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Emissions trading scheme (ETS) has been adopted by an increasing number of countries and regions for carbon mitigation, but its actual effect depends on specific program design and institutional context. Before launching the world largest ETS, China experimented with seven independent regional pilots, whose effects are only indirectly explored. Here we provide firm-level evidence of the innovation effect directly from China’s pilot emissions trading, based on latest patenting information and a quasi-experimental design. China’s pilots increase low-carbon innovation of ETS firms by 5–10% without crowding out their other technology innovation. The increase from ETS firms accounts for about 1% increase of the regional low-carbon patents, while a similar increase from large non-ETS firms is also induced by the ETS. Most importantly, the effect is not associated with permit price, auction, or firm characteristics, but is driven by mass-based allowance allocation. A rate-based approach, however, is adopted by China’s national market. It is unclear what opportunities for policy evaluation can be created by various independent Emission Trading Scheme (ETS). Here the authors presented the firm-level evidence of policy effects directly from emissions trading and differential program designs in China and find that China’s pilots largely induced low-carbon innovation of ETS firms without crowding out other technology innovation.

Achieving low-carbon development of the cement industry in the developing countries is fundamental to global emissions abatement, considering the local construction industry’s rapid growth. However, there is currently a lack of systematic and accurate accounting and projection of cement emissions in developing countries, which are characterized with lower basic economic country condition. Here, we provide bottom-up quantifications of emissions from global cement production and reveal a regional shift in the main contributors to global cement CO 2 emissions. The study further explores cement emissions over 2020-2050 that correspond to different housing and infrastructure conditions and emissions mitigation options for all developing countries except China. We find that cement emissions in developing countries except China will reach 1.4-3.8 Gt in 2050 (depending on different industrialization trajectories), compared to their annual emissions of 0.7 Gt in 2018. The optimal combination of low-carbon measures could contribute to reducing annual emissions by around 65% in 2050 and cumulative emissions by around 48% over 2020-2050. The efficient technological paths towards a low carbon future of cement industry vary among the countries and infrastructure scenarios. Our results are essential to understanding future emissions patterns of the cement industry in the developing countries and can inform policies in the cement sector that contribute to meeting the climate targets set out in the Paris Agreement. The rapid deployment of low-carbon measures is urgently needed to reduce cement emissions as cement CO 2 emissions from developing countries will almost deplete the remaining cement emissions budget within climate targets.

The Chinese government has set long-term carbon neutrality and renewable energy (RE) development goals for the power sector. Despite a precipitous decline in the costs of RE technologies, the external costs of renewable intermittency and the massive investments in new RE capacities would increase electricity costs. Here, we develop a power system expansion model to comprehensively evaluate changes in the electricity supply costs over a 30-year transition to carbon neutrality. RE supply curves, operating security constraints, and the characteristics of various generation units are modelled in detail to assess the cost variations accurately. According to our results, approximately 5.8 TW of wind and solar photovoltaic capacity would be required to achieve carbon neutrality in the power system by 2050. The electricity supply costs would increase by 9.6 CNY¢/kWh. The major cost shift would result from the substantial investments in RE capacities, flexible generation resources, and network expansion. This study indicates that approximately 5.8 TW of wind and solar photovoltaic capacity would be required to achieve carbon neutrality in China’s power system by 2050. The electricity supply costs would increase by 19.9% or 9.6 CNY¢/kWh.

Recognizing that bioenergy with carbon capture and storage (BECCS) may still take years to mature, this study focuses on another photosynthesis-based, negative-carbon technology that is readier to implement in China: biomass intermediate pyrolysis poly-generation (BIPP). Here we find that a BIPP system can be profitable without subsidies, while its national deployment could contribute to a 61% reduction of carbon emissions per unit of gross domestic product in 2030 compared to 2005 and result additionally in a reduction in air pollutant emissions. With 73% of national crop residues used between 2020 and 2030, the cumulative greenhouse gas (GHG) reduction could reach up to 8620 Mt CO 2 -eq by 2050, contributing 13–31% of the global GHG emission reduction goal for BECCS, and nearly 4555 Mt more than that projected for BECCS alone in China. Thus, China’s BIPP deployment could have an important influence on achieving both national and global GHG emissions reduction targets. BIPP with biochar sequestration is a ready-to-implement negative emission technology in China. Here, the authors show that its national deployment could contribute to a 61% reduction of carbon emissions per GDP in 2030 compared to 2005, and contribute 13–31% of the global biomass-based negative emission goal by 2050.

Many countries have undertaken large and high-profile payment-for-ecosystem-services (PES) programs to sustain the use of their natural resources. Nevertheless, few studies have comprehensively examined the impacts of existing PES programs. Grassland Ecological Compensation Policy (GECP) is one of the few pastorally focused PES programs with large investments and long duration, which aim to improve grassland quality and increase herder income. Here we present empirical evidence of the effects of GECP on grassland quality and herder income. Through a thorough and in-depth econometric analysis of remote sensing and household survey data, we find that, although GECP improves grassland quality (albeit to only a small extent) and has a large positive effect on income, it exacerbates existing income inequality among herders within their local communities. The analysis demonstrates that the program has induced herders to change their livestock production behavior. Heterogeneity analysis emphasizes the importance of making sure the programs are flexible and are adapted to local resource circumstances. China has introduced a payment-for-ecosytsem-services program called GECP which is focused on pastoral communities in grassland areas. Here, the authors combine remote sensing and household survey data to find small improvement in grassland quality and a significant positive effects on the income of herders.

The social cost of carbon dioxide (SC-CO 2 ) measures the monetized value of the damages to society caused by an incremental metric tonne of CO 2 emissions and is a key metric informing climate policy. Used by governments and other decision-makers in benefit–cost analysis for over a decade, SC-CO 2 estimates draw on climate science, economics, demography and other disciplines. However, a 2017 report by the US National Academies of Sciences, Engineering, and Medicine 1 (NASEM) highlighted that current SC-CO 2 estimates no longer reflect the latest research. The report provided a series of recommendations for improving the scientific basis, transparency and uncertainty characterization of SC-CO 2 estimates. Here we show that improved probabilistic socioeconomic projections, climate models, damage functions, and discounting methods that collectively reflect theoretically consistent valuation of risk, substantially increase estimates of the SC-CO 2 . Our preferred mean SC-CO 2 estimate is $185 per tonne of CO 2 ($44–$413 per tCO 2 : 5%–95% range, 2020 US dollars) at a near-term risk-free discount rate of 2%, a value 3.6 times higher than the US government’s current value of $51 per tCO 2 . Our estimates incorporate updated scientific understanding throughout all components of SC-CO 2 estimation in the new open-source Greenhouse Gas Impact Value Estimator (GIVE) model, in a manner fully responsive to the near-term NASEM recommendations. Our higher SC-CO 2 values, compared with estimates currently used in policy evaluation, substantially increase the estimated benefits of greenhouse gas mitigation and thereby increase the expected net benefits of more stringent climate policies. Coupling advances in socioeconomic projections, climate models, damage functions and discounting methods yields an estimate of the social cost of carbon of US$185 per tonne of CO 2 —triple the widely used value published by the US government.

While marine kelp forests have provided valuable ecosystem services for millennia, the global ecological and economic value of those services is largely unresolved. Kelp forests are diminishing in many regions worldwide, and efforts to manage these ecosystems are hindered without accurate estimates of the value of the services that kelp forests provide to human societies. Here, we present a global estimate of the ecological and economic potential of three key ecosystem services - fisheries production, nutrient cycling, and carbon removal provided by six major forest forming kelp genera ( Ecklonia, Laminaria, Lessonia, Macrocystis, Nereocystis , and Saccharina ). Each of these genera creates a potential value of between $64,400 and $147,100/hectare each year. Collectively, they generate between $465 and $562 billion/year worldwide, with an average of $500 billion. These values are primarily driven by fisheries production (mean $29,900, 904 Kg/Ha/year) and nitrogen removal ($73,800, 657 Kg N/Ha/year), though kelp forests are also estimated to sequester 4.91 megatons of carbon from the atmosphere/year highlighting their potential as blue carbon systems for climate change mitigation. These findings highlight the ecological and economic value of kelp forests to society and will facilitate better informed marine management and conservation decisions. By combining fisheries, nutrient, and carbon cycling data, this synthesis suggests that marine kelp forests, a dominant but often undescribed habitat, provide services with a potential value of $111,000/ha/year and a global yearly value of $500 billion.

The production of materials is an important source of greenhouse gas emissions. To reduce emissions, policies aim to enhance material efficiency and the circular economy, but our understanding of the dynamics of material-related greenhouse gas emissions is limited. Here, I quantify the greenhouse gas emissions from material production and the carbon footprint of materials in industries that are the first users of materials, and in final consumption, using a multiregional input–output model of the global economy and the hypothetical extraction method. From 1995 to 2015, greenhouse gas emissions from just material production increased by 120%, with 11 billion tons of CO 2 -equivalent emitted in 2015. As a proportion of global emissions, material production rose from 15 to 23%. China accounted for 75% of the growth. In terms of the first use of materials, two-fifths of the carbon footprint of materials is attributed to construction, and two-fifths to the manufacturing of machinery, vehicles and other durable products. Overall, the replacement of existing or formation of new capital stocks now accounts for 60% of material-related emissions. Policies that address the rapidly growing capital stocks in emerging economies therefore offer the best prospect for emission reductions from material efficiency. Investment in capital formation between 1995 and 2015 has driven a 120% increase in the greenhouse gas emissions from material production, according to a multiregional input–output model of the global economy.

Extreme heat undermines the working capacity of individuals, resulting in lower productivity, and thus economic output. Here we analyse the present and future economic damages due to reduced labour productivity caused by extreme heat in Europe. For the analysis of current impacts, we focused on heatwaves occurring in four recent anomalously hot years (2003, 2010, 2015, and 2018) and compared our findings to the historical period 1981–2010. In the selected years, the total estimated damages attributed to heatwaves amounted to 0.3–0.5% of European gross domestic product (GDP). However, the identified losses were largely heterogeneous across space, consistently showing GDP impacts beyond 1% in more vulnerable regions. Future projections indicate that by 2060 impacts might increase in Europe by a factor of almost five compared to the historical period 1981–2010 if no further mitigation or adaptation actions are taken, suggesting the presence of more pronounced effects in the regions where these damages are already acute. Heatwaves are becoming increasingly frequent and more intense, causing severe economic impacts through reduced labour productivity. Here, the authors show that economic damages in Europe exceed 1% of the GDP in vulnerable areas, which might increase by a factor of almost five in the medium term without climate action.

Aquaculture is a rapidly growing food production technology, but there are significant concerns related to its environmental impact and adverse social effects. We examine aquaculture outcomes in a three pillars of sustainability framework by analyzing data collected using the Aquaculture Performance Indicators. Using this approach, comparable data has been collected for 57 aquaculture systems worldwide on 88 metrics that measure social, economic, or environmental outcomes. We first examine the relationships among the three pillars of sustainability and then analyze performance in the three pillars by technology and species. The results show that economic, social, and environmental outcomes are, on average, mutually reinforced in global aquaculture systems. However, the analysis also shows significant variation in the degree of sustainability in different aquaculture systems, and weak performance of some production systems in some dimensions provides opportunity for innovative policy measures and investment to further align sustainability objectives.