Impacts of air pollutants from rural Chinese households under the rapid residential energy transition
Nature communications | July 30, 2019
Rural residential energy consumption in China is experiencing a rapid transition towards clean energy, nevertheless, solid fuel combustion remains an important emission source. 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
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.
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
Traditional consumption-based greenhouse gas emissions accounting attributed the gap between consumption-based and production-based emissions to international trade. Yet 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 can be used to analyse the production and consumption structure of provincial economies and the inter-regional trade pattern within China, as well as function as a tool for both national and regional economic planning. The Chinese MRIO table also 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
As part of the Paris Agreement, China pledged to peak its CO2 emissions by 2030. In retrospect, the commitment may have been fulfilled as it was being made—China’s emissions peaked in 2013 at a level of 9.53 gigatons of CO2, and have declined in each year from 2014 to 2016. However, 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. This is particularly true in China, a large and economically diverse country that has rapidly industrialized and urbanized and that has pledged under the Paris Agreement that its emissions will peak by 2030. 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
Economic globalization and concomitant growth in international trade since the late 1990s have profoundly reorganized global production activities and related CO2 emissions. Here we show trade among developing nations (i.e., South–South trade) has more than doubled between 2004 and 2011, which reflects a new phase of globalization. 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
China is the world’s top energy consumer and CO2 emitter, accounting for 30% of global emissions. Compiling an accurate accounting of China’s CO2 emissions is the first step in implementing reduction policies. However, 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 — such as iron, steel, copper and gold — 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.