2015, Mitra, C., Kurths, J., Donner, R.V.

2016, Zhang, Xianhan, Zhang, Nan, Zhao, Letong, Zhang, Ruihan, Cao, Jinde, Lu, Jianquan, Kurths, Jürgen, Qian, Cheng

Numerous previous studies suggested that people's emotional tendency (ET) towards an issue can often be affected by others. But in some cases, people are unwilling to believe opposite points. This paper aims to study whether people's emotional tendencies (ET) are susceptible with exposures to others' ET concerning a special topic. ET contained in 798,057 pieces of private-information-deleted Chinese Weibo posts are carefully investigated via a revised genetic algorithm, a nonlinear method. Note that nearly all of the posts are closely related to a special topic, the terrible earthquake happen in Japan, 11 March 2011. By conducting statistical analysis including coefficient calculations and hypothesis testing, this study shows that concerning this particular topic, Chinese citizens' first impressions about Japan are solid enough to form their ET and would not be easily altered. Moreover, according to analysis and discussion, we discover that node-to-node impact is exaggerated in some theoretical information diffusion models. Instead it is actually the interaction between nodes' properties and the spread information that matters in the process of information diffusions.

2021, Folke, Carl, Polasky, Stephen, Rockström, Johan, Galaz, Victor, Westley, Frances, Lamont, Michèle, Scheffer, Marten, Österblom, Henrik, Carpenter, Stephen R., Chapin, F. Stuart, Seto, Karen C., Weber, Elke U., Crona, Beatrice I., Daily, Gretchen C., Dasgupta, Partha, Gaffney, Owen, Gordon, Line J., Hoff, Holger, Levin, Simon A., Lubchenco, Jane, Steffen, Will, Walker, Brian H.

The COVID-19 pandemic has exposed an interconnected and tightly coupled globalized world in rapid change. This article sets the scientific stage for understanding and responding to such change for global sustainability and resilient societies. We provide a systemic overview of the current situation where people and nature are dynamically intertwined and embedded in the biosphere, placing shocks and extreme events as part of this dynamic; humanity has become the major force in shaping the future of the Earth system as a whole; and the scale and pace of the human dimension have caused climate change, rapid loss of biodiversity, growing inequalities, and loss of resilience to deal with uncertainty and surprise. Taken together, human actions are challenging the biosphere foundation for a prosperous development of civilizations. The Anthropocene reality—of rising system-wide turbulence—calls for transformative change towards sustainable futures. Emerging technologies, social innovations, broader shifts in cultural repertoires, as well as a diverse portfolio of active stewardship of human actions in support of a resilient biosphere are highlighted as essential parts of such transformations. © 2021, The Author(s).

2008, Rost, S., Gerten, D., Heyder, U.

This study quantifies current and potential future changes in transpiration, evaporation, interception loss and river discharge in response to land use change, irrigation and climate change, by performing several distinct simulations within the consistent hydrology and biosphere modeling framework LPJmL (Lund-Potsdam-Jena managed Land). We distinguished two irrigation simulations: a water limited one in which irrigation was restricted by local renewable water resources (ILIM), and a potential one in which no such limitation was assumed but withdrawals from deep groundwater or remote rivers allowed (IPOT). We found that the effect of historical land use change as compared to potential natural vegetation was pronounced, including a reduction in interception loss and transpiration by 25.9% and 10.6%, respectively, whereas river discharge increased by 6.6% (climate conditions of 1991-2000). Furthermore, we estimated that about 1170km3yr-1 of irrigation water could be withdrawn from local renewable water resources (in ILIM), which resulted in a reduction of river discharge by 1.5%. However, up to 1660km3yr-1 of water withdrawals were required in addition under the assumption that optimal growth of irrigated crops was sustained (IPOT), which resulted in a slight net increase in global river discharge by 2.0% due to return flows. Under the HadCM3 A2 climate and emission scenario, climate change alone will decrease total evapotranspiration by 1.5% and river discharge by 0.9% in 2046-2055 compared to 1991-2000 average due to changes in precipitation patterns, a decrease in global precipitation amount, and the net effect of CO2 fertilization. A doubling of agricultural land in 2046-2055 compared to 1991-2000 average as proposed by the IMAGE land use change scenario will result in a decrease in total evapotranspiration by 2.5% and in an increase in river discharge by 3.9%. That is, the effects of land use change in the future will be comparable in magnitude to the effects of climate change in this particular scenario. On present irrigated areas future water withdrawal will increase especially in regions where climate changes towards warmer and dryer conditions will be pronounced.

2022, Savin, Ivan, Creutzig, Felix, Filatova, Tatiana, Foramitti, Joël, Konc, Théo, Niamir, Leila, Safarzynska, Karolina, van den Bergh, Jeroen

Ambitious climate mitigation policies face social and political resistance. One reason is that existing policies insufficiently capture the diversity of relevant insights from the social sciences about potential policy outcomes. We argue that agent-based models can serve as a powerful tool for integration of elements from different disciplines. Having such a common platform will enable a more complete assessment of climate policies, in terms of criteria like effectiveness, equity and public support. This article is categorized under: Climate Models and Modeling > Knowledge Generation with Models The Carbon Economy and Climate Mitigation > Policies, Instruments, Lifestyles, Behavior Policy and Governance > Multilevel and Transnational Climate Change Governance.

2021, Dasgupta, Shouro, van Maanen, Nicole, Gosling, Simon N., Piontek, Franziska, Otto, Christian, Schleussner, Carl-Friedrich

Background: Although effects on labour is one of the most tangible and attributable climate impact, our quantification of these effects is insufficient and based on weak methodologies. Partly, this gap is due to the inability to resolve different impact channels, such as changes in time allocation (labour supply) and slowdown of work (labour productivity). Explicitly resolving those in a multi-model inter-comparison framework can help to improve estimates of the effects of climate change on labour effectiveness. Methods: In this empirical, multi-model study, we used a large collection of micro-survey data aggregated to subnational regions across the world to estimate new, robust global and regional temperature and wet-bulb globe temperature exposure-response functions (ERFs) for labour supply. We then assessed the uncertainty in existing labour productivity response functions and derived an augmented mean function. Finally, we combined these two dimensions of labour into a single compound metric (effective labour effects). This combined measure allowed us to estimate the effect of future climate change on both the number of hours worked and on the productivity of workers during their working hours under 1·5°C, 2·0°C, and 3·0°C of global warming. We separately analysed low-exposure (indoors or outdoors in the shade) and high-exposure (outdoor in the sun) sectors. Findings: We found differentiated empirical regional and sectoral ERF's for labour supply. Current climate conditions already negatively affect labour effectiveness, particularly in tropical countries. Future climate change will reduce global total labour in the low-exposure sectors by 18 percentage points (range −48·8 to 5·3) under a scenario of 3·0°C warming (24·8 percentage points in the high-exposure sectors). The reductions will be 25·9 percentage points (–48·8 to 2·7) in Africa, 18·6 percentage points (–33·6 to 5·3) in Asia, and 10·4 percentage points (–35·0 to 2·6) in the Americas in the low-exposure sectors. These regional effects are projected to be substantially higher for labour outdoors in full sunlight compared with indoors (or outdoors in the shade) with the average reductions in total labour projected to be 32·8 percentage points (–66·3 to 1·6) in Africa, 25·0 percentage points (–66·3 to 7·0) in Asia, and 16·7 percentage points (–45·5 to 4·4) in the Americas. Interpretation: Both labour supply and productivity are projected to decrease under future climate change in most parts of the world, and particularly in tropical regions. Parts of sub-Saharan Africa, south Asia, and southeast Asia are at highest risk under future warming scenarios. The heterogeneous regional response functions suggest that it is necessary to move away from one-size-fits-all response functions to investigate the climate effect on labour. Our findings imply income and distributional consequences in terms of increased inequality and poverty, especially in low-income countries, where the labour effects are projected to be high. Funding: COST (European Cooperation in Science and Technology). © 2021 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY-NC-ND 4.0 license

2022, Semmler, Willi, Lessmann, Kai, Tahri, Ibrahim, Braga, Joao Paulo, Boros, Endre

This paper analyzes the implications of investors’ short-term oriented asset holding and portfolio decisions (or short-termism), and its consequences on green investments. We adopt a dynamic portfolio model, which contrary to conventional static mean-variance models, allows us to study optimal portfolios for different decision horizons. Our baseline model contains two assets, one asset with fluctuating returns and another asset with a constant risk-free return. The asset with fluctuating returns can arise from fossil-fuel based sectors or from clean energy related sectors. We consider different drivers of short-termism: the discount rate, the nature of discounting (exponential vs. hyperbolic), and the decision horizon of investors itself. We study first the implications of these determinants of short-termism on the portfolio wealth dynamics of the baseline model. We find that portfolio wealth declines faster with a higher discount rate, with hyperbolic discounting, and with shorter decision horizon. We extend our model to include a portfolio of two assets with fluctuating returns. For both model variants, we explore the cases where innovation efforts are spent on fossil fuel or clean energy sources. Detailing dynamic portfolio decisions in such a way may allow us for better pathways to empirical tests and may provide guidance to some online financial decision making.

2013, Schaeffer, Michiel, Gohar, Laila, Kriegler, Elmar, Lowe, Jason, Riahi, Keywan, van Vuuren, Detlef

This paper explores the climate consequences of “delayed near-term action” and “staged accession” scenarios for limiting warming below 2 °C. The stabilization of greenhouse gas concentrations at low levels requires a large-scale transformation of the energy system. Depending on policy choices, there are alternative pathways to reach this objective. An “optimal” path, as emerging from energy-economic modeling, implies immediate action with stringent emission reductions, while the currently proposed international policies translate into reduction delays and higher near-term emissions. In our delayed action scenarios, low stabilization levels need thus to be reached from comparatively high 2030 emission levels. Negative consequences are higher economic cost as explored in accompanying papers and significantly higher mid-term warming, as indicated by a rate of warming 50% higher by the 2040s. By contrast, both mid- and long-term warming are significantly higher in another class of scenarios of staged accession that lets some regions embark on emission reductions, while others follow later, with conservation of carbon-price pathways comparable to the optimal scenarios. Not only is mid-term warming higher in staged accession cases, but the probability to exceed 2 °C in the 21st century increases by a factor of 1.5.

2019, Merganičová, Katarína, Merganič, Ján, Lehtonen, Aleksi, Vacchiano, Giorgio, Ostrogović Sever, Maša Zorana, Augustynczik, Andrey L. D., Grote, Rüdiger, Kyselová, Ina, Mäkelä, Annikki, Yousefpour, Rasoul, Krejza, Jan, Collalti, Alessio, Reyer, Christopher P. O.

Carbon allocation plays a key role in ecosystem dynamics and plant adaptation to changing environmental conditions. Hence, proper description of this process in vegetation models is crucial for the simulations of the impact of climate change on carbon cycling in forests. Here we review how carbon allocation modelling is currently implemented in 31 contrasting models to identify the main gaps compared with our theoretical and empirical understanding of carbon allocation. A hybrid approach based on combining several principles and/or types of carbon allocation modelling prevailed in the examined models, while physiologically more sophisticated approaches were used less often than empirical ones. The analysis revealed that, although the number of carbon allocation studies over the past 10 years has substantially increased, some background processes are still insufficiently understood and some issues in models are frequently poorly represented, oversimplified or even omitted. Hence, current challenges for carbon allocation modelling in forest ecosystems are (i) to overcome remaining limits in process understanding, particularly regarding the impact of disturbances on carbon allocation, accumulation and utilization of nonstructural carbohydrates, and carbon use by symbionts, and (ii) to implement existing knowledge of carbon allocation into defence, regeneration and improved resource uptake in order to better account for changing environmental conditions. © The Author(s) 2019. Published by Oxford University Press.

2014, Stagl, J., Mayr, E., Koch, H., Hattermann, F.F., Huang, S.

For the management of protected areas knowledge about the water regime plays a very important role, in particular in areas with lakes, wetlands, marches or floodplains. The local hydrological conditions depend widely on temporal and spatial variations of the main components of the hydrologic cycle and physiographic conditions on site. To preserve a favourable conservation status under changing climatic conditions park managers require information about potential impacts of climate change in their area. The following chapter provides an overview of how climate change affects the hydrological regimes in Central and Eastern Europe. The hydrological impacts for the protected areas are area-specific and vary from region to region. Generally, an increase in temperature enhances the moisture holding capacity of the atmosphere and thus, leads to an intensification of the hydrological cycle. Key changes in the hydrological system include alterations in the seasonal distribution, magnitude and duration of precipitation and evapotranspiration. This may lead to changes in the water storage, surface runoff, soil moisture and seasonal snow packs as well as to modifications in the mass balance of Central European glaciers. Partly, water resources management can help to counterbalance effects of climate change on stream flow and water availability.