Energy and climate change最新文献

Japan has formulated a net-zero emissions target by 2050. Existing scenarios consistent with this target generally depend on carbon dioxide removal (CDR). In addition to domestic mitigation actions, the import of low-carbon energy carriers such as hydrogen and synfuels and negative emissions credits are alternative options for achieving net-zero emissions in Japan. Although the potential and costs of these actions depend on global energy system transition characteristics which can potentially be informed by the global integrated assessment models, they are not considered in current national scenario assessments. This study explores diverse options for achieving Japan's net-zero emissions target by 2050 using a national energy system model informed by international energy trade and emission credits costs estimated with a global energy system model. We found that demand-side electrification and approximately 100 Mt-CO₂ per year of CDR implementation, equivalent to approximately 10% of the current national CO₂ emissions, are essential across all net-zero emissions scenarios. Upscaling of domestically generated hydrogen-based alternative fuels and energy demand reduction can avoid further reliance on CDR. While imports of hydrogen-based energy carriers and emission credits are effective options, annual import costs exceed the current cost of fossil fuel imports. In addition, import dependency reaches approximately 50% in the scenario relying on hydrogen imports. This study highlights the importance of considering global trade when developing national net-zero emissions scenarios and describes potential new roles for global models.

Financial incentives, such as carbon credits and feed-in tariffs, are effective policy tools to mobilize renewable energy investment for combating climate change. However, climate and policy uncertainties also induce substantial financial risks to power companies’ investments. A company may view renewable energy as an opportunity or a risky business depending on its perception of how renewable technologies and energy policies evolve. To explore how the diverse response from individual companies affects the power system's adoption of renewables, this study develops an agent-based modeling framework that includes renewable technology advancement, market conditions, and changes in incentive programs in the agents’ decision-making. Power companies (i.e., agents) are assumed profit-driven and have different risk attitudes toward climate and energy policy uncertainty. For illustration, we applied the method to the Texas power system as a case study where a group of agents are randomly generated to represent the power companies’ aggregated behaviors. Agents’ risk attitudes are inferred based on a survey, historical data, and model diagnosis. Results of future scenarios highlight renewable adoption prediction uncertainties and the need to develop holistic modeling approaches to facilitate energy policy and power system planning. This modeling framework creates a flexible representation of the power industry and serves as a building block of our vision toward holistic power system modeling and planning. We discuss future research directions that extend the framework through model coupling for system reliability assessment and improve agent representation regarding risk perception and market dynamics.

We attribute variations in key energy sector indicators across global climate mitigation scenarios to climate ambition, assumptions in background socioeconomic scenarios, differences between models and an unattributed portion that depends on the interaction between these. The scenarios assessed have been generated by Integrated Assessment Models (IAMs) as part of a model intercomparison project exploring the Shared Socio-economic Pathways (SSPs) used by the climate science community. Climate ambition plays the most significant role in explaining many energy-related indicators, particularly those relevant to overall energy supply, the use of fossil fuels, final energy carriers and emissions. The role of socioeconomic background scenarios is more prominent for indicators influenced by population and GDP growth, such as those relating to final energy demand and nuclear energy. Variations across some indicators, including hydro, solar and wind generation, are largely attributable to inter-model differences. Our Shapley–Owen decomposition gives an unexplained residual not due to the average effects of the other factors, highlighting some indicators (such as the use of carbon capture and storage (CCS) for fossil fuels, or adopting hydrogen as an energy carrier) with outlier results for particular ambition-scenario-model combinations. This suggests guidance to policymakers on these indicators is the least robust.

Climate change poses a global challenge, and the electric power sector, as a major greenhouse gas contributor, plays a central role in tackling and curbing its effects. Despite significant research on global and national future pathways, there is a need for further exploration into the application of Representative Concentration Pathways (RCPs) and Shared Socioeconomic Pathways (SSPs) to understand sub-national impacts on the electric power sector. This study employs the Global Change Analysis Model (GCAM-USA) to analyze how climate change mitigation and socioeconomic development interact in the U.S. electric power sector at the state level. We developed four scenarios covering different levels of decarbonization efforts and socioeconomic development. Our research findings reveal a prevailing trend towards a less carbon-intensive U.S. electric sector, propelled by an expanding presence of natural gas and renewable energies in the energy mix. Such capital turnover leads to a significant reduction of overall CO₂ emissions from the electric sector, albeit at a higher lifetime cost in particularly eastern states. The mitigation efforts also lead to overall decreased water withdrawal and increased water consumption in the electric sector, however, disparities in state-level responses are observed. While population growth predominantly shapes electricity generation, unique state-level electrification potential yields indirect population-electricity dynamics. The spatially heterogeneous response suggests complex trade-offs associated with reconciling climate mitigation objectives with local electricity demand and resource constraints. In sum, this research equips policymakers and stakeholders with invaluable insights to formulate mitigation strategies that align with the objective of the U.S. electric sector, both at a national and international level, while also catering to the unique characteristics of each state.

This study assesses the role of geopolitical risk and uncertainty in the degradation of the environment by forming the functions for ecological footprint, CO₂ emissions, and load capacity factor for the period 1990–2019 in India. Besides, the specified function endogenizes economic growth, renewable energy consumption, and natural resource rent as the additional covariates. The use of the autoregressive distributed lag model (ARDL) confirms the long-run relationship between study variables. Further, the dynamic simulations of the autoregressive distributed lag model (DYNARDL) outcomes show that geopolitical risk improves the quality of the environment by reducing the ecological footprint and CO₂ emissions. However, it degrades the environment by reducing the load capacity factor. Furthermore, the uncertainty improves the environmental quality by reducing the CO₂ emissions and ecological footprint, but the reduced load capacity factor due to uncertainty implies the degradation of environmental quality in India. Given these findings, the study proposes different environmental conservation policies.

The facet of sustainability in power generation carries immense importance since the environmental and social aspects of power generation have often been sacrificed for economic gains. It is imperative to develop novel methods that serve the dual purposes of implicating sustainability and catering to the ever-increasing energy demand. This study assesses the potential of municipal solid waste (MSW) to energy production through waste to energy (WTE) technologies and the potential contribution of WTE facilities to meet the peak energy demands of Pakistan. In the current study, two WTE development scenarios, Mass Burn with recyclable materials and Mass Burn without recyclable materials for two cities, Islamabad and Peshawar were considered. The analysis revealed that Mass Burn with recyclable materials has the potential of producing 205 MW and 180 MW of electricity for the selected cities respectively, with positive social, economic, and environmental impact. It was observed that the energy generation from waste helps in the reduction of greenhouse gas (GHG) emissions as compared to landfills which were 65 % for Islamabad and 54 % for Peshawar and also helps in the development of a supply chain system with economic and social benefits.

The urgency of climate change requires a clear understanding of how global technological trends can alter a country's least-cost, low-carbon strategy (net-zero), considering its own advantages in terms of resources, existing knowledge, and energy facilities and converters. This study compares Brazil's least-cost strategies to reach net zero CO₂ emissions by 2050 with strategies based on the technological development patterns suggested by the most recent International Energy Agency's (IEA) net zero report, which are assumed to represent global trends in technology deployment for climate mitigation. Our study is based on the use of an Integrated Assessment Model (IAM) for Brazil. Four different mitigation scenarios are explored. Results show that the IEA technological profile deeply differs from a non-constrained technological deployment for Brazil, particularly in terms of the liquid fuels mix and the time of implementation of electric-driven mobility. In Brazil, biofuels use stand out as the least-cost solution to reach net zero emissions by 2050, mostly due to the use of bioenergy with carbon capture and storage (BECCS), which can slow down fossil fuel phase out in the country. Nevertheless, a hybrid strategy can include the use of ethanol or even hydrogen fuel cells in electric powertrains, though this would require further research and development.

The steel sector represents a growing share of global carbon dioxide (CO₂) emissions and is perceived as a hard-to-abate sector in the drive towards economy-wide decarbonisation. We present a model detailing steel demand and multiple steel production pathways within a larger global multi-regional energy system simulation model, projecting material, energy and emissions flows to 2100. We examine decarbonisation levels and options under different assumptions on climate policy, technologies and steel demand patterns, and study low-carbon options in the production of hydrogen as a steel decarbonisation vector. Global steel demand increases at a decelerated pace compared to the past two decades (+65 % in 2050 compared to 2020), driven by substantial increases in the underlying socio-economic conditions. Climate policies lead to a limited positive feedback effect on steel demand (+21 % in 2050) due a faster equipment turnover and higher electrification, which could be overcompensated by energy saving and material efficiency measures. Increased recycling and strong electrification (up to 63 % of production in 2050) are projected as key levers towards decreasing emissions, made possible thanks to the increasing availability of steel scrap. Strong climate policies would be needed to push the steel sector to decarbonise fully, with electrification, carbon capture, biomass and hydrogen all contributing. Carbon capture would be necessary to reach net-zero emissions in the second half of the century.

This article systematically assesses the status, robustness, and potential impact of greenhouse gas emission reduction targets set by the largest steel producer companies as of mid-2022. The assessment covers the 60 largest steel companies by volume, accounting for more than 60 % of global steel production. Data on company-level greenhouse gas emission reduction targets and emission reduction measures were collected from publicly available documents.

We found that only 30 companies have their own greenhouse gas emission reduction targets of varying timeframes between 2025 and 2060. Even when excluding the 15 Chinese state-owned companies that are under the national 2060 net zero target, 15 companies had no emission reduction targets. Twenty-one companies had long-term targets (2040 or after), of which 18 were net zero emission targets; all but one also had interim targets. If all climate targets identified among the 60 companies are achieved, annual CO₂ emissions for the 60 companies could be reduced by up to 12 % by 2030 and up to 39 % by 2050 in comparison to a baseline scenario. Assuming a gradual increase in global crude steel demand from 1.9 Gt in 2019 to 2.5 Gt in 2050 and assuming similar trends for the rest of the global iron and steel sector as observed for the 60 companies, we estimate that the current ambition of the global iron and steel sector on emission reductions would lead to a reduction of 38 % to 53 % by 2050 from 2019 levels (3.4 GtCO₂ to 1.6–2.1 GtCO₂), or compared to a 32 % to 43 % reduction in a baseline scenario in 2050.

Steel companies are also lagging in setting clear emission reduction plans to achieve their targets. We found that 14 out of the 30 steel producers with targets did not provide an emission reduction plan. The most popular measures amongst the 16 companies that identified at least one measure to achieve their target in their emission reduction plans were hydrogen-based DRI (n = 14), enhanced use of renewable electricity (n = 13) and Carbon Capture Utilisation and Storage (CCU/S) for blast furnaces (n = 9). While it is encouraging that the steel companies have started acting toward long-term deep decarbonisation, our findings suggest that there is a long way ahead and the action needs to be accelerated considerably.

Numerous studies have linked the heterogeneous nature of national technological capabilities to the disparities in country-level low-carbon investment patterns. This study investigates how differences in national and regional technological capabilities can impact the pathway to a global net-zero energy system using an integrated assessment modeling approach. The study begins by developing a novel metric that captures the heterogeneity of national low-carbon technological endowments. The metric is then modeled to explore the regional and global low-carbon investment and CO₂ abatement trends. Modeling results reveal that the heterogeneity of low-carbon technological competencies induces an asymmetry in low-carbon investments across countries and regions. This asymmetry is driven by a low-carbon investment gap created by developing economies with inferior technological capabilities. Conversely, frontier low-carbon technology regions increase their technology deployment efforts to compensate for the investment deficits. The resultant impact of the asymmetry leads to a moderate but non-trivial increase (i.e., 5.1 to 9.3 %) in the policy cost for achieving the net-zero energy target. Insights gleaned from this computational thought experiment reassert the importance of supporting local technological capabilities in the context of global climate mitigation.