Air pollution is getting so bad in China's major cities that many people are contemplating emigration to escape it.

Others are spending every weekend in the countryside to get a few whiffs of fresh air. Official data showed that 2013 had the most smoggy days in the past 52 years.

Since the beginning of December at least 25 regions and provinces have reported high pollution levels, particularly of PM2.5, which are tiny floating particles measuring 2.5 micrometres or less in diameter.

PM2.5 particles are especially hazardous because they can settle in the lungs and cause respiratory problems. The Ministry of Environmental Protection says there are three major reasons behind the widespread haze - unfavourable weather conditions making it difficult for pollutants to diffuse, motor vehicle exhausts and coal consumption for winter heating.

In an experimental move the authorities in Guizhou have vowed to reduce the number of coalmines in the province by half in the first six months of 2014 to protect the environment, according to Governor Chen Min'er.

This was probably at the urging of Beijing, which tends to try out new policies in one part of the country before spreading them nationwide. This was a lesson learned from the disastrous wholesale imposition of the communes in the 1950s.

Currently there are 1,690 coalmines in Guizhou. The number will be cut to about 800, the provincial government says.

China's announcement on November 23 of an aircraft identification zone in the East China Sea which overlaps a similar zone set up by Japan caused a flurry of alarm, not least because the US staged an immediate provocation by sending two B52 bombers through the zone without prior notification.

Beijing sees a pattern of aggression building up in its offshore waters, with the US using proxies to besiege China. When Japan annexed the Diaoyu/Senkaku Islands - a group of uninhabited rocks claimed by China and Japan - last year then secretary of state Hilary Clinton lost no time warning China that the US is treaty-bound to defend Japan against any military moves against Japanese territory, part of which the islands now were.

The US also has military alliances with the Philippines and South Korea, both of which have maritime disputes with China.

Beijing's stand on the disputes is to "let future generations decide," but the US insists on "ensuring freedom of navigation" in China's offshore waters. That means freedom for US warships to patrol the Taiwan Strait.

The Beijing municipal government plans to relocate about five million residents to neighbouring Hebei Province as part of efforts to control the population, the Economy & Nation Weekly has reported.

Beijing's Mayor Wang Anshun says: "It is time for us to face the conflict between soaring population and limited resources, and to provide solutions to alleviate increasingly serious urban situations such as hazy days and traffic congestion."

In 2005 the State Council passed a development plan for Beijing that estimated the city's population could be kept to about 18 million by 2020. But the figure was already 20 million in 2012.

The city will select several districts and counties for pilot population control programmes. A large number of migrant workers from other parts of China have flocked to Beijing, which has the country's best health-care and education facilities.

These people, most of whom do not have Beijing residence permits, will most likely be the ones relocated.

But this would mean putting a cap on the city's booming construction sector.

A real estate company surprised its staff in the closing days of 2013 by distributing a live goat to each as a year-end bonus in Shiyan, Hubei province, the Chutian Metropolis Daily has reported.

The goats were specially purchased from the Inner Mongolia autonomous region, a company spokesman said.