The costs and benefits of climate change mitigation are known to be distributed unevenly across time and space, while their intergenerational distribution across nations has not been evaluated. Here, ...we analyze the lifetime costs and benefits of climate change mitigation by age cohorts across countries under the Paris Agreement. Our results show that the age cohorts born prior to 1960 generally experience a net reduction in lifetime gross domestic product per capita. Age cohorts born after 1990 will gain net benefits from climate change mitigation in most lower income countries. However, no age cohorts enjoy net benefits regardless of the birth year in many higher income countries. Furthermore, the cost-benefit disparity among old and young age cohorts is expected to widen over time. Particularly, lower income countries are expected to have much larger cost-benefit disparity between the young and the old. Our findings highlight the challenges in building consensus for equitable climate policy among nations and generations.
The transition to low-carbon electricity is crucial for meeting global climate goals. However, given the uneven spatial distribution and temporal variability of renewable resources, balancing the ...supply and demand of electricity will be challenging when relying on close to 100% shares of renewable energy. Here, we use an electricity planning model with hourly supply-demand projections and high-resolution renewable resource maps, to examine whether transcontinental power pools reliably meet the growing global demand for renewable electricity and reduce the system cost. If all suitable sites for renewable energy are available for development, transcontinental trade in electricity reduces the annual system cost of electricity in 2050 by 5-52% across six transcontinental power pools compared to no electricity trade. Under land constraints, if only the global top 10% of suitable renewable energy sites are available, then without international trade, renewables are unable to meet 12% of global demand in 2050. Introducing transcontinental power pools with the same land constraints, however, enables renewables to meet 100% of future electricity demand, while also reducing costs by up to 23% across power pools. Our results highlight the benefits of expanding regional transmission networks in highly decarbonized but land-constrained future electricity systems.
A growing body of literature discusses the CO2 emissions of cities. Still, little is known about black carbon (BC), a short-lived warming agent. Identifying the drivers of urban BC emissions is ...crucial for targeting cleanup efforts. A consumption-based approach enables all emissions to be allocated along the production chain to the product and place of final consumption, whereas a production approach attributes emissions to the place where goods and services are produced. In this study, we calculate the production-based and consumption-based emissions in 2012 in four Chinese megacities: Beijing, Shanghai, Tianjin and Chongqing. The results show that capital formation is the largest contributor, accounting for 37%–69% of consumption-based emissions. Approximately 44% of BC emissions related to goods consumed in Chongqing and more than 60% for Beijing, Shanghai and Tianjin occur outside of the city boundary. The large gap between consumption and production-based emissions can be attributed to the great difference in embodied emission intensities. Therefore, collaborative efforts to reduce emission intensity can be effective in mitigating climate change for megacities as either producers or consumers.
•We calculate consumption-based black carbon emissions for four Chinese megacities.•Capital formation is the largest contributor to consumption-based emissions.•44%–66% of consumption-based emissions are embodied in imports.•Large net imported emissions are attributable to a relatively lower emission intensity.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
Chiral materials are an ideal playground for exploring the relation between symmetry, relativistic effects and electronic transport. For instance, chiral organic molecules have been intensively ...studied to electrically generate spin-polarized currents in the last decade, but their poor electronic conductivity limits their potential for applications. Conversely, chiral inorganic materials such as tellurium have excellent electrical conductivity, but their potential for enabling the electrical control of spin polarization in devices remains unclear. Here, we demonstrate the all-electrical generation, manipulation and detection of spin polarization in chiral single-crystalline tellurium nanowires. By recording a large (up to 7%) and chirality-dependent unidirectional magnetoresistance, we show that the orientation of the electrically generated spin polarization is determined by the nanowire handedness and uniquely follows the current direction, while its magnitude can be manipulated by an electrostatic gate. Our results pave the way for the development of magnet-free chirality-based spintronic devices.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Reverse Watson–Crick DNA with parallel‐strand orientation (ps DNA) has been constructed. Pyrrolo‐dC (PyrdC) nucleosides with phenyl and pyridinyl residues linked to the 6 position of the ...pyrrolo2,3‐dpyrimidine base have been incorporated in 12‐ and 25‐mer oligonucleotide duplexes and utilized as silver‐ion binding sites. Thermal‐stability studies on the parallel DNA strands demonstrated extremely strong silver‐ion binding and strongly enhanced duplex stability. Stoichiometric UV and fluorescence titration experiments verified that a single 2pyPyrdC–2pyPyrdC pair captures two silver ions in ps DNA. A structure for the PyrdC silver‐ion base pair that aligns 7‐deazapurine bases head‐to‐tail instead of head‐to‐head, as suggested for canonical DNA, is proposed. The silver DNA double helix represents the first example of a ps DNA structure built up of bidentate and tridentate reverse Watson–Crick base pairs stabilized by a dinuclear silver‐mediated PyrdC pair.
Base pairs in reverse mode: The highly fluorescent pyrrolo2,3‐dpyrimidine 2'‐deoxyribonucleoside (2pyPyrdC) forms a tremendously stable silver‐mediated base pair that incorporates two silver ions in the parallel‐stranded double helix (see figure; dA=2'‐deoxyadenosine, dC=2'‐deoxycytidine, dG=2'‐deoxyguanosine, dT=2'‐deoxythymidine, meiCd=5‐methyl‐2'‐deoxyisocytidine, iGd=2'‐deoxyisoguanosine, Tm=melting temperature).
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Environmental problems, associated with climate change and air pollution, have become increasingly serious for China in recent years, which have aroused great domestic and international concerns. To ...mitigate these problems with great efforts, the Chinese government has implemented the Environmental Protection Tax Law in the whole country since the beginning of 2018. Although the new tax law is perceived as an aggressive policy that tends to establish a taxation system for promoting air pollution control, evaluations of its effectiveness are insufficient and urgently needed for China. Using a multiregion multisector Computable General Equilibrium model, we, for the first time, quantify the impacts of this 'pollution tax' policy on modulating air pollutants emissions. Our analysis shows that current tax policy is generally able to reduce many short-lived air pollutants emissions (e.g. SO2, NOX, TSP, PM10, PM2.5, CO, VOCs, OC, NH3 and BC), but the significant effects only happen in regions with large economic scale (i.e. Guangdong, Shandong and Zhejiang provinces) and in sectors with high emission intensity (i.e. the electric power and nonmetal manufacturing sectors). However, at the national level, the overall effect of the current policy on air pollution mitigation is relatively small, less than 2% compared to a business-as-usual scenario. Large emission reduction potentials exist if the tax increases. Therefore, a more ambitious tax policy is urgently needed in order to achieve China's air pollution mitigation target of 2020. We also find that in China for implementing any pollution tax policies, the rate of decline in CO2 emissions is much larger than those of short-lived pollutants, which indicates a huge co-benefit on global climate change mitigation.
Air pollution, a threat to air quality and human health, has attracted ever-increasing attention in recent years. In addition to having local influence, air pollutants can also travel the globe via ...atmospheric circulation and international trade. Black carbon (BC), emitted from incomplete combustion, is a unique but representative particulate pollutant. This study tracked down the BC aerosol and its direct radiative forcing to the emission sources and final consumers using the global chemical transport model (MOZART-4), the rapid radiative transfer model for general circulation simulations (RRTM), and a multiregional input–output analysis (MRIO). BC was physically transported (i.e., atmospheric transport) from western to eastern countries in the midlatitude westerlies, but its magnitude is near an order of magnitude higher if the virtual flow embodied in international trade is considered. The transboundary effects on East and South Asia by other regions increased from about 3% (physical transport only) to 10% when considering both physical and virtual transport. The influence efficiency on East Asia was also large because of the comparatively large emission intensity and emission-intensive exports (e.g., machinery and equipment). The radiative forcing in Africa imposed by consumption from Europe, North America, and East Asia (0.01 Wm–2) was even larger than the total forcing in North America. Understanding the supply chain and incorporating both atmospheric and virtual transport may improve multilateral cooperation on air pollutant mitigation both domestically and internationally.
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IJS, KILJ, NUK, PNG, UL, UM
Black carbon (BC) aerosols constitute unique and important anthropogenic climate forcers that potentially accelerate the retreat of glaciers over the Himalayas and Tibetan Plateau (HTP). Here we show ...that a large amount of BC emissions produced in India and China-a region of BC emissions to which the HTP is more vulnerable compared with other regions-are related to the consumption of goods and services in the USA and Europe through international trade. These processes lead to a virtual transport pathway of BC from distant regions to the HTP glaciers. From a consumption perspective, the contribution from India to the HTP glaciers shows a rapid increasing trend while the contributions from the USA, Europe, and China decreased over the last decade. International trade aggravates the BC pollution over the HTP glaciers and may cause significant climate change there. Global efforts toward reducing the cascading of BC emissions to Asia, especially the Indian subcontinent, are urgently needed.
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