Collaboration to prevent harmful air pollution from travelling across borders could prevent as many as 1.32 million premature deaths each year by 2040, according to researchers at University of Colorado Boulder and Cardiff University.
According to the study, National climate action can ameliorate, perpetuate, or exacerbate international air pollution inequalities, which was published in Nature Communications, developing countries in particular are reliant on international action to improve air quality, as much of their pollution comes from outside their borders.
The researchers analysed cross-border pollution ‘exchanges’ for 168 countries – focusing in particular on fine particulate matter, known as PM2.5 – and found that coordinated climate action can play a key role in reducing global health inequalities.
‘Inadvertently worse’
“Some climate policies could inadvertently make air pollution inequalities worse, specifically for developing nations that might rely heavily on their neighbours for clean air,” commented Daven Henze, senior author of the new study and professor at the Paul M. Rady Department of Mechanical Engineering at CU Boulder.
“Holistic climate policy should therefore evaluate how dependent a nation is on others’ emissions reductions, how mitigation scenarios reshape air-pollution flows across borders, and whether global efforts are helping or harming equity.”
As the research found, developing countries, particularly in Africa and Asia, are strongly reliant on emissions reduction efforts in other countries to improve their own air quality.
As lead author Omar Nawaz, Cardiff University School of Earth and Environmental Sciences, noted, while studies to date have focused on how “climate action can benefit public health, most research has ignored how this affects the air pollution that travels across international borders and creates inequalities between countries”.
Emissions scenarios
The research team used advanced atmospheric modelling and NASA satellite data to simulate different future emissions scenarios for the year 2040, utilising both this data and a ‘health burden estimation’ to better understand how countries could make an impact through climate policy.
“We were surprised to find that although Asia sees the most total benefits from climate action to its large share of the population, African countries are often the most reliant on external action, with the amount of health benefits they get from climate mitigation abroad increasing in fragmented future scenarios,” Nawaz added.
The study also explored how the balance of pollution flows may shift under different development pathways – in a sustainable socioeconomic development scenario, for example, pollution flowing across the US-Mexico border would substantially decrease, with Mexico experiencing a larger share of the health benefits.
Further study
The researchers plan to continue their work, exploring how climate change alters the weather patterns that transport this pollution, as well as examining other pollutant types, such as ozone, which can travel even farther than PM2.5.
“We thus have follow-up studies in the works to investigate the interplay between climate policies and long-range health co-benefits associated with both species simultaneously,” Henze added. Read more here.
