Energy and climate change最新文献

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.

As industries rally toward achieving net zero emissions, hydrogen and hydrogen-based fuels are emerging as key players in decarbonization efforts. Although the primary technology for producing renewable natural gas has been well implemented in the wastewater industry, the “decarbonization based goal setting” is trailing. This perspective assimilates existing literature presented in other contexts to highlight the need for framing the decarbonization dialog by using green hydrogen as a potential pathway for the wastewater industry. Specifically, we note the importance of (a) developing the decarbonization or net zero focus in the wastewater industry, and (b) colocating the wastewater industry with hydrogen production facilities. We also delve into technological, cost, and operational considerations to understand the readiness level of key stakeholders to identify future research and development opportunities for the wastewater hydrogen nexus.

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 study investigates the impact of fossil fuel prices on the regime-switching dynamics of economic policy uncertainty for the global economy. The period of investigation spans 25 years; comprising monthly data for the period of 1998:01 to 2023:03 and, due to its propensity to accommodate shocks, swings and shifts in the data, the technique of analysis employed is the Markov Switching Dynamic Regression. The principal component analysis (PCA) method was used in obtaining a composite index for the fossil fuel prices. The results obtained show evidence of regime-switching behaviour with five (5) times persistence of low to high global economic policy uncertainty. In addition, the study finds significant counter-cyclical and pro-cyclical effects of fossil fuel prices on global economic policy uncertainty; especially under the regime of high uncertainty. These results are consistent with the results for the composite index of fossil fuel prices but with alternate persistence effects. These suggest that policymakers should be concerned in stabilizing fluctuating fossil fuel prices in order to contain its spiralling and uncertain effects on the global economic policy. More so, governments should devise series of low carbon-emission means for home and industrial uses to ultimately reduce the excessive demand for fossil fuel so as to crash its prices in the international market.

Ten Latin American and Caribbean countries have pledged to achieve carbon neutrality since 2019. We assess whether electricity planning in the region has evolved towards reaching this goal. We compare power generation capacity in 2023 with announced plans in 2019. We then estimate committed emissions from existing and planned power plants – emissions that would result from the normal operation of these plants during their typical lifetime – and compare them to emissions from power generation in published IPCC scenarios. We find that fossil fuel planned capacity has decreased by 47 % since 2019, compared to an increase of 24 % of planned renewable power plants. Countries with net-zero pledges tended to cancel more fossil fuel power capacity. But existing plants in the region will emit 6.7 GtCO₂ during their lifespan, and if all planned fossil fuel plants are built, they will add 4.9 GtCO₂. The total 11.6 GtCO₂ emissions exceeds median carbon budgets for 1.5 and 2 °C-consistent IPCC pathways (2.3 and 4.3 GtCO₂). Natural gas power plants are the largest contributor to existing (62 %) and planned (75 %) emissions. We evaluate emissions reduction strategies to achieve carbon budgets. Assuming no new coal plants come into operation, announced gas and oil projects are canceled at the same rate as in the past four years, all fossil fueled plant lifetimes are reduced by 10 years, and all new natural gas displaces existing coal, committed emissions fall by 67 %, meeting the median 2 °C budget, but still falling short of the median 1.5 °C budget. While progress is being made, energy planning in the region is not yet consistent with global climate goals as reflected by IPCC scenarios.

Canada and the United States (US) have both committed to reaching net zero emissions by 2050 but neither have implemented policy sufficient to reach this target. Knowledge of the technical steps to deep decarbonization is needed alongside an understanding of how each country might be similarly and uniquely impacted by a transition to net zero emissions, contingent on specific technology advancements or policy decisions. We use the computable general equilibrium model, gTech, to simulate sixteen net zero scenarios for Canada and the US varying by technology and policy assumptions as part of the energy modelling forum 37 (EMF37) study. We find that both economies similarly continue to grow in all scenarios out to 2050 with the rate of growth largely determined by assumptions on negative emissions technology. Sectoral impacts differ between countries as a result of current emissions and GDP profiles in combination with assumed net zero scenario policy and technology advancements. In the US, we find that efficient use of electricity is a slightly more important predictor of economic outcomes, while Canada's economy is marginally more responsive to cost and performance improvements in carbon capture technologies.

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.

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.