Supply chains create global benefits from improved vaccine accessibility
Nature Communications | March 21, 2023
Ensuring a more equitable distribution of vaccines worldwide is an effective strategy to control global pandemics and support economic recovery. We analyze the socioeconomic effects - defined as health gains, lockdown-easing effect, and supply-chain rebuilding benefit - of a set of idealized COVID-19 vaccine distribution scenarios. We find that an equitable vaccine distribution across the world would increase global economic benefits by 11.7% ($950 billion per year), compared to a scenario focusing on vaccinating the entire population within vaccine-producing countries first and then distributing vaccines to non-vaccine-producing countries. With limited doses among low-income countries, prioritizing the elderly who are at high risk of dying, together with the key front-line workforce who are at high risk of exposure is projected to be economically beneficial.
How to avoid a local epidemic becoming a global pandemic
Proceedings of the National Academy of Sciences | February 27, 2023
Here, we combine international air travel passenger data with a standard epidemiological model of the initial 3 mo of the COVID-19 pandemic (January through March 2020; toward the end of which the entire world locked down). Our model accurately describes the main features of the actual global development of the pandemic demonstrated by the high degree of coherence between the model and global data. The validated model allows for an exploration of alternative policy efficacies (reducing air travel and/or introducing different degrees of compulsory immigration quarantine upon arrival to a country) in delaying the global spread of SARS-CoV-2 and thus is suggestive of similar efficacy in anticipating the spread of future global disease outbreaks.
The climate impact of high seas shipping
National Science Review | December 08, 2022
Strict carbon emission regulations are set with respect to countries’ territorial seas or shipping activities in exclusive economic zones to meet their climate change commitment under the Paris Agreement. However, no shipping policies on carbon mitigation are proposed for the world’s high seas regions, which results in carbon intensive shipping activities. In this paper, we propose a Geographic-based Emission Estimation Model (GEEM) to estimate shipping GHG emission patterns on high seas regions. The results indicate that annual emissions of carbon dioxide equivalent (CO2-e) in shipping on the high seas reached 211.60 million metric tonnes in 2019, accounting for about one-third of all shipping emissions globally and exceeding annual GHG emissions of countries such as Spain.
The 2022 China report of the Lancet Countdown on health and climate change: leveraging climate actions for healthy ageing
One Earth | October 21, 2022
This report is the third China Lancet Countdown report, led by the Lancet Countdown Regional Centre based in Tsinghua University. With the contributions of 73 experts from 23 leading institutions, both within China and globally, this report tracks progress through 27 indicators in the following five domains: (1) climate change impacts, exposure, and vulnerability; (2) adaptation, planning, and resilience for health; (3) mitigation actions and health co-benefits; (4) economics and finance; and (5) public and political engagement.
The volume of trade-induced cross-border freight transportation has doubled and led to 1.14 gigatons CO2 emissions in 2015
One Earth | October 21, 2022
International freight transport associated with global trade generates significant CO2 emissions. The reduction of these emissions will require international and interregional collaboration. However, which trading partners are responsible for freight transport carbon footprints throughout global value chains remains unclear. Here we link bilateral trade flows of export volume to a multi-regional input-output model to measure CO2 emissions of international freight transport from 1995 to 2015. We find that in 2015, international freight transport generated 1.14 gigatons of CO2, representing 16% of the total emissions associated with international supply chains. Primary contributors were Asia (39%), the European Union (21%) and the United States (13%).
City-level emission peak and drivers in China
Science Bulletin | September 30, 2022
China is playing an increasing role in global climate change mitigation, and local authorities need more city-specific information on the emissions trends and patterns when designing low-carbon policies. This study provides the most comprehensive CO2 emission inventories of 287 Chinese cities from 2001 to 2019. The emission inventories are compiled for 47 economic sectors and include energy-related emissions for 17 types of fossil fuels and process-related emissions from cement production. We further investigate the state of the emission peak in each city and reveal hidden driving forces.
Co-benefits of CO2 emission reduction from China’s clean air actions between 2013-2020
Nature Communications | August 27, 2022
Climate change mitigation measures can yield substantial air quality improvements while emerging clean air measures in developing countries can also lead to CO2 emission mitigation co-benefits by affecting the local energy system. Here, we evaluate the effect of China’s stringent clean air actions on its energy use and CO2 emissions from 2013-2020. We find that widespread phase-out and upgrades of outdated, polluting, and inefficient combustion facilities during clean air actions have promoted the transformation of the country’s energy system. The co-benefits of China’s clean air measures far outweigh the additional CO2 emissions of end-of-pipe devices, realizing a net accumulative reduction of 2.43 Gt CO2 from 2013-2020, exceeding the accumulated CO2 emission increase in China (2.03 Gt CO2) during the same period.
The heterogeneous role of energy policies in the energy transition of Asia–Pacific emerging economies
Nature Energy | May 19, 2022
The Asia–Pacific region (APAC), responsible for more than half of global energy consumption, has enacted a large number of energy policies over the past two decades, but progress on the energy transition remains slow. This study focuses on the aggregate effect of energy policies on the progress towards sustainable targets in 42 emerging economies from 2000 to 2017. We find that energy policies have contributed to improving access to electricity (3.0%), access to clean cooking (3.8%), energy efficiency (1.4%) and renewable electricity capacity (6.9%), respectively. Among different types of energy policy (strategies, laws and regulations), strategies have greater impacts on advancing electrification, clean cooking and renewable electricity capacity than laws and regulations, whereas the laws are more effective for achieving energy efficiency.
Global mitigation efforts cannot neglect emerging emitters
National Science Review | October 19, 2022
International efforts to avoid dangerous climate change have historically focused on reducing energy-related CO2 emissions from countries with either the largest economies (e.g. the EU and the USA) and/or the largest populations (e.g. China and India). However, in recent years, emissions have surged among a different and much less-examined group of countries, raising concerns that a next generation of high-emitting economies will obviate current mitigation targets. Here, we analyse the trends and drivers of emissions in each of the 59 countries where emissions in 2010–2018 grew faster than the global average (excluding China and India), project their emissions under a range of longer-term energy scenarios and estimate the costs of decarbonization pathways.
Life cycle assessment shows that retrofitting coal-fired power plants with fuel cells will substantially reduce greenhouse gas emissions
One Earth | April 15, 2022
China aims to replace 240 TWh CFPPs with fuel cell (FC) technologies by 2050 to achieve carbon-neutrality goals. However, FCs are not emission-free throughout their technology life cycle, and FC effectiveness will vary depending on the CFPP configuration. Despite these uncertainties, a comprehensive evaluation of on-site CFPP-to-FC mitigation potential throughout the entire life cycle remains underexplored. Here, we use a prospective life cycle assessment to evaluate the inclusive mitigation potential of retrofitting 240 TWh CFPPs via four FCs that use wind power/natural gas as feedstocks. Wind-electrolysis hydrogen FCs enable the largest life cycle CO2 reduction, but mining metals for wind turbines reduces PM2.5 and SO2 savings.
Ageing society in developed countries challenges carbon mitigation
Nature Climate Change | March 09, 2022
The impact of senior citizens’ consumption on global carbon mitigation is poorly understood. We find that senior citizens have played a leading role in driving up GHG emissions in the past decade and are on the way to becoming the largest contributor. Considering the greenhouse gas footprint of household consumption across age groups in 32 developed countries, the senior contribution to national total consumption-based emissions increased from 25.2% to 32.7% between 2005 and 2015. Seniors in the United States and Australia have the highest per capita footprint. The increasing carbon footprint of senior citizens will probably drive domestic production yet have limited effects on international carbon leakage. The demographic change poses more challenges in local mitigation and calls for deeper public mitigation efforts.
Drivers of fluctuating embodied carbon emissions in international services trade
One Earth | September 17, 2021
Services trade is becoming increasingly important for global economy, contributing 20% to the global trade in 2019. However, the related emissions have not been paid enough attention. We show that the emissions embodied in services trade have increased at an average annual growth rate of +1.34% and accounted for almost 30% of total global trade emissions from 2010 to 2018. This is mainly driven by increased trade volume and changing trade structure. Services trade in the Global South has higher growth rate and emission intensity. We further analyze the trade pattern of the Global South and divided it into three main trade patterns. Finally, we propose three kinds of specific emission mitigation policies based on the characters of services trade and different trade structures between different regions.
Adaptive CO2 emissions mitigation strategies of global oil refineries in all age groups
One Earth | August 20, 2021
The oil refinery is the world's third-largest stationary emitter of greenhouse gases (GHGs), but the historical mapping of the regional-specific refining industry, their CO2 emission patterns, and mitigation potentials remain understudied. This study develops a plant-level, technical-specific, and time-series global refinery CO2 emission inventory, covering 1,056 refineries from 2000 to 2018. The CO2 emissions of the refinery industry were about 1.3 gigatonnes (Gt) in 2018, representing 4% of the total. If current technical specifications continue, the global refineries will cumulatively emit 16.5 Gt of CO2 during 2020–2030. The refineries vary in operation age, refining configuration structure, and geographical location, leading to the demand for specific mitigation strategies.
Population ageing and deaths attributable to ambient PM2.5 pollution: a global analysis of economic cost
The Lancet Planetary Health | June, 2021
This study examines the interaction between population ageing and the global health cost of deaths attributable to ambient air pollution. Health costs estimated in this study also provide rationale for allocating resources by age groups. Additionally, we used the global exposure mortality model to describe the relationship between pollution exposure and mortality. This study provides updated estimates of the global economic cost of deaths attributable to PM2.5 pollution from 2000 to 2016. Furthermore, our decomposition analysis shows the contribution of population ageing to the growth of health cost attributable to PM2.5 pollution over time. The findings of this study are particularly relevant for pollution control policies in countries that face both high levels of pollution and a rapidly ageing population.
Negligible impacts of early COVID-19 confinement on household carbon footprints in Japan
One Earth | April 23, 2021
Changes in lifestyles and consumption patterns can have major ramifications for GHG emissions. The COVID-19 pandemic catalyzed profound and rapid lifestyle shifts, which makes it a natural experiment for studying the outcomes of such changes for GHG emissions. Despite shifts in the work, socialization, and consumption practices of Japanese households during the early stages of the pandemic (January–May 2020), the overall changes in carbon footprints were negligible. Despite some trade-offs between consumption categories, the general carbon footprint patterns remained similar to 2015–2019 trends and are consistent among age groups. This has implications for decarbonization efforts in that the environmental benefits of changes in consumption patterns might not materialize automatically and be easily reversible.
Policy assessments for the carbon emission flows and sustainability of Bitcoin blockchain operation in China
Nature Communications | April 06, 2021
By investigating carbon emission flows of Bitcoin blockchain operation in China with a simulation-based Bitcoin blockchain carbon emission model, we find that without any policy interventions, the annual energy consumption of the Bitcoin blockchain in China is expected to peak in 2024 at 296.59 Twh and generate 130.50 million metric tons of carbon emission correspondingly. Internationally, this emission output would exceed the total annualized greenhouse gas emission output of the Czech Republic and Qatar. Domestically, it ranks in the top 10 among 182 cities and 42 industrial sectors in China. In this work, we show that moving away from the current punitive carbon tax policy to a site regulation policy which induces changes in the energy consumption structure of the mining activities is more effective in limiting carbon emission of Bitcoin blockchain operation.
Impacts of COVID-19 and fiscal stimuli on global emissions and the Paris Agreement
Nature Climate Change | December 22, 2020
Here, using a global adaptive multiregional input–output model and scenarios of lockdown and fiscal counter measures, we show that global emissions from economic sectors will decrease by 3.9 to 5.6% in 5 years (2020 to 2024) compared with a no-pandemic baseline scenario (business as usual for economic growth and carbon intensity decline). Global economic interdependency via supply chains means that blocking one country’s economic activities causes the emissions of other countries to decrease even without lockdown policies. Supply-chain effects contributed 90.1% of emissions decline from power production in 2020 but only 13.6% of transport sector reductions. Simulations of follow-up fiscal stimuli in 41 major countries increase global 5-yr emissions by −6.6 to 23.2 Gt (−4.7 to 16.4%), depending on the strength and structure of incentives.
Economic footprint of California wildfires in 2018
Nature Sustainability | December 07, 2020
In the western United States, the hazard of wildfire has been increasing for decades. Here, we use a combination of physical, epidemiological and economic models to estimate the economic impacts of California wildfires in 2018, including the value of destroyed and damaged capital, the health costs related to air pollution exposure and indirect losses due to broader economic disruption cascading along with regional and national supply chains. Our results reveal that the majority of economic impacts related to California wildfires may be indirect and often affect industry sectors and locations distant from the fires (for example, 52% of the indirect losses—31% of total losses—in 2018 were outside of California). Our findings and methods provide new information for decision makers tasked with protecting lives and key production sectors and reducing the economic damages of future wildfires.
Consideration of culture is vital if we are to achieve the Sustainable Development Goals
One Earth | February 19, 2021
For a long time, sustainability science and policy design have been rooted in environmental and economic perspectives, leaving the role of culture undervalued. Our analysis contributes to the debate by providing both a conceptual framework and empirical evidence on the relations between cultural values and the achievement of the Sustainable Development Goals (SDGs). Our findings imply the necessity to consider more cultural context and nuances in sustainability science communication and policy design. In particular, sustainable development is suggested to be tailored to, but not be captive of, cultural context.
China’s retrofitting measures in coal-fired power plants bring significant mercury-related health benefits
One Earth | December 18, 2020
China committed to reducing Hg emissions via various retrofitting measures in CFPPs, including the closure of small unit CFPPs, installation of efficient air pollution control devices, and power generation efficiency improvement. However, the effectiveness of these measures on Hg emissions and the related health effects remain poorly understood. In this study we found that Hg emissions have been reduced by 23.51 tons during 2011–2015, which prevented 114 deaths and 30,484.77 points of IQ decrement. Hg mitigation also produces significant mutual health benefits across regions. However, more stringent and effective Hg control measures are urgently needed, and various factors, including CFPP location, population density, and trade-offs between reductions in total Hg and in Hg, must be carefully considered.
Satellite-based estimates of decline and rebound in China’s CO2 emissions during COVID-19 pandemic
Science Advances | December 02, 2020
Here, we instead use satellite observations together with bottom-up information to track the daily dynamics of CO2 emissions during the pandemic. Unlike activity data, our observation-based analysis deploys independent measurement of pollutant concentrations in the atmosphere to correct misrepresentation in the bottom-up data and can provide more detailed insights into spatially explicit changes. Specifically, we use TROPOMI observations of NO2 to deduce 10-day moving averages of NOx and CO2 emissions over China, differentiating emissions by sector and province. Between January and April 2020, China’s CO2 emissions fell by 11.5% compared to the same period in 2019, but emissions have since rebounded to pre-pandemic levels before the coronavirus outbreak at the beginning of January 2020.
Embodied carbon emissions in the supply chains of multinational enterprises
Nature Climate Change | September 07, 2020
Enterprises are at the forefront of climate actions and multinational enterprises (MNEs) engage in foreign direct investment, allowing them substantial influence over the entire supply chain. Yet emissions embodied in the international supply chains of MNEs are poorly known. Here we trace the carbon footprints of foreign affiliates of MNEs and show that the gross volume of global carbon transfer through investment peaked in 2011, mainly driven by the decline in carbon intensity. We propose an investment-based accounting framework to allocate carbon footprints of MNEs to the investing country. Investment-based accounting of emissions could inform targeted and effective climate policies and actions. For instance, some large MNEs play a crucial role in carbon transfer, therefore their originating country should bear more responsibilities of carbon emission reduction as an investor.
Role of export industries on ozone pollution and its precursors in China
Nature Communications | October 30, 2020
Here we show that goods produced in China for foreign markets lead to an increase of domestic non-methane volatile organic compounds (NMVOCs) emissions by 3.5 million tons in 2013; about 13% of the national total or, equivalent to half of emissions from European Union. Production for export increases concentration of NMVOCs (including some carcinogenic species) and peak ozone levels by 20–30% and 6–15% respectively, in the coastal areas. It contributes to an estimated 16,889 (3,839–30,663, 95% CI) premature deaths annually combining the effects of NMVOCs and ozone, but could be reduced by nearly 40% by closing the technology gap between China and EU. Export demand also alters the emission ratios between NMVOCs and nitrogen oxides and hence the ozone chemistry in the east and south coast.
Near-real-time monitoring of global CO2 emissions reveals the effects of the COVID-19 pandemic
Nature Communications | October 14, 2020
Here we present daily estimates of country-level CO2 emissions for different sectors based on near-real-time activity data. The key result is an abrupt 8.8% decrease in global CO2 emissions (−1551 Mt CO2) in the first half of 2020 compared to the same period in 2019. The magnitude of this decrease is larger than during previous economic downturns or World War II. The timing of emissions decreases corresponds to lockdown measures in each country. By July 1st, the pandemic’s effects on global emissions diminished as lockdown restrictions relaxed and some economic activities restarted, especially in China and several European countries, but substantial differences persist between countries, with continuing emission declines in the U.S. where coronavirus cases are still increasing substantially.
Global COVID-19 pandemic demands joint interventions for the suppression of future waves
PNAS | September 28, 2020
By linking seasonality of climate and changing human behavior, we demonstrate that collaboration on global efforts for prompt and intensive intervention is fundamental to coping with future pandemic waves of COVID-19. We propose that this collaboration can be started in locations with typically high population density and international travel, followed by other high-risk locations. We believe this tiered intervention strategy can greatly integrate global efforts and is effective and practical to improve the global emergency response to COVID-19 and many other infectious diseases.
Sharing tableware reduces waste generation, emissions and water consumption in China’s takeaway packaging waste dilemma
Nature Food | September 15, 2020
Here we use a top-down approach with city-level takeaway order data to explore the packaging waste and life-cycle environmental impacts of the takeaway industry in China. The ten most wasteful cities, with just 7% of the population, in terms of per capita waste generation, were responsible for 30% of the country’s takeaway waste, 27–34% of the country’s pollutant emissions and 30% of the country’s water consumption. The results of the scenario simulations show that sharing tableware could reduce waste generation by up to 92%, and environmental emissions and water consumption by more than two-thirds. Such a mechanism provides a potential solution to address the food packaging waste dilemma and a new strategy for promoting sustainable and zero-waste lifestyles.
Weakening aerosol direct radiative effects mitigate climate penalty on Chinese air quality
Nature Climate Change | August 03, 2020
Here we assess how such weakened aerosol direct effects alter the estimates of air pollution and premature mortality in China attributable to mid-century climate change under Representative Concentration Pathway 4.5. We found that weakening aerosol direct effects cause boundary layer changes that facilitate diffusion. This reduces air-pollution exposure (~4% in fine particulate matter) and deaths (13,800 people per year), which largely offset the additional deaths caused by greenhouse gas-dominated warming. These results highlight the benefits of reduced pollutant emissions through weakening aerosol direct effects and underline the potential of pollution control measures to mitigate climate penalties locked in by greenhouse gas emissions.
Critical rare-earth elements mismatch global wind-power ambitions
One Earth | July 24, 2020
Many countries have developed ambitious plans to expand wind power. However, wind turbines heavily rely on rare-earth elements (REs), and it remains unclear whether supply can meet demand. We investigated potential conflicts between RE demand and supply across ten global regions up to 2050 under four widely recognized climate scenarios. We found that RE supply capacity to support ambitious system-wide wind-power development is likely to be hindered by the monopolistic structure of the RE supply chain and intensified geopolitical and environmental constraints, and an 11- to 26-fold increase in production will be necessary to meet ambitious wind-power-expansion targets. To overcome these RE supply challenges, we highlight the importance of facilitating free trade and diversifying RE production via global cooperation.
Global supply-chain effects of COVID-19 control measures
Nature Human Behavior | May 22, 2020
Here, we analyse the supply-chain effects of a set of idealized lockdown scenarios, using the latest global trade modelling framework. We find that supply-chain losses that are related to initial COVID-19 lockdowns are largely dependent on the number of countries imposing restrictions and that losses are more sensitive to the duration of a lockdown than its strictness. However, a longer containment that can eradicate the disease imposes a smaller loss than shorter ones. Earlier, stricter and shorter lockdowns can minimize overall losses. A ‘go-slow’ approach to lifting restrictions may reduce overall damages if it avoids the need for further lockdowns. Regardless of the strategy, the complexity of global supply chains will magnify losses beyond the direct effects of COVID-19. Thus, pandemic control is a public good that requires collective efforts and support to lower-capacity countries.
Production Globalization Makes China’s Exports Cleaner
One Earth | May 22, 2020
This study analyzes the impact of production globalization on the carbon intensity of exports in China while taking trade and spatial heterogeneity into account. We find that production globalization can make China’s exports cleaner. If the degree of global value chain participation (which ranges from 0 to 1) increases by 0.1, the gross carbon intensity of China’s exports will decrease by 11.7%. Our results suggest that developing countries could reduce the carbon intensity of their exports by becoming involved in global production networks if they specialize in relatively low-carbon production stages. However, the global economy has recently been in a deglobalization phase, which could make it more difficult to achieve the Paris Agreement target of 1.5°C.
A psychophysical measurement on subjective well-being and air pollution
Nature Communications | November 29, 2019
The survey techniques usually take long periods to properly match the air pollution characteristics from monitoring stations to each respondent’s SWB at both disaggregated spatial and temporal levels. Here, we used air pollution data to simulate fixed-scene images and psychophysical process to examine the impact from only air pollution on SWB. Findings suggest that under the atmospheric conditions in Beijing, negative emotions occur when PM2.5 (particulate matter with a diameter less than 2.5 µm) increases to approximately 150 AQI (air quality index). The British observers have a stronger negative response under severe air pollution compared with Chinese observers. People from different social groups appear to have different sensitivities to SWB when air quality index exceeds approximately 200 AQI.
The Slowdown in China’s Carbon Emissions Growth in the New Phase of Economic Development
One Earth | October 25, 2019
China’s CO2 emissions have plateaued under its commitment to peaking carbon emissions before 2030 to mitigate global climate change. It is closely linked to the fact that China’s economic development has entered a stage named ‘the new normal’ characterized by more inclusive and sustainable development patterns. This study shows that gains in energy efficiency, deceleration of economic growth, and changes in consumption patterns are the main causes of the deceleration of China’s emissions growth from 2012 to 2017.
Inequality of household consumption and air pollution-related deaths in China
Nature Communications | September 25, 2019
How consumption pattern affects air pollution impacts remains unclear. Here we show, of the 1.08 (0.74–1.42) million premature deaths due to anthropogenic PM2.5 exposure in China in 2012, 20% are related to household direct emissions through fuel use and 24% are related to household indirect emissions embodied in consumption of goods and services. Income is strongly associated with air pollution-related deaths for urban residents in which health impacts are dominated by indirect emissions. Despite a larger and wealthier urban population, the number of deaths related to rural consumption is higher than that related to urban consumption, largely due to direct emissions from solid fuel combustion in rural China. Our results provide quantitative insight to consumption-based accounting of air pollution and related deaths and may inform more effective and equitable clean air policies in China.
Mapping carbon and water networks in the north China urban agglomeration
One Earth | September 20, 2019
Urban sustainability is essential to ensure equality among and the well-being of city citizens, yet most studies focus on individual cities and ignore the vital intercity supply-chain connections. Our research investigates the flows of carbon and water within the Hebei-Beijing-Tianjin urban network in China and reveals a clear imbalance. Goods and services flow from Hebei cities to Beijing and Tianjin, resulting in a local increase in carbon emissions and water loss and an export of economic benefits. Hebei cities are clearly at a disadvantage. The city network approach is essential to ensure sustainable supply-chain management in a future era of urban agglomerations.
The slowdown in global air-pollutant emission growth and driving factors
One Earth | September 20, 2019
Air pollution presents a major threat to human health, the environment and global climate. Identifying the factors—both global and local—that drive emissions of air pollution in any given region is a central challenge for abating emissions and their impacts. This study found that global emissions of many fine particulate matters and precursors continued to grow between 2004 and 2011, but at slower rates due in part to restrictions on industrial processes in China. Regionally, while emissions associated with exports from East Asia to developed countries fell, those associated with exports to developing countries increased. Emissions in all regions are linked by the global supply chain; therefore, international cooperation is essential to address transboundary air pollution and its impacts on human health.
Impacts of climate change on future air quality and human health in China
PNAS | August 12, 2019
More intense extreme events are projected under future climate change. However, the impacts of climate extremes on future air quality and associated health implications are not well recognized and are rarely quantified in China, with an enormous health burden from air pollution. Here, we estimate the climate-driven air pollution mortality in China and find that future climate change is likely to exacerbate air pollution mortality, largely influenced by the more intense extreme events such as stagnation events and heat waves. Our analysis provides quantitative assessments and insights regarding the links between climate extremes, future air quality, and public health, suggesting that extreme weather events may be an important mechanism by which climate change will affect air quality, and especially fine particulate matter.
Impacts of air pollutants from rural Chinese households under the rapid residential energy transition
Nature Communications | July 30, 2019
We evaluate the contribution of rural residential emissions to PM2.5 (particulate matter with an aerodynamic diameter less than 2.5 μm) and the impacts on health and climate. The clean energy transitions result in remarkable reductions in the contributions to ambient PM2.5, avoiding 130,000 (90,000–160,000) premature deaths associated with PM2.5 exposure. The climate forcing associated with this sector declines from 0.057 ± 0.016 W/m2 in 1992 to 0.031 ± 0.008 W/m2 in 2012. Despite this, the large remaining quantities of solid fuels still contributed 14 ± 10 μg/m3 to population-weighted PM2.5 in 2012, which comprises 21 ± 14% of the overall population-weighted PM2.5 from all sources. Rural residential emissions affect not only rural but urban air quality, and the impacts are highly seasonal and location dependent.
The cascade of global trade to large climate forcing over the Tibetan Plateau glaciers
Nature Communications | July 23, 2019
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.
Detection of human influences on temperature seasonality from the nineteenth century
Nature Sustainability | April 22, 2019
It has been widely reported that anthropogenic warming is detectable with high confidence after the 1950s. However, current palaeo climate records suggest an earlier onset of industrial-era warming. Here, we combine observational data, multiproxy palaeo records and climate model simulations for a formal detection and attribution study. Instead of the traditional approach to the annual mean temperature change, we focus on changes in temperature seasonality (that is, the summer-minus-winter temperature difference) from the regional to whole Northern Hemisphere scales. We show that the detectable weakening of temperature seasonality, which started synchronously over the northern mid–high latitudes since the late nineteenth century, can be attributed to anthropogenic forcing.
Data Descriptor: An emissions-socioeconomic inventory of Chinese cities
Scientific Data | February 26, 2019
As the centre of human activity and being under the threat of climate change, cities are considered to be major components in the implementation of climate change mitigation and CO2 emission reduction strategies. Inventories of cities’ emissions serve as the foundation for the analysis of emissions characteristics and policymaking. China is the world’s top energy consumer and CO2 emitter, and it is facing great potential harm from climate change. Consequently, China is taking increasing responsibility in the fight against global climate change. Many energy/emissions control policies have been implemented in China, most of which are designed at the national level. However, cities are at different stages of industrialization and have distinct development pathways; they need specific control policies designed based on their current emissions characteristics.
Emissions are still rising: ramp up the cuts
Nature | December 05, 2018
Representatives of 190 nations gather this week to review progress at the annual United Nations climate talks. They face a daunting reality: carbon dioxide emissions from fossil fuels are rising again. Global CO2 emissions are projected1 to go up in 2018 by more than 2%. In 2017, they increased by 1.6%, having flattened out between 2014 and 2016. The reasons? The use of oil and gas keeps growing, and some countries are still using coal to fuel much of their economic growth (see ‘Rising pressures’). The UN meetings, this year in Katowice, in the heart of Poland’s coalfields, constitute a checkpoint. The Paris climate agreement was adopted in 2015 - when nations signed up to limit global warming to well below 2 °C, and to strive for 1.5 °C. The first formal revisions of national emissions-reduction targets are in 2020.
Decreases in global beer supply due to extreme drought and heat
Nature Plants | October 15, 2018
Beer is the most popular alcoholic beverage in the world by volume consumed, and yields of its main ingredient, barley, decline sharply in periods of extreme drought and heat. Although the frequency and severity of drought and heat extremes increase substantially in range of future climate scenarios by five Earth System Models, the vulnerability of beer supply to such extremes has never been assessed. We couple a process-based crop model (decision support system for agrotechnology transfer) and a global economic model (Global Trade Analysis Project model) to evaluate the effects of concurrent drought and heat extremes projected under a range of future climate scenarios.
Consumption-based greenhouse gas emissions accounting with capital stock change highlights dynamics of fast-developing countries
Nature Communications | September 04, 2018
Few attempts have analyzed the temporal deviation between current emissions and future consumption, which can be explained through changes in capital stock. Here we develop a dynamic model to incorporate capital stock change in consumption-based accounting. The new model is applied using global data for 1995-2009. Our results show that global emissions embodied in consumption determined by the new model are smaller than those obtained from the traditional model. The emissions embodied in global capital stock increased steadily during the period. However, capital plays very different roles in shaping consumption-based emissions for economies with different development characteristics.
A multi-regional input-output table mapping China's economic outputs and interdependencies in 2012
Scientific Data | August 07, 2018
Multi-regional input-output (MRIO) models are one of the most widely used approaches to analyse the economic interdependence between different regions. We utilised the latest socioeconomic datasets to compile a Chinese MRIO table for 2012 based on the modified gravity model. The MRIO table provides inter-regional and inter-sectoral economic flows among 30 economic sectors in China’s 30 regions for 2012. This is the first MRIO table to reflect China’s economic development pattern after the 2008 global financial crisis. The Chinese MRIO table provides a foundation for extensive research on environmental impacts by linking industrial and regional output to energy use, carbon emissions, environmental pollutants, and satellite accounts.
Structural decline in China’s CO2 emissions through transitions in industry and energy systems
Nature Geoscience | July 02, 2018
The prospect of maintaining the continuance of these reductions depends on the relative contributions of different changes in China. Here, we quantitatively evaluate the drivers of the peak and decline of China’s CO2 emissions between 2007 and 2016 using the latest available energy, economic and industry data. We find that slowing economic growth in China has made it easier to reduce emissions. Nevertheless, the decline is largely associated with changes in industrial structure and a decline in the share of coal used for energy. Decreasing energy intensity (energy per unit gross domestic product) and emissions intensity (emissions per unit energy) also contributed to the decline.
City-level climate change mitigation in China
Science Advances | June 27, 2018
As national efforts to reduce CO2 emissions intensify, policy-makers need increasingly specific, subnational information about the sources of CO2 and the potential reductions and economic implications of different possible policies. We present new, city-level estimates of CO2 emissions for 182 Chinese cities, decomposed into 17 different fossil fuels, 46 socioeconomic sectors, and 7 industrial processes. We find that more affluent cities have systematically lower emissions per unit of gross domestic product (GDP), supported by imports from less affluent, industrial cities located nearby. In turn, clusters of industrial cities are supported by nearby centers of coal or oil extraction. Whereas policies directly targeting manufacturing and electric power infrastructure would drastically undermine the GDP of industrial cities, consumption-based policies might allow emission reductions to be subsidized by those with greater ability to pay.
The rise of South–South trade and its effect on global CO2 emissions
Nature Communications | May 14, 2018
Here we show trade among developing nations (i.e., South–South trade) has more than doubled between 2004 and 2011. Some production activities are relocating from China and India to other developing countries, particularly raw materials and intermediate goods production in energy-intensive sectors. In turn, the growth of CO2 emissions embodied in Chinese exports has slowed or reversed, while the emissions embodied in exports from less-developed regions such as Vietnam and Bangladesh have surged. Although China’s emissions may be peaking, ever more complex supply chains are distributing energy-intensive industries and their CO2 emissions throughout the global South. This trend may seriously undermine international efforts to reduce global emissions that increasingly rely on rallying voluntary contributions of more, smaller, and less-developed nations.
China CO2 emission accounts 1997–2015
Scientific Data | January 16, 2018
No annual, officially published emissions data exist for China. The current emissions estimated by academic institutes and scholars exhibit great discrepancies. The gap between the different emissions estimates is approximately equal to the total emissions of the Russian Federation (the 4th highest emitter globally) in 2011. In this study, we constructed the time-series of CO2 emission inventories for China and its 30 provinces. We followed the Intergovernmental Panel on Climate Change (IPCC) emissions accounting method with a territorial administrative scope. The inventories include energy-related emissions (17 fossil fuels in 47 sectors) and process-related emissions (cement production). The first version of our dataset presents emission inventories from 1997 to 2015.
Targeted emission reductions from global super-polluting power plant units
Nature Sustainability | January 08, 2018
There are more than 30,000 biomass- and fossil-fuel-burning power plants now operating worldwide, reflecting a tremendously diverse infrastructure, which ranges in capacity from less than a megawatt to more than a gigawatt. Here, we assess fuel- and region-specific opportunities for reducing undesirable air pollutant emissions using newly developed emission dataset at the level of individual generating units. For example, we find that retiring or installing emission control technologies on units representing 0.8% of the global coal-fired power plant capacity could reduce levels of PM2.5 emissions by 7.7-14.2%. In India and China, retiring coal-fired plants 1.8% and 0.8% of total capacity can reduce total PM2.5 emissions from coal-fired plants by 13.2% and 16.0%, respectively.
Chinese CO2 emission flows have reversed since the global financial crisis
Nature Communication | November 23, 2017
This study seeks to estimate the carbon implications of recent changes in China’s economic development patterns and role in global trade in the post-financial-crisis era. We utilised the latest socioeconomic datasets to compile China’s 2012 multiregional input-output (MRIO) table. Environmentally extended input-output analysis and structural decomposition analysis (SDA) were applied to investigate the driving forces behind changes in CO2 emissions embodied in China’s domestic and foreign trade from 2007 to 2012. Here we show that emission flow patterns have changed greatly in both domestic and foreign trade since the financial crisis.
Trade affects location of air pollution deaths
Nature | March 30, 2017
In a ground-breaking interdisciplinary analysis, we quantify the global links among consumption of goods and services, production of air pollution, atmospheric transport of that pollution, and human mortality due to the pollution. We find that roughly a quarter of air pollution deaths are related to goods produced in one world region for consumption in another. Here we combine four global models to estimate premature mortality caused by fine particulate matter (PM2.5) pollution as a result of atmospheric transport and the production and consumption of goods and services in different world regions.
Unequal household carbon footprints in China
Nature Climate Change | December 19, 2016
Households’ carbon footprints are unequally distributed among the rich and poor due to differences in the scale and patterns of consumption. We present distributional focused carbon footprints for Chinese households and use a carbon-footprint-Gini coefficient to quantify inequalities. We find that in 2012 the urban very rich, comprising 5% of population, induced 19% of the total carbon footprint from household consumption in China, with 6.4 tCO2/cap. The average Chinese household footprint remains comparatively low (1.7 tCO2/cap), while those of the rural population and urban poor, comprising 58% of population, are 0.5–1.6 tCO2/cap.
Global carbon uptake by cement carbonation
Nature Geoscience | November 21, 2016
Calcination of carbonate rocks during the manufacture of cement produced 5% of global CO2emissions from all industrial process and fossil-fuel combustion in 2013. Here, we use new and existing data on cement materials during cement service life, demolition, and secondary use of concrete waste to estimate regional and global CO2 uptake between 1930 and 2013 using an analytical model describing carbonation chemistry. We find that carbonation of cement materials over their life cycle represents a large and growing net sink of CO2, increasing from 0.10 GtC yr−1 in 1998 to 0.25 GtC yr−1 in 2013.
Global climate forcing of aerosols embodied in international trade
Nature Geoscience | September 05, 2016
The role of trade in aerosol climate forcing attributed to different regions has never been quantified. Here, we contrast the direct radiative forcing of aerosols related to regions’ consumption of goods and services against the forcing due to emissions produced in each region. We find that global aerosol radiative forcing due to emissions produced in East Asia is much stronger than the forcing related to goods and services ultimately consumed in that region because of its large net export of emissions-intensive goods.
Take responsibility for electronic-waste disposal
Nature | August 03, 2016
The world is producing ever more electrical and electronic waste. The quantity of dumped computers, telephones, televisions and appliances doubled between 2009 and 2014, to 42 million tonnes per year globally. Much of this waste ends up in the developing world, where regulation is lax. China processed about 70% of the world’s e-waste in 2012; the rest goes to India and other countries in eastern Asia and Africa, including Nigeria. Non-toxic components are valuable, so are more frequently recycled than toxic ones. Disposal plants release toxic materials, volatile organic chemicals and heavy metals, which can harm the environment and human health.
Targeted opportunities for climate–trade dilemma
Nature Climate Change | September 28, 2015
International trade has become the fastest growing driver of global carbon emissions, with large quantities of emissions embodied in exports from emerging economies. International trade with emerging economies poses a dilemma for climate and trade policy: to the extent emerging markets have comparative advantages in manufacturing, such trade is economically efficient and desirable. However, if carbon-intensive manufacturing in emerging countries such as China entails drastically more CO2 emissions than making the same product elsewhere, then trade increases global CO2 emissions.