Global warming’s local solutions

Climate change is real, and fossil fuels are the principal cause. China must end its reliance on coal and shift to small-scale power generation from renewable sources, argues Jiang Gaoming.

This recent winter was one of the mildest China has ever seen. In many cities in the north, temperatures were much higher than usual and not a single snowflake fell. In east China’s Shandong province, as early as Chinese New Year, ears of wheat were becoming visible and willow trees started to turn green.

Global warming is now causing global concern. Scientists, politicians and more responsible businesspeople are searching for ways to reverse the effects of climate change. Richard Branson, a UK business leader, has put up a US$25 million prize for the first scientist to discover a method to remove one billion tonnes of carbon dioxide from the atmosphere each year.

Scientists are clear on the root cause of global warming: the Industrial Revolution. The Intergovernmental Panel on Climate Change recently concluded that it is at least 90% certain that human emissions of greenhouse gases are warming the planet’s surface. The extraction and burning of vast quantities of coal, gas and oil; destruction of vegetation in poorer regions of the world; and the reduction of the land's ability to absorb and fix carbon dioxide in many places have all caused this rise in greenhouse gases. Atmospheric levels of carbon dioxide have increased from around 290 parts per million (ppm) before the Industrial Revolution, to around 380 ppm today. Of all the factors driving this rise, excessive and inefficient use of fossil fuels is the main culprit.

Take China's electricity industry. First developed in 1882, growth was slow until 1949, at which point capacity was only 1.85 gigawatts (GW), with 4.3 billion kilowatt hours (kWh) generated. But by 1978, China's capacity was the seventh biggest in the world, and by 2000, China had overtaken France, the UK, Canada, Germany, Russian and Japan and was second only to the US in power generation. Eighty percent of this power is currently generated by burning coal. This caused concern in the past because of the acid rain caused by sulphur dioxide released when coal is burnt. And while this is still a problem, greenhouse gases should really cause alarm. It is now clear: fossil fuels are warming the planet.

The best way of stopping global warming is to gradually reduce the amount of coal and other non-renewable energy sources that we burn. The energy sector needs to adopt renewable sources of power: the use of biomass, methane and solid waste as fuel, small-scale hydroelectric projects, solar power, wind power, geothermal energy and wave power. This multi-faceted approach will allow each region, or even each village, to meet its own power needs, with surplus energy fed back into the power grid – and coal left safely in the ground.

Interest in renewable energy sources is also rising. In 2002, renewable energy use around the world was equal to the power generated by two billion tonnes of coal: 13.4% of the power generated by non-renewable sources. Electricity generated from renewable sources accounted for 17.9% of the total. The European Union now aims to increase the percentage of energy from renewable sources from 6% in 1997 to 12% in 2010, 20% in 2020 and 50% in 2050.

But China's power sector still remains in the coal era. Coal accounts for 60% to 70% of all non-renewable fuel sources, while renewable sources only account for 5% of total power generation. In the case of power shortages, the first solutions to be proposed are always increased fossil-fuel burning or large-scale hydroelectric projects (which are renewable, but have been largely abandoned by developed countries due to their huge environmental impact.) Not enough attention is paid to potential solutions, such as burning straw in rural areas, generating hydroelectricity in China’s west and wind and solar power in the northwest.

Annual straw production in villages in north and central China can be as high as 1,000 tonnes: enough to feed 1,000 head of cattle. These cattle would excrete around 25,000 cubic metres of dung, which produces methane that could generate 350,000 kWh of electricity every year – more than a single village can use, leaving a surplus of power. Even including agricultural uses, a village of about 1,000 people uses less than 60,000 kWh of electricity, meaning that methane production from one village could generate enough power for six villages. If a large number of villages were to establish small-scale methane-burning power projects, the excess power could be sold back to the national grid, which could be an important extra income for rural areas. One farm in Anhui is doing just this with the dung from its cows, and generates 22,000 kWh of electricity from up to 1,000 cubic metres of dung each day.

Similarly, there is great potential for small-scale hydroelectricity projects in the west of China. If the government reallocated funding that goes to large hydroelectric projects and used it to encourage business or individual investment in small-scale plants, local power needs would be met and surplus power could be sold back to the grid. Small-scale hydroelectric schemes provide power, protect the environment and offer locals a new source of income. At present, some are strongly advocating a large-scale hydroelectric plant on the Nu River, but they ignore the huge impact it will have on the environment and a world heritage site – for the sake of corporate profits. The government should take note.

In the cities, waste can be used to generate power. The city of Jinan, in east China, has a 3.5 megawatt power plant that burns methane produced by urban waste, generating 70,000 kWh each day. This is a model that future projects seeking to use urban waste can learn from.

China is the world's most populous developing country, and its government has a leading role to play in combating global warming. Investment in power generation should shift from a few large projects to a large number of small-scale power generation schemes, particularly in rural areas. This would not only meet China’s power demands, but also improve the environment, develop rural economies and help fight global warming.


Jiang Gaoming is a professor at the Chinese Academy of Sciences’ Institute of Botany. He is also vice secretary-general of the UNESCO China-MAB (Man and the Biosphere) Committee and a member of the UNESCO MAB Urban Group.