LONDON Beijing is one of the most polluted cities in China, according to official statistics.
Every time China hosts a major international event the government has to take extraordinary measures to clean up the air and avoid suffocating its prominent guests in a dangerous choking smog.
On social media, residents ask why the government can clean up for foreigners but can't provide a healthy environment for ordinary citizens who live and work in the city.
Beijing ordered a special anti-smog campaign for China's coming out party at the 2008 Olympic Games and again for the Asia Pacific Economic Cooperation (APEC) summit this week, closing factories and ordering traffic restrictions.
But most of the time, the city's air is terrible. Beijing had 85 bad air days in 2012, equivalent to almost three whole months, when air pollution failed to meet even the government's fairly lax Grade II standard for airborne particles as well as sulfur and nitrogen compounds.
In a ranking of China's 31 provincial-level capital cities, Beijing had the second-worst air quality in the country in 2012. Only Lanzhou, home to several heavy industries and the capital of Gansu province, in central northern China, was more polluted (link.reuters.com/wyr43w).
Pollution is literally killing the inhabitants of China's most polluted cities. During the 1990s, life expectancy in the more polluted northern cities in the north was on average five years lower than in less polluted cities of the south, according to researchers ("Evidence on the impact of sustained exposure to air pollution on life expectancy", 2013).
Climate campaigners blame the problem on China's inefficient coal-fired power plants and argue that the solution is to replace them with cleaner burning natural gas power stations as well as zero-emission sources of electricity such as wind, solar, hydro and nuclear.
Conflating air pollution with global warming is a useful tactic for getting action because it suggests action to prevent the long-term threat of climate change would also yield tangible health benefits in the short term.
But the pollution problem is more complicated. The causes of air pollution are not the same as climate change. China's leaders tend to see them as distinct issues and reducing air pollution is a far more pressing political problem.
HUAI RIVER POLICY
Pollution is worse in northern China than the south. Provincial capitals located to the north of the Huaihe River, which forms the traditional boundary between northern and southern China, generally have far worse pollution than those south of the river.
Northern cities such as Beijing (85), Tianjin (61) and Jinan (42) had far more days with severe air pollution in 2012 than southern metropolises Chongqing (26), Shanghai (23) and Guangzhou (6), according to the National Bureau of Statistics ("China Statistical Yearbook 2013").
Northern China relies much more heavily on coal-fired power generation than the southern half of the country, which has more abundant hydropower. Nonetheless, difference in coal's share of electricity output alone cannot account for the enormous gap in air quality.
Power producers are not the only big source of pollution. During the era of central planning, between 1950 and 1980, China's Communist Party leaders provided free district heating for residents in the colder northern half of China.
Due to budgetary limitations, free heating only extended as far south as the Huaihe River and the Qinling Mountains, which as well as the traditional boundary is roughly as far south as the freezing weather extends, according to researchers at the Massachusetts Institute of Technology ("Winter heating or clean air: unintended impacts of China's Huai River policy", 2009).
Most of the district heating systems, which are still in use today, employ old, inefficient coal-fired boilers to produce steam and hot water. They have few pollution controls and spew soot and mercury as well as sulfur and nitrogen compounds into the urban air.
Northern China also contains most of the most country's energy-intensive industries. Plants are often located in the heart of urban areas. Most have their own coal-fired boilers to generate heat, steam and power rather than taking power from the electricity grid.
Almost all power plants have been fitted with baghouses and scrubbers to capture fly ash and sulfur and nitrogen oxides. District heating and industrial boilers are fitted with much more primitive controls and in many cases none at all.
Cutting the air pollution in northern cities means first and foremost tackling district heating and industrial boilers. In some cases, district heating and industrial systems could be retrofitted with pollution controls or converted to cleaner burning gas.
Natural gas produces half the greenhouse emissions of coal and releases virtually no pollutants such as mercury, sulfur and soot.
In other cases, it might make more sense to switch to electricity from the grid -- even if much of it is still generated by burning coal in central power plants.
Unsurprisingly, State Grid, the giant transmission operator and power producer for most of the country, has been enthusiastically advocating an electrification strategy.
State Grid has an obvious financial interest but the basic idea is sound. Other countries, including Britain, have also adopted electrification as part of their climate strategies.
The difference is that Britain's strategy comes in two parts: (1) electrification of the energy system and (2) decarbonization of electricity production.
So gas-fired central heating and gasoline-filled cars would be replaced by electric heat pumps and plug-in electric vehicles, while at the same time coal-fired power plants would be replaced with wind farms and nuclear power stations.
In China, however, electrification might not be accompanied by decarbonization, or at least not to anything like the same extent.
CLEAN(ER) GRID POWER
China has invested heavily in zero-emission generation, including wind and solar farms. State Grid, as the world’s biggest power system operator, has pioneered the sort of advanced technologies like long-distance ultra-high voltage transmission and giant batteries which will be essential to operating a clean energy system.
However, the majority of grid power will continue to come from coal for the next few decades. In the joint announcement on climate change, issued by the United States and China on Wednesday, China pledged to increase the share of non-fossil fuels in primary energy consumption to around 20 percent by 2030. That still means 80 percent of energy consumption will come from fossil fuels, and, in China, that means mostly coal.
China's leaders could go a long way to solving the urban pollution problem by banning coal-fired district heating and industrial boilers without pollution abatement systems and requiring users to switch to grid power, natural gas, or mandating them to retrofit (expensive) pollution controls.
Electrification would probably also reduce the country's greenhouse gas emissions -- especially if new coal plants are built to ultra-supercritical standards and the country keeps adding wind farms and nuclear power plants.
But while it would dramatically improve air quality it would not cut greenhouse emissions to anywhere near the extent climate campaigners are hoping.
(Editing by David Evans)