What Does Global Air Pollution Look Like Over the Last 10 Years?

From 2005 to 2014, scientists at NASA have been monitoring air quality in more than 200 cities around the world to create a global picture of changing air levels over time. The series of maps created from their research shows that there is good news for some areas of Europe, northern America and small parts of Asia.

However, the vast majority of countries in the Asian continent have undergone alarming deteriorations in their air quality in the 10-year investigation. Such work provides clear proof that despite the efforts made by certain nations and the agreement concluded at the COP21 climate change talks in Paris, more action is needed – and it is needed now.

The Good News

Focusing primarily on nitrogen dioxide (NO2), which is the main pollutant expelled by industrial factories and vehicular emissions, the study found that there was good news in parts of Europe. Cities such as London, Madrid and Paris, for example, have shown significant improvement since 2005. However, that good news should be tempered with the admission that Paris introduced emergency measures to improve air quality and reduce transport-related pollution last year after the Eiffel Tower became temporarily invisible as a result of heavy smog.

Elsewhere, northern Italy, which is responsible for much of the country’s industry and economy, also showed vast improvements. The United States as a whole displayed encouraging signs, though 2014 saw a deterioration from previous levels in the 10-year period.

Meanwhile, Japan and Hong Kong were two of the few Asian locations to manifest signs of improved air quality. For the most part, Asian air quality suffered dramatically.

The Bad News

In particular, China and India remain the biggest concerns when it comes to global air pollution. Back in 2011, an alarming study found that Chinese power plants emit as much nitrogen oxides (NOx) as all of the passenger cars in the world. It should be noted that the Chinese have attempted to address the problem and have poured more money and resources into curbing emissions than any other country in the world over the last five years, resulting in something of a new era in Chinese air quality control.

This had led to Chinese cities dropping out of the list of the top 20 most polluted cities in the world completely, which they formerly dominated. However, even with this slight improvement, air quality as a whole has still deteriorated significantly since the monitoring began in 2005.

India, on the other hand, has shown very little in the way of positive signs. It has usurped China’s place as the world’s biggest polluters, with New Delhi topping the list of polluted cities worldwide and 12 others making the top 20 list.

Countries all across the Middle East also demonstrated poorer air quality in 2014 than in 2005 – with the notable exception of Syria. However, that is most likely due to a mass exodus of citizens as a result of the ongoing war than anything else.