Once again, as I ponder China’s environmental and social problems, I am confronted by questions of scale. It’s fairly well-established that China’s problems – from oil imports to air pollution to water shortages – are huge, and the government’s reaction has often been to support huge solutions: the 3 Gorges Dam, the South-North Water Diversion project, etc. These are also the sorts of projects that get most often reported in the press. It seems to me that less attention is paid, in the press and probably in the government as well, to smaller scale and simpler technologies that could ultimately play a large role in solving some of China’s problems.
For example, yesterday I learned about a company that produces biomass pellets for rural energy use. Previously biomass (chiefly the crop residues left over after harvesting crops) were the primary energy source in rural areas for heating and cooking. But as rural incomes have increased, people have moved towards purchasing coal briquettes which are cleaner-burning and more convenient than collecting residues. Then the crop residues are simply burned in the field to get rid of them, creating serious air pollution problems in some provinces. Clearly it would make much more sense to find a way to make biomass a more attractive fuel, rather than distributing small amounts of coal over a large area and wasting the biomass. This pelletizing technology does exactly that – it is a village-scale machine that produces small biomass pellets which are much more convenient for home use than loose biomass and burn even more cleanly than coal. Scaling up this technology across China could help improve living conditions and reduce air pollution in rural areas.
Another example of a small-scale technology is rainwater and snow harvesting. This has been implemented in a big way in some southern Indian cities, such as Madras, but it has not really taken hold in Beijing despite the severe water crisis. There are about 50 pilot rainwater harvesting projects in the city, but nothing on the commercial scale. One problem is that Beijing gets almost all of its rain during the summer months, so that there would have to be significant investment in water storage infrastructure. However, if the alternative is to divert water from rivers in southern China, I suspect that this cost would pale in comparison. According to Forum for the Future’s “Greening the Dragon” report, rainwater harvesting in Beijing has the potential to supply about 230 million cubic meters of water each year. This is quite significant relative to the 300 million cubic meters which are currently overdrawn from Beijing’s aquifer each year. Proper pricing for water (Beijing’s water rates are absurdly low for a city so short on water) would also help alleviate the shortage. In short, just because China’s problems are on such a large-scale, it doesn’t necessarily mean that the technical solutions need to be similarly mind-boggling.