The use of shale gas is commonly considered as a low-cost option for meeting ambitious climate policy targets. This article explores global and country-specific effects of increasing global shale gas exploitation on the energy markets, on greenhouse gas emissions, and on mitigation costs. The global techno-economic partial equilibrium model POLES (Prospective Outlook on Long-term Energy Systems) is employed to compare policies which limit global warming to 2°C and baseline scenarios when the availability of shale gas is either high or low. According to the simulation results, a high availability of shale gas has rather small effects on the costs of meeting climate targets in the medium and long term. In the long term, a higher availability of shale gas increases baseline emissions of greenhouse gases for most countries and for the world, and leads to higher compliance costs for most, but not all, countries. Allowing for global trading of emission certificates does not alter these general results. In sum, these findings cast doubt on shale gas’s potential as a low-cost option for meeting ambitious global climate targets.
POLICY RELEVANCE
Many countries with a large shale gas resource base consider the expansion of local shale gas extraction as an option to reduce their GHG emissions. The findings in this article imply that a higher availability of shale gas in these countries might actually increase emissions and mitigation costs for these countries and also for the world. An increase in shale gas extraction may spur a switch from coal to gas electricity generation, thus lowering emissions. At the global level and for many countries, though, this effect is more than offset by a crowding out of renewable and nuclear energy carriers, and by lower energy prices, leading to higher emissions and higher mitigation costs in turn. These findings would warrant a re-evaluation of the climate strategy in most countries relying on the exploitation of shale gas to meet their climate targets. 相似文献
To assess the potential impacts of the US withdrawal from the Paris Agreement, this study applied GCAM-TU (an updated version of the Global Change Assessment Model) to simulate global and regional emission pathways of energy-related CO2, which show that US emissions in 2100 would reduce to ?2.4?Gt, ?0.7?Gt and ?0.2?Gt under scenarios of RCP2.6, RCP3.7 and RCP4.5, respectively. Two unfavourable policy scenarios were designed, assuming a temporary delay and a complete stop for US mitigation actions after 2015. Simulations by the Model for the Assessment of Greenhouse-gas Induced Climate Change (MAGICC) indicate that the temperature increase by 2100 would rise by 0.081°C–0.161°C compared to the three original RCPs (Representative Concentration Pathways) if US emissions were kept at their 2015 levels until 2100. The probability of staying below 2°C would decrease by 6–9% even if the US resumes mitigation efforts for achieving its Nationally Determined Contribution (NDC) target after 2025. It is estimated by GCAM-TU that, without US participation, increased reduction efforts are required for the rest of the world, including developing countries, in order to achieve the 2°C goal, resulting in 18% higher global cumulative mitigation costs from 2015 to 2100.Key policy insights
President Trump’s climate policies, including planned withdrawal from the Paris Agreement, cast a shadow on international climate actions, and would lower the likelihood of achieving the 2°C target.
To meet the 2°C target without the US means increased reduction efforts and mitigation costs for the rest of the world, and considerable economic burdens for major developing areas.
Active state-, city- and enterprise-level powers should be supported to keep the emission reduction gap from further widening even with reduced mitigation efforts from the US federal government.
We developed a least-cost path analysis algorithm that satisfies a slope threshold condition in hilly terrain. The new algorithm uses an expanding moving-window to explore a combination of cells that satisfy an elevation threshold condition and then supplements this by executing cut and fill operations when there are obstacle cells between source and destination cells. Cut and fill factors regarding the difference in the actual elevation and revised elevation are considered and a least-cost path is analyzed after calculating the accumulated travel cost to the destination point. After applying the developed algorithm to synthetic and real-world data, the least accumulated travel cost from the source point can then be calculated for all cells on the raster surface by considering various slope thresholds, moving-window sizes and raster data resolutions. This algorithm can be implemented as a useful tool in GIS software as well as engineering design software utilized in the construction and mining industries. 相似文献