside the southern Indian Ocean is nudged toward the monthly climatology of the simulated SST, one type of the IOSD occurs, but it is less frequent and associated with the zonal wavenumber four pattern of equivalently barotropic geopotential height anomalies in high latitudes, suggesting an interesting link with the Antarctic Circumpolar Wave. This indicates that, even without the atmospheric teleconnection from tropical coupled climate modes, the IOSD may develop in association with the atmospheric variability in high latitudes of the Southern Hemisphere. In the other experiment, where only the southern Indian Ocean and the tropical Pacific are freely interactive with the atmosphere, two types of both positive and negative IOSD occur. Since the occurrence frequency of the IOSD significantly increases as compared to the second experiment, this result confirms that the atmospheric teleconnection from ocean-atmosphere coupled modes in the tropical Pacific such as ENSO may also induce the variations in the Mascarene High that generate the IOSD. The present research, even within the realm of model studies, shows clearly that the predictability of the IOSD in mid-latitudes is related to both low and high-latitudes climate variations.     

Polar amplification: is atmospheric heat transport important?

Surface albedo feedback is widely believed to be the principle contributor to polar amplification. However, a number of studies have shown that coupled ocean-atmosphere models without ice albedo feedbacks still produce significant polar amplification in 2 × CO₂ runs due to atmospheric heat transports and their interaction with surface conditions. In this article, the relative importance of atmospheric heat transport and surface albedo is assessed using a conceptual 2-box energy balance model in a variety of different model climates. While both processes are shown to independently contribute to the polar amplified response of the model, formal feedback analysis indicates that a strong surface albedo response will tend to reduce the effect of atmospheric heat transport in the full model. We identify several scenarios near the present day climate in which, according to this formal feedback analysis, atmospheric heat transport plays no role in shaping the equilibrium warming response to uniform forcing. However, a closer analysis shows that even in these scenarios the presence of atmospheric heat transport feedback does play a significant role in shaping the trajectory by which the climate adjusts to its new equilibrium.     

PPP Correction of the IPCC Emission Scenarios – Does it Matter?

Ian Castles and David Henderson have criticized IPCC’s Special Report on Emissions Scenarios (SRES) (IPCC: 2000, Special Report on Emissions Scenarios, Intergovernmental Panel on Climate Change (IPCC), Cambridge University Press, Cambridge, 595 pp. http://www.grida.no/climate/ipcc/emission/index.htm) for using market exchange rates (MER) instead of purchasing power parities (PPP), when converting regional GDP into a common denominator. The consequence is that poor countries generally appear to be poorer than they actually are. An overstated income gap between the rich and poor countries in the base year gives rise to projections of too high economic growth in the poor countries, because the scenarios are constructed with the aim of reducing the income gap. Castles and Henderson claim that overstated economic growth means that greenhouse gas emissions are overstated as well. However, because closure of the emission-intensity gap between the rich and the poor parts of the world is another important driving force in the scenarios, we argue that the use of MER in the SRES scenarios has not caused an overestimation of the global emission growth because, as far as global emissions are concerned, the overstated income gap is effectively neutralized by the overstated emission-intensity gap.     

How predictable is the northern hemisphere summer upper-tropospheric circulation?

The retrospective forecast skill of three coupled climate models (NCEP CFS, GFDL CM2.1, and CAWCR POAMA 1.5) and their multi-model ensemble (MME) is evaluated, focusing on the Northern Hemisphere (NH) summer upper-tropospheric circulation along with surface temperature and precipitation for the 25-year period of 1981–2005. The seasonal prediction skill for the NH 200-hPa geopotential height basically comes from the coupled models’ ability in predicting the first two empirical orthogonal function (EOF) modes of interannual variability, because the models cannot replicate the residual higher modes. The first two leading EOF modes of the summer 200-hPa circulation account for about 84% (35.4%) of the total variability over the NH tropics (extratropics) and offer a hint of realizable potential predictability. The MME is able to predict both spatial and temporal characteristics of the first EOF mode (EOF1) even at a 5-month lead (January initial condition) with a pattern correlation coefficient (PCC) skill of 0.96 and a temporal correlation coefficient (TCC) skill of 0.62. This long-lead predictability of the EOF1 comes mainly from the prolonged impacts of El Niño-Southern Oscillation (ENSO) as the EOF1 tends to occur during the summer after the mature phase of ENSO. The second EOF mode (EOF2), on the other hand, is related to the developing ENSO and also the interdecadal variability of the sea surface temperature over the North Pacific and North Atlantic Ocean. The MME also captures the EOF2 at a 5-month lead with a PCC skill of 0.87 and a TCC skill of 0.67, but these skills are mainly obtained from the zonally symmetric component of the EOF2, not the prominent wavelike structure, the so-called circumglobal teleconnection (CGT) pattern. In both observation and the 1-month lead MME prediction, the first two leading modes are accompanied by significant rainfall and surface air temperature anomalies in the continental regions of the NH extratropics. The MME’s success in predicting the EOF1 (EOF2) is likely to lead to a better prediction of JJA precipitation anomalies over East Asia and the North Pacific (central and southern Europe and western North America).     

A Chinese commitment to commit: can it break the negotiation stall?

Preparatory talks to the next round of negotiations seem to indicate that a comprehensive agreement to mitigate climate change will not be easily attainable, despite the intentions of the US administration and the high expectations surrounding the Copenhagen meeting. One key reason is to what extent fast growing economies, and especially China, should take actions to reduce their growth of emissions. This paper argues that a turning point for international negotiations on climate change could be achieved if China were to agree on carbon obligations in the future. Results from modelling work suggest that the optimal investment behaviour is to anticipate the implementation of a climate policy by roughly 10 years, and that thus future commitments—if credible—could lead to significantly earlier steps towards carbon mitigation. If fast growing economies, and foremost China, believe in the long term objective of global stabilization of carbon concentrations, it might be economically rationale to sign on future targets, provided developed countries take on immediate action. Such a provision could be beneficial for both the developing and developed world.     

The western Mediterranean climate: how will it respond to global warming?

The paper discusses the newly produced temperature and precipitation series from instrumental observations in the Western Mediterranean (WM) area, dating back to 1654. The two series had a continuous swing and unstable coupling passing from correlation to anti-correlation. Only after 1950 are they permanently anti-correlated with increasing temperature and decreasing precipitation. It is not clear how long this coupling will persist. The analysis of the correlation between the Northern Hemisphere (NH) and the WM temperature anomalies and their trends shows a certain variability from 1850 to 1950; later a strong coupling between NH and WM. Results suggest that the WM climate is approaching a turning point that might locally oppose the adverse effects of Global Warming.     

What is the “sign” of the atmospheric-electric field?

Summary The sign of the vector representing the atmospheric electric field has recently been subject of debate. For the sake of clarity, it is recommended to refer only to a normal or reversed clear-weather potential gradient.

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Zusammenfassung Eine in letzter Zeit entstandene Diskussion darüber, welches Vorzeichen dem Vektor des atmosphärisch-elektrischen Feldes bzw. des Potentialgefälles zuerkannt werden soll, erscheint wenig sinnvoll. Zur Vermeidung künftiger Unklarheiten wird empfohlen, bei der atmosphärischen Elektrizität nur von normaler Schönwetterrichtung und umgekehrter Schönwetterrichtung des Feldes bzw. des Potentialgefälles zu sprechen.

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Résumé Une récente discussion a porté sur le signe qui devait être attribué au vecteur du champ électrique atmosphérique respectivement de son gradient de potentiel. On recommande, pour éviter à l'avenir toute confusion, de ne parler en électricité atmosphérique et quand il s'agit du champ ou du gradient de potentiel, que de «direction normale de beau temps» et de «direction inversée de beau temps».

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Dedicated to Dr.W. Mörikofer on the occasion of his 70th birthday.     

Why is risk aversion unaccounted for in environmental policy evaluations?

U.S. environmental regulations are increasingly influenced by cost-benefit analyses that are performed based on the guidance of the Office of Management and Budget (OMB). The OMB’s Circular A-4 directs Federal agencies to assume “risk neutrality” in conducting regulatory analysis, and in important instances, this guidance is not supported by economic theory. Risk neutrality is computationally convenient, and it can be justified when only the costs and benefits of regulations themselves are uncertain, because these risks are spread across a large population. However, the Circular A-4 does not distinguish between regulations that cause uncertainty and those that reduce pre-existing (i.e. baseline) uncertainty, such as the potential for catastrophic climate change. Basic economic theory shows that risk aversion should be incorporated into evaluations of policies that reduce pre-existing environmental uncertainty. Regulatory analyses generally ignore these risk-reduction benefits, leading to misinformed policymaking. Quantifying risk premiums is difficult and controversial, but no more so than discounting future costs and benefits to present value terms. Similar to how OMB has established discount rates for use in regulatory analyses, a method for when and how to incorporate risk aversion into policy evaluations should replace the blanket guidance for risk neutrality.     

Is it possible to limit global warming to no more than 1.5°C?

This study explores the feasibility of limiting increases in global temperature to 1.5°C above pre-industrial levels. A probabilistic simple climate model is used to identify emissions paths that offer at least a 50% chance of achieving this goal. We conclude that it is more likely than not that warming would exceed 1.5°C, at least temporarily, under plausible mitigation scenarios. We have identified three criteria of emissions paths that could meet the 1.5°C goal with a temporary overshoot of no more than 50 years: early and strong reductions in emissions, with global emissions peaking in 2015 and falling to at most 44–48 GtCO₂e in 2020; rapid reductions in annual global emissions after 2020 (of at least 3–4% per year); very low annual global emissions by 2100 (less than 2–4 GtCO₂e) and falling to zero (or below) in the 22nd century. The feasibility of these characteristics is uncertain. We conclude that the proposed date of review of the 1.5°C goal, set at 2015, may be too late to achieve the necessary scaling up of emissions cuts to achieve this goal.     

How is organic farming performing agronomically and economically in sub-Saharan Africa?

The potential of organic agriculture and agroecological approaches for improving food security in Africa is a controversial topic in global discussions. While there is a number of meta-analyses on the environmental, agronomic and financial performance of organic farming, most of the underlying data stems from on-station field trials from temperate regions. Data from sub-Sahara Africa in particular, as well as detailed real-farm data is scarce. How organic farming is implemented in sub-Saharan Africa and how it performs in a smallholder context remains poorly understood. We applied a novel observational two-factorial research design, which allowed to evaluate the impacts of i) interventions for introducing organic agriculture and ii) specific organic management practices on 1,645 farms from five case studies in Ghana and Kenya, which we closely monitored for 24 months. Among the farmers who have been exposed to the interventions, we found heterogeneous adoption of organic agriculture principles, depending on the intervention. Furthermore, we found rather passive than active organic management among farmers. Most yields and gross margins under organic management remained at similar levels as the conventional values in four of the case studies. In one case study, however, coffee, maize and macadamia nut yields increased by 127–308% and farm-level gross margins over all analysed crops by 292%. Pooling our data across all case studies, we found significantly higher (+144%) farm-level gross margins on organically managed farms than on conventional farms. This indicates the potential of organic and agroecological approaches if implemented well. Based on our observations, we argue for improving the implementation of organic agriculture projects in settings with smallholder farmers. Limited capacities, lack of appropriate inputs and market access are major agronomic and institutional challenges to be addressed. Furthermore, we argue for supporting a differentiated debate about which types of organic farming are really desirable by classifying approaches to organic farming according to i) their intention to work organically and ii) the degree of following the organic principles. This will support the design and implementation of targeted policy interventions for stimulating sustainability of farming systems and rural development.     

How robust is the long-run relationship between temperature and radiative forcing?

This paper examines the robustness of the long-run, cointegrating, relationship between global temperatures and radiative forcing. It is found that the temperature sensitivity to a doubling of radiative forcing is of the order of 2 ± 1°C. This result is robust across the sample period of 1850 to 2000, thus providing further confirmation of the quantitative impact of radiative forcing and, in particular, CO₂ forcing, on temperatures.