Conflicts in the Middle East are bringing down NOx emissions

Two years ago, a study in Science put a detailed analysis behind an idea that had already taken root on a lot of people’s minds: that the unfavourable weather conditions climate change was creating around the world could be related to the world’s growing tendency toward conflicts. The study’s authors weren’t saying that bad weather caused the Second World War but only that it would be legitimate to consider if the changing climate had an adverse impact on human neurophysiology. But setting aside the specifics, the study’s bigger accomplishment was in encouraging a more holistic view of climate change’s impact on humankind.

Now, another study, based on satellite observations and economic data from the World Bank, sets out a karmic inverse of that idea: that conflicts in the Middle East have led to cleaner air over the region.

The satellite data comes from Aura, which NASA launched in 2004 to make qualitative observations of Earth’s atmosphere. One instrument in the apparatus is the Ozone Monitoring Instrument (OMI) that measures variations in the ozone layer, and makes precision measurements of gases detrimental to the atmosphere across a 2,600-km field of view, which lets it log global data almost on a daily basis. And since around 2008, it has found that nitrogen dioxide emissions – released by burning fossil fuels – have been dropping over some cities in the Middle East and over Athens, Greece.

Specifically, OMI found that the density of nitrogen dioxide gas over Cairo, Athens, Tehran and Esfahan (Iran), Baghdad, Tikrit and Samarra (Iraq), the Palestinian territories, Beirut and Tripoli (Lebanon), and Damascus and Aleppo (Syria) bespeak a strong correlation with the shifting political climates in the region. The study describing the findings, published in Science Advances on August 21, 2015, is able to exclude natural variations because the trends were uniformly increasing until 2008-2010 – like in almost all places around world – before deviating significantly.

Since the Arab Spring in 2011 saw a popular uprising starting with Cairo and spreading out into the rest of the Middle East, the GDPs of all the involved economies shrank. Now, the OMI data presents the climatic impact of humanitarian crises and armed conflict – one that long-term projections of the impact of climate change haven’t factored in.

For example, the most significant changes are visible over Greece, Egypt, Iraq, Iran and Syria, as well as over Saudi Arabia and the United Arab Emirates. However, the latter two are discounted from the authors’ analysis for two reasons: the reversal in nitrogen dioxide emission trends over the two countries started before the region started to become turbulent, and began after 2006 and 2008 when the emirates and the kingdom enacted laws to reduce their carbon footprints.

In Egypt, on the other hand, the GDP rose by about 6% per year in 2005-2010 and then fell to 2% per year in 2011-2014. But OMI couldn’t spot any parallel decline in carbon dioxide, so the decline in nitrogen dioxide is being attributed to the reduction of vehicular emissions thanks to petrol becoming more expensive. In Greece, the economic recession caused nitrogen dioxide emissions to fall by 40% in the six years since 2008. In Iran, Tehran’s and Esfahan’s nitrogen dioxide emissions increased at 10% per year in 2005-2010 – as if the 2006 sanctions didn’t happen – but turned down to -4% per year since 2010, when the GDP also saw a sharp downturn by 2 percentage points before turning negative in 2012.

A and B) Tropospheric NO2 column density changes in 10^15 molecules/cm2 (A) between 2005 and 2010 and (B) between 2010 and 2014. Source:
A and B) Tropospheric NO2 column density changes in 10^15 molecules/cm2 (A) between 2005 and 2010 and (B) between 2010 and 2014. Source:

In Iraq, similar correlations between declining GDP and falling nitrogen dioxide emissions are observed over Baghdad, Mosul and Kirkuk, as well as additional declines over the cities of Tikrit and Samarra thanks to incursions by the Islamic State.

As the authors of the Science Advances article write, “such relatively short-term changes cannot be captured by air pollution emission inventories and future projections, including the Representative Concentration Pathways”. The RCPs are a set of projections used by the Intergovernmental Panel for Climate Change based on how much greenhouse gases are enforcing anthropogenic climate change. One of them, RCP4.5, assumes that NOx emissions in the Middle East will be constant from 2005 to 2030, and another, RCP8.5, that they’ll increase at the rate of 2% per year. OMI’s findings suggest these assumptions might be failing reality.

It also reveals how a better estimate of greenhouse gas emissions, as well as country-wise challenges, emerges when ground realities are combined with satellite-logged data. Consider the example of Lebanon, whose carbon dioxide emissions fell by 20% over 2011 and 2012, but whose nitrogen dioxide emissions spiked by 20-30% in 2014. When they probed further, the scientists realised it had to do with the influx of refugees from the Syrian civil war – 1.2 million of them, of which 350,000 fled to Beirut alone.

Featured image credit: magharebia/Flickr, CC BY 2.0.