Air pollution and global solutions

Air pollution is a leading cause of death globally. Efforts to clean the air will not only save lives but contribute to addressing broader environmental and socioeconomic challenges.

The United States currently has modest levels of air pollution after decades of clean air actions. Dr Colette Heald, an atmospheric chemist at the Massachusetts Institute of Technology, speaks to Nature Geoscience about air pollution control in the US, and the challenges and opportunities faced under global environmental change.

China has made progress in improving air quality, but current levels of air pollution still have great health impacts. Dr Qiang Zhang, an atmospheric chemist at Tsinghua University, speaks to Nature Geoscience about air pollution control in China, and the challenges and opportunities faced under global environmental change.

India is currently one of the most polluted regions in the world. Dr Chandra Venkataraman, an expert in climate change and air pollution at the Indian Institute of Technology Bombay, speaks to Nature Geoscience about challenges and opportunities facing air pollution control in India.

Africa’s worsening air pollution has received too little attention. We argue that actions are needed in energy transition management, transport emission regulation and waste management to protect Africa’s air quality.

The CLOUD experiment provides important insights into new particle formation in different atmospheric environments.

Analyses of atmospheric nitrogen chemistry in Beijing’s air pollution during the COVID-19 lockdown suggest an increasing role of nighttime nitrogen chemistry in haze formation above the city.

The global population is increasingly exposed to daily landscape fire-sourced air pollution but there are socioeconomic disparities, with this pollution four times higher in low-income countries than in high-income countries during the period 2000–2019.

Measurements suggest that emissions from biomass burning drive the rapid growth of particles from nanoscale into sizes relevant for haze formation during the night in Delhi.

Ground- and satellite-based air pollution data from 2000 to 2022 quantify the contribution of wildfire smoke to stagnation or reversal in PM_2.5 concentration trends, showing that this contribution will grow as the climate continues to warm.

Measurements show that night-time production of atmospheric nitrate radicals increased in China but decreased in the European Union and the United States from 2014 to 2019. This suggests the increasing contribution of night-time atmospheric oxidation in China to air pollution.

The exact contribution of food systems to air pollution is unknown. On the basis of the European Commission’s EDGAR-FOOD database, a global emission inventory of air pollutants from the food systems, this study quantifies historic emissions of major pollutant compounds at each stage of the food supply chain at country level.

Global chemical transport simulations reveal an ozone photochemistry regime where the uptake of hydroperoxyl radicals onto aerosol particles dominates ozone production.

Recurring climatic patterns can be used to predict severe winter particulate air pollution over North China, according to an analysis of wintertime particulate concentrations and atmospheric circulation.

Fine particulate aerosols and black carbon emissions from fossil fuel combustion, attributed to traffic, are a major contributor to poor air quality in Nairobi, Kenya, according to a year-long time series of black carbon concentration and radiocarbon composition in particulate matter.

The formation of secondary organic aerosol in Chinese megacities is dominated by the condensation of anthropogenic organic vapours, according to measurements across three urbanized regions.

Fine particulate aerosols sampled around the Arabian Peninsula predominantly originate from anthropogenic pollution and constitute one of the leading health risk factors in the region, according to shipborne sampling and numerical atmospheric chemistry modelling.

A quantification of PM_2.5 pollution finds that mortality risk lies disproportionately within low-income households, and that addressing their indoor air pollution sources can avert more absolute deaths, yet wealthier individuals are more responsible for the emissions.

Secondary air pollution events are enhanced in the Yangtze River delta, China, due to the interaction of long-range transport and aerosol–boundary layer feedback, according to a combination of observations and simulations of haze events from 2013 to 2018.

Half of the reduced visibility due to haze formation in cities in India is attributed to local emission of gas-phase hydrochloric acid from waste-burning and industry, according to measurements of particulate matter and thermodynamic modelling.

Sustained emission reductions have altered the prevailing regime for ozone formation over China, weakening the trade-off in pollution control between aerosols and ozone, according to analyses of ozone pollution chemistry between 2013 and 2021.

Reactive nitrogen (Nr) contributes strongly to PM_2.5 air pollution in Europe. Here, authors identify diverse Nr control pathways for Europe depending on emission and pollution formation and a priority of NH₃ control when costs are considered.

Deposition of sulfate and nitrate in China has declined more slowly than emissions of their precursors, sulfur dioxide and nitrogen oxides, according to a combination of emissions inventory and air quality and statistical modelling.

Spatial planning and policy could guide China’s livestock sector towards reducing human exposure to ammonia—provided that 5–10 billion animals are relocated across the region.

Reduction of ammonia emissions may be effective in reducing the nitrate component of fine particulate matter air pollution across the North China Plain, according to the simulation of nitrate trends using the GEOS-Chem atmospheric chemistry model.

Population growth and dietary changes affect ammonia emissions from agriculture and the concentration of particulate matter in the atmosphere. This study quantifies the adverse health impacts associated with these processes in China using a mechanistic model of particulate matter formation and transport. It also compares them with direct health impacts of changing diets upon premature death from food-related diseases.

Energy intensity improvement, scale structure adjustment and electrification measures in major industrial sectors can substantially and simultaneously reduce CO₂, NO_x, SO₂ and particulate matter emissions.

Observations confirm that cleaning up fine particulate matter in the North China Plain has exacerbated ozone pollution, suggesting that both NO_x and VOC emissions need to be reduced to improve air quality.

Nitrogen deposition in China has been almost constant over the past decade, as decreasing wet deposition has balanced increasing dry deposition, according to analyses of extensive datasets on wet and dry nitrogen depositions in China.

Climate model simulations suggest that reducing aerosol pollution enhances the cooling effects of afforestation, which could partially counteract the warming effect of air quality measures.

Cloud droplet number concentrations are often assumed to depend linearly on atmospheric aerosols (in log–log space). Here the authors show that this relationship is instead sigmoid, which delays additional warming due to air pollution mitigation by 20–30 years in heavily polluted regions.

U.S. federal climate policies can reduce air pollutant emissions and associated health impacts from fine particulate matter. However, near-term CO₂ reductions alone are insufficient to address racial/ethnic disparities in pollution exposure.

How a nuclear power phase-out may affect air pollution, climate and health in the future is up for debate. Here the authors assess impacts of a nuclear phase-out in the United States on ground-level ozone and fine particulate matter (PM_2.5).

In contrast to the overall recovery of stratospheric ozone, ozone depletion in the tropical lower stratosphere has been ongoing over recent years. Here the authors show that currently unregulated halogenated ozone-depleting very short-lived substances play a key role in this ongoing depletion.

Most research on the impacts of food loss and waste (FLW) looks at food security, resource use and climate. Based on product-level FLW data and an NH₃ emission inventory, atmospheric chemistry simulations reveal the potential of FLW reductions in mitigating PM_2.5 air pollution and nitrogen deposition.

More than 15 million cases of respiratory and cardiovascular infections could be prevented, saving $2 billion USD each year in human health costs by protecting indigenous lands in the Brazilian Amazon, suggest estimates of PM2.5 health impacts between 2010 and 2019.

Emission controls avoided some 870,000 deaths in China between 2002 and 2017 but further air quality improvements need energy-climate policies and changed economic structure, according to index decomposition analysis and chemical transport models.

Climate mitigation policies often provide health co-benefits. Analysis of individual power plants under future climate–energy policy scenarios shows reducing air pollution-related deaths does not automatically align with emission reduction policies and that policy design needs to consider public health.

Overexposure to ozone compromises crop yields, yet accurate estimates of such impact in Asia have been hindered by limited empirical data. This study assesses relative yield losses of three main crops in Japan, China, and South Korea through O₃ exposure–response relationships based on monitoring data and experiment-based sensitivities.

Air pollution harms health but rises with economic activity, which aids health. This study uses long-range Saharan dust to isolate impacts, finding a significant rise in Sub-Saharan infant mortality from particulate pollution.