‘China’s irrigation system guilty of massive pollution’

China’s groundwater irrigation system is responsible for polluting the atmosphere with more than 30 megatonnes of carbon dioxide per year – the equivalent of total annual CO2 emissions in New Zealand, new research suggests.
Groundwater used for crop irrigation in China has grown from 10bn cu m in 1950 to more than 100bn cu m today.
China is the largest greenhouse gas emitter in the world, with around 17% of emissions coming from agriculture.
Irrigated agriculture in China produces 70% of the country’s grain. But it takes some 500 litres of water to grow the wheat for one small loaf of bread.
Pollution is caused by the huge amount of energy needed to pump water from underground – in some areas from an average depth of 70m.
This research, published in Environmental Research Letters on Wednesday (13 March) is the first to calculate how much pollution is being created.
The research team at East Anglia University used extensive survey data collected from 366 villages in 11 provinces. They scaled up these results to calculate the emissions created by groundwater pumping across China’s remaining 20 provinces.
The results account for more than 0.5% of China’s total CO2 emissions. By comparison, this is similar to the total amount of CO2 that the whole of New Zealand emits in one year.
The study was released at a time when the drought is creating major concerns of water shortages in England this spring and summer and MPs have renewed calls to move water from wetter regions in North, Scotland and Wales to the parched South.
But DEFRA secretary Caroline Spelman told the BBC that the idea of a national water grid, which is often proposed to deal with the country’s chronic water problems, would be too expensive and logistically difficult to set up.
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