In major cities across Syria, Iraq, Palestine and Egypt, the levels of nitrogen oxides have dropped by 20-50% since 2010, researchers told the Guardian. Satellite observations show that before 2010, levels had been on a steady and marked rise since the mid 1990s, when monitoring of pollution in the region from space began.
The report, published in the journal Science Advances, argues that the decline is “tragically” linked to political and social upheaval since the time of the Arab spring. It says the dramatic trend reversal is unique to the Middle East.
“We find that geopolitics and armed conflict in the Middle East have really drastically altered air pollution emissions,” said Prof Jos Lelieveld, director at the Max Planck Institute for Chemistry in Germany and lead author on the report.
“From 2005-10 the Middle East has been one of the regions with the fastest growing air pollution emissions. This also occurred in East Asia, but especially in the Middle East. This was related to economic growth in many countries. However it’s the only region in the world where this upward trend of pollution was interrupted around 2010 and then followed by very strong decline.”
Nitrogen oxides are released into the atmosphere, produced by the burning of fossil fuels and to a lesser extent biofuels and agriculture. These have been shown to have a significant impact on air quality and climate change.
The rise of Islamic State has led to a substantial decrease in nitrogen dioxide (NO2) emissions in Baghdad and central Iraq since 2013, with a downward trend beginning two years earlier, the report says. A similar trend reversal is identified in Egypt around the time of the government’s overthrow in 2011. But it attributes drops in other parts of the region, such as Saudi Arabia, Kuwait and the United Arab Emirates, to the introduction of air quality controls.
In Syria, NO2 over Damascus and Aleppo has decreased by 40-50% since 2011, coinciding with the uprising of that year which triggered a bloody civil war that is ongoing. In sharp contrast, the report found a 20-30% increase in NO2 levels over Lebanon in 2014, which it links to the 1.5 million Syrian refugees that have moved into the country, where they make up at least one-fifth of the population.
The analysis stretched as far as Greece, where NO2 levels have been in gradual decline for two decades, but the report shows the trend has accelerated as the economy has declined, citing a drop of 40% over Athens since 2008.
The researchers focused their analysis on data collected by high resolution satellites on cities between 2005 and 2014. They then compared this data to development statistics gathered by the World Bank.
Lelieveld added that the observations have unexpectedly contradicted existing predictions, and that there should be further investment in the use of satellites to monitor the impacts of environmental measures, migration and economic crises. In the Middle East, there are no air quality networks on the ground.
“These findings could not have been predicted and for this reason disagree with emissions scenarios used in the projections of air pollution and climate change in the future. Often these emissions are linked to energy use and CO2 but we find these are simply not good predictors for trends, at least not in the Middle East,” he said.
Air pollution is becoming an increasingly political problem in fast developing countries such as India and China, where the Chinese premier, Li Keqiang, recently vowed to “fight it with all our might”. Physicists believe that air pollutants are killing 4,000 people a day in the country, as a result of heart, lung and stroke problems.
The report says: “Unfortunately, the Middle East is not the only region in the world affected by economic recession and upheaval owing to war, although geopolitical changes appear to be more drastic than elsewhere. It is tragic that some of the observed recent negative NO2 trends are associated with humanitarian catastrophes.”