Urban air quality greatly improved by gas use: IGU

The IGU has found urban air quality to be improved by switching to gas

The IGU has found urban air quality to be improved by switching to gas

A case study of four leading cities has confirmed the benefits of converting from coal to natural gas, and has shown the switch can help reduce dangerously high levels of pollutants in the world’s most air polluted places.

The Case Studies in Improving Urban Air Quality report by the International Gas Union (IGU) looked at New York, Beijing, Toronto, and Istanbul, which had all made policy changes to phase out fuels such as coal in an attempt to reduce air pollutants.

New York City was reliant on heavy fuel oil for residential heat and power in 2007, resulting in the city exceeding US Environmental Protection Agency Standards for ozone and fine particles of up to 2.5 micrometres (PM2.5), as well as high levels of sulphur dioxide (SO2) in areas of heavy use of oil.

The city decided to accelerate oil phase-out by developing its natural gas transmission pipelines network, among other measures. By 2013, 30 per cent of heavy fuel-burning building had converted to cleaner fuels – 75 per cent of which had identified natural gas or ultra-low sulphur No. 2 oil as the best option.

An air quality study released in September 2013 found winter concentrations of SO2 had dropped by 69 per cent compared to 2008-09. In 2014 the city had met the EPA standards for PM2.5 and estimated that 780 fewer deaths and 2,000 fewer hospital visits could be attributed to the reduced levels of particulates in the air.

Istanbul had been using poor quality and sulphur heavy coal in the wake of the 1970 oil crisis resulting in SO2 levels exceeding 11 times the current World Health Organisation’s (WHO’s) guidelines.

In response, in 1992 the Istanbul city government banned the burning of lignite coal and began exploiting Turkey’s role as a pipeline thoroughfare with natural gas flowing from Central Asia, Russia, the Caucuses and Iran. The report states that by 1998 half of Istanbul residential heating requirements came from natural gas – in 2012 97 per cent of urbanised territory was supplied by the distribution network.

By 2012 SO2 levels were below the WHO guidelines and while other pollutants stayed high, the report said this was due to increased traffic in Istanbul and without the aggressive fuel switching measures the situation would have been much worse.

The report says in 2004 Ontario opted to eliminate coal from electricity generation to address health concerns in its most populous city, Toronto. Toronto had repeatedly advocated to convert coal-fired generators to natural gas to reduce the estimated 1,700 premature deaths caused by air pollution in the city.

The state opted to increase the use of natural gas, expand its nuclear power and, more recently, invest in renewables. As a result, emissions generated by electricity production dropped to 4 per cent of the total SO2 produced in Ontario from 30 per cent in ’04, 5 per cent of NO2 from 12 per cent, and 7 per cent of particulate matter of up to 10 micrometres to less than one.

The number of premature deaths dropped from 1,700 to 1,300 and hospitalisation linked to poor air quality dropped from 6,000 to 3,550, according to the IGU.

Chinese flag

The report also looked at China – in particular the Beijing-Tianjin-Hebei region – as it has recently begun implementing policies to reduce its reliance on coal. It quotes estimates of 1.2-1.6 million deaths a year in China being attributable to air pollution. The upper end of this would mean one in six deaths in China can be linked with air pollution.

The report estimates 50 per cent of the air pollution is attributable to coal.

In the Beijing-Tianjin-Hebei region, average levels of PM2.5 were found to exceed the WHO recommended levels by 10 times in 2013-2014.

To meet targets set of reducing coal consumption by 57 per cent by 2017, the Chinese government set in action a number of plans. One of these is to build four natural gas power plants to supply the Beijing area and replace the existing coal power plants which will be shut down in 2016. The IGU add the gas power stations will also offer a 2.6 times greater capacity.

The report says it is too early to see the extent of the results from the new measures put in place, but that the initial signs look good. The first half of 2015 resulted in PM2.5 levels decreasing – across the same time period coal consumption was reduced by 8 per cent.

The report concludes that “Recognizing the connections between the health-damaging pollutants and climate damaging pollutants can help maximize the benefits and efficiency of policy actions.

“Each was able to enact a comprehensive set of policies – including promoting fuel switching—to make real progress in reducing the air pollution burden without harming economic growth.”

As the world’s leaders congregate in Paris to decide how best to tackle climate change, the IGU report shows how changing to natural gas as fuel source such can offer emissions reducing benefits when combined with other policies.

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