Search

The idea of modifying cirrus clouds to directly counteract greenhouse gas warming has gained momentum in recent years, despite disputes over its physical feasibility. Previous studies that analyzed modifications of cirrus clouds by seeding of ice nucleating particles showed large uncertainties in both cloud and surface climate responses, ranging from no effect or even a small warming to a globally averaged cooling of about 2.5 °C. We use two general circulation models that showed very different responses in previous studies, ECHAM6-HAM and CESM-CAM5, to determine which radiative and climatic responses to cirrus cloud seeding in a 1.5 × CO2 world are common and which are not. Seeding reduces the net cirrus radiative effect for −1.8 W m−2 in CESM compared with only −0.8 W m−2 in ECHAM. Accordingly, the surface temperature decrease is larger in CESM, counteracting about 70% of the global mean temperature increase due to CO2 and only 30% in ECHAM. While seeding impacts on mean precipitation were addressed in past studies, we are the first to analyze extreme precipitation responses to cirrus seeding. Seeding decreases the frequency of the most extreme precipitation globally. However, the extreme precipitation events occur more frequently in the Sahel and Central America, following the mean precipitation increase due to a northward shift of the Intertropical Convergence Zone. In addition, we use a quadratic climate damage metric to evaluate the amount of CO2-induced damage cirrus seeding can counteract. Seeding decreases the damage by about 50% in ECHAM, and by 85% in CESM over the 21 selected land regions. Climate damage due to CO2 increase is significantly reduced as a result of seeding in all of the considered land regions., Environmental Research Letters, 15 (5), ISSN:1748-9326, ISSN:1748-9318

13 pages, 7 figures, 4 tables, 3 appendixes, supplementary data https://doi.org/10.1016/j.rser.2020.110105, This paper reviews different approaches to modelling the energy transition towards a zero carbon economy. It identifies a number of limitations in current approaches such as a lack of consideration of out-of-equilibrium situations (like an energy transition) and non-linear feedbacks. To tackle those issues, the new open source integrated assessment model pymedeas is introduced, which allows the exploration of the design and planning of appropriate strategies and policies for decarbonizing the energy sector at World and EU level. The main novelty of the new open-source model is that it addresses the energy transition by considering biophysical limits, availability of raw materials, and climate change impacts. This paper showcases the model capabilities through several simulation experiments to explore alternative pathways for the renewable transition. In the selected scenarios of this work, future shortage of fossil fuels is found to be the most influential factor of the simulations system evolution. Changes in efficiency and climate change damages are also important determinants influencing model outcomes, This work was supported by the European Union through the funding of the MEDEAS project under the Horizon 2020 research and innovation programme [grant agreement No 69128], With the funding support of the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000928-S), of the Spanish Research Agency (AEI)

Solomon Hsiang's study, which was recently published in Science, has caused extensive discussion by indicating that future climate change may exert influences on the agricultural yield, labor supply, and energy demand, among others of the United States. Based on the above study, we use an optimized input‐output model to evaluate the economic ripple effect (ERE) of the United States on the world due to climate change under Representative Concentration Pathway 4.5 with different increases in the annual mean temperature (AMT; 1, 1.5, and 2°C) between 2020 and 2100. The results show that if a loss of gross domestic product of 0.88% occurs with a 1°C AMT increase in the United States, the ERE of approximately 0.12% will be generated onto the global gross domestic product; with a 2°C increase, the ERE will triple. The time variation trend of the ERE conforms to the future variations in AMT. The degree of this effect on other regions of the world is closely related to the trade links between the United States and economic aggregates. Among these regions, Canada shows the greatest impact, followed by China. The ERE that China suffers may increase by 4.5 times as the AMT in the United States increases from 1 to 2°C. In cold regions, the benefit from global warming will decrease due to the ERE from other regions, which will inhibit their economic development. This paper aims to provide new perspectives and data‐based support for regions around the world to cope with climate change and to develop policies by studying the ERE behind international trade.

Improving the resilience of the economy in the face of uncertain climate change damages involves irreversible investments to scale up new technologies that are less vulnerable to the effects of climate change. The benefit of having such options includes the avoided welfare cost of diverting consumption to scaling up the new technology after production possibilities have been diminished by climate change impacts. This needs to be balanced against the upfront cost of scaling up a technology that is potentially less productive than incumbent technologies. The paper uses a real options approach to investigate this trade-off, based on numerical simulation of a multi-period model of economic growth and climate change impacts that includes a one-time cost associated with scaling up the alternative technology. The value of the option provided by investment in the more resilient technology depends on the ex-ante volatility of climate change damages, as well as how rapidly climate change degrades the productivity of the economy's established technology. In addition, the size of scale-up cost that leaves the economy indifferent between investing and not investing in the new technology can be used to define the value of early investment in the less climate change–vulnerable technology as a sort of call option.

National Climate Policies : Aiming at the Factor 4 Target by 2050 ? Implications of Cognitive and Ethical Positions. The paper considers how the governments of midsize developed countries could define national strategies to control greenhouse gas emissions, assuming that such strategies are the product of cognitive and ethical choices relating to global climate scenarios and the rule for allocating shares of expected global climate damage to individual States. After evaluating the carbon value linked to each cognitive-ethical configuration, I identify the configurations that justify the target of dividing national emissions by 4 between 1990 and 2050 – a goal known as “ Factor 4”. Lastly, I examine the resulting constraints on the shape of the control trajectory leading to that target., L’article s’intéresse à la manière dont les gouvernements de pays développés de taille moyenne peuvent définir une stratégie nationale de maîtrise des émissions de gaz à effet de serre en supposant qu’une telle stratégie est le produit de choix cognitifs et éthiques touchant aux scénarios climatiques mondiaux et à la règle d’imputation de la part des dommages climatiques planétaires qui revient à chaque État. Au terme d’une évaluation des différentes configurations «cognitivo-éthiques » , sont identifiées celles qui peuvent justifier l’objectif d’une division par 4 des émissions nationales entre 1990 et 2050 (le «Facteur 4 » ), et déterminées les contraintes qui en résultent pour l’allure de la trajectoire de maîtrise des émissions y conduisant., Godard Olivier. Les politiques climatiques nationales : viser le « Facteur 4 » en 2050 ? Implications des positionnements cognitifs et éthiques. In: Économie & prévision, n°208-209, 2016. Politiques de l’environnement. pp. 105-133.

Recent economic research documents a range of adverse welfare consequences from extreme heat stress, including health, labor productivity, and direct consumption disutility impacts. Without rapid adaptation, climate change will increase the burden of heat stress experienced by much of the world’s population in the coming decades. What will the distributional consequences of this added heat stress be, and how might this affect optimal climate policy? Using detailed survey data of household wealth in 690,745 households across 52 countries, this paper finds evidence suggesting that the welfare impacts of added heat stress caused by climate change may be regressive. Specifically, the analysis finds that poorer households tend to be located in hotter locations across and within countries, and poorer individuals are more likely to work in occupations with greater exposure to the elements not only across but also within countries. These findings—combined with the fact that current social cost of carbon estimates do not include climate damages arising from the productivity impacts of heat stress—suggest that optimal climate policy, especially when allowing for declining marginal utility of consumption, involves more stringent abatement than currently suggested, and that redistributive adaptation policies may be required to reduce the mechanical inequities in welfare impacts arising from climate change.

Bogunovic I., Duralija B., Gadze J., Kisic I. (2015): Biostimulant usage for preserving strawberries to climate damages . Hort. Sci., 42: 132–140. Climate changes affect horticultural production through the occurrence of late spring frosts. Therefore plant manage ment is gaining more importance with the aim of improving plant condition. The research deals with the biostimulator containing amino-acids of animal origin (porcine blood) which can be obtained by chemical and/or enzymatic hydrolysis of an organic matrix. During vegetation period different cultivars of strawberries were included in the experiment: Asia, Alba and Clery. The effects of biostimulator on resistance to frost, yields and pomological characteristics were studied at three treatments (0.5 , 1.0 and 1.5 g/plant, and control 0 g/plant). The results showed that all investigated cultivars had a positive response to biostimulant application regarding the frost resistance. Natural frost resistance was the strongest for cv. Clery. Significantly lowest percentage of damage was recorded for cv. Alba at 1.5 g and cvs Clery and Alba at 0.5 g. In the case of late spring frosts and other climatic hazards for growing outdoors cvs Clery and Alba are recommended. All cultivars recorded decreased yields. The difference in yields between cultivars was a consequence of frost damages.

This paper studies the formation of self-enforcing global environmental agreements in a world economy with international trade and two groups of countries that differ with respect to fuel demand and environmental damage. It investigates whether the signatories’ threat to embargo (potential) free riders secures all countries’ participation in the agreement. Resorting to numerical analysis, we find that an embargo may be unnecessary, ineffective or even counterproductive - depending on the degree of asymmetry and other parameters. On some subset of parameters, the embargo stabilizes the otherwise unstable global agreement, but the threat of embargo is not credible. However, in some of these cases credibility can be restored by suitable intra-coalition transfers.

We investigate the formation of global climate agreements (= stable grand climate coalitions) in a model, in which climate policy takes the form of carbon emission taxation and fossil fuel and consumption goods are traded on world markets. We expand the model of Eichner and Pethig (2014) by considering countries that are identical within each of two groups but differ across groups with respect to climate damage or fossil fuel demand. Our numerical analysis suggests that climate damage asymmetry tends to discourage cooperation in the grand coalition. The effects of fuel-demand asymmetry depend on fossil fuel abundance. If fuel is very abundant, the grand coalition fails to be stable independent of the degree of fuel demand asymmetry. If fuel is sufficiently scarce, low degrees of fuel demand asymmetry discourage cooperation whereas higher degrees of asymmetry stabilize the grand coalition.

Emissions of greenhouse gases among other things lead to increasing atmospheric CO2 concentrations, increasing temperatures, changed precipitation patterns and thus multi-factorial changes in the growth environment (1). Primary producers in both terrestrial and aquatic ecosystems and consumers in the food web will experience ecophysiological changes as a consequence of this. To date, only very few truly multi-factorial ecophysiological experiments at the field scale exist. Results from these suggest that the sensitivities of species and ecosystems towards a changing growth environment will be variable (2). Modeling exercises suggest large-scale range shifts of the major biomes of the world (1). The unknown magnitude of future GHG emissions and the complexity of the climate-carbon system induce large uncertainties in the projected changes. A changed climate may result in new interactions and new directions of ecosystem change due to differing adaptive capacities and new species assemblages. Within the framework ‘ecosystem services’ both marketed and non-marketed utilities of the natural environment are formulated (3). Provisioning, cultural, supporting, and regulating ecosystem services have been described. How will these services be affected by the increasing atmospheric GHG concentrations ? How can the changes be expressed in a damage model for LCIA? For the area of protection ‘Natural environment’ both sensitive and robust responses to climate change may be foreseen for different species within ecosystems and between ecosystems. A common metric may thus show high variability. Plural metrics may be needed to adequately describe the variety of different ecosystem services in different regional settings. By evaluation of available data from e.g. global monitoring initiatives of ecosystem services such as UN’s Food and Agriculture Organisation (FAO), UN-REDD (reducing emissions from deforestation and forest degradation in developing countries), and other available sources (e.g. the Global Biodiversity Information Facility), we discuss the selection of indicators for different environmental services from the natural environment, how these can be related to life cycle inventory results for GHG emissions and what would be appropriate metrics for the resulting damage to the area of protection ‘Natural environment’. References [1] Fischlin A, Midgley JT et al 2007. Chapter 4 Ecosystems, their properties, goods and services. In: Climate change 2007. Cambridge, Cambridge University Press, p. 211-272. [2] Mikkelsen TN, Beier C, et al. (2008) Experimental design of multifactor climate change experiments with elevated CO2, warming and drought – the CLIMAITE project. Functional Ecology, 22, 185-195. [3]Millennium Ecosystem Assessment, 2005. Ecosystems and Human Well-being: Biodiversity Synthesis. World Resources Institute, Washington, DC.

This strategic framework serves to guide and support the operational response of the World Bank Group (WBG) to new development challenges posed by global climate change. Unabated, climate change threatens to reverse hard-earned development gains. The poorest countries and communities will suffer the earliest and the most. Yet they depend on actions by other nations, developed and developing. While climate change is an added cost and risk to development, a well-designed and implemented global climate policy can also bring new economic opportunities to developing countries. Climate change demands unprecedented global cooperation involving a concerted action by countries at different development stages supported by "measurable, reportable, and verifiable" transfer of finance and technology to developing countries. Trust of developing countries in equity and fairness of a global climate policy and neutrality of the supporting institutions is critical for such cooperation to succeed. Difficulties with mobilizing resources for achieving the millennium development goals and with agreeing on global agricultural trade underscore the political challenges. The framework will help the WBG maintain the effectiveness of its core mission of supporting growth and poverty reduction. While recognizing added costs and risks of climate change and an evolving global climate policy. The WBG top priority will be to build collaborative relations with developing country partners and provide them customized demand-driven support through its various instruments from financing to technical assistance to constructive advocacy. It will give considerable attention to strengthening resilience of economies and communities to increasing climate risks and adaptation. The operational focus will be on improving knowledge and capacity, including learning by doing. The framework will guide operational programs of WBG entities to support actions whose benefits to developing countries are robust under significant uncertainties about future climate policies and impacts-actions that have "no regrets."

Energy use often is the most significant contributor to the impact category ‘global warming’ in life cycle impact assessment. However, the potential global warming effects on the climate at regional level and consequential effects on the natural environment are not thoroughly described within LCA methodology. The current scientific understanding of the extent of climate change impacts is limited due to the immense complexity of the multi-factorial environmental changes and unknown adaptive capacities at process, species and ecosystem level. In the presentation we argue that the global warming impacts from a product system being studied in an LCA must be seen in context with the changing future background situation. This background situation is among other things affected by e.g. cumulative atmospheric greenhouse gas emissions of yet unknown magnitude. Here, we define climate change damage on the natural environment as climate change driven environmental changes. The man-made environment such as cultivated land, infrastructure and urban areas is not considered. Hypothetical climate change damage functions representing both sensitive and robust responses were analyzed in relation to cumulative green house gas emissions. An attempt was made to link these hypothetical damage functions with current experimental evidence of biological and biogeochemical responses to a changing growth environment. Each LCA stage involves uncertainty due to e.g. choice, modeling, sampling and measurement errors apart from natural variation. Error propagation throughout the stages of the LCA is thus needed. The relative uncertainty (expressed as the coefficient of variation) of the product related emission, of the background situation and of the natural environment responses were compared. It seemed that the overall relative uncertainty of a characterization factor for climate change might be at least 64%-152% indicating a large variability around the unknown mean climate change damage.