It’s in the bag

It’s no bad thing that buying or binning plastic is becoming the new smoking or drink driving , but too much plastic zealotry could be counter productive. Yes, single use plastic bags  have become an environmental menace and the reuse of plastic items is urgently to be championed but it essential to consider the counterfactuals. 

Even the detested flimsy supermarket bag may do less environmental damage than the seemingly virtuous cotton tote bag. Britain’s Environmental Agency calculated that a cotton bag would have to be used  at least 131 times  before its contribution to global warming fell below that of a single supermarket bag*.

Even a paper bag would have to be used three or four times before being greener than plastic. 

The figures were based on the agency’s finding  that 40% of plastic bags were used more than once. 

Confounding, the agency found that many Britons are  consuming the  sturdier bags  in the same way as the old plastic ones, using them a few times then throwing then away. 

From The Listener

* To sow a crop such as cotton an average of 70 litres of diesel per hectare is burned for cultivation and seeding. This fuel is converted to carbon dioxide at a rate of 2.6kg of carbon dioxide for every litre burnt. Harvesting is also energy intensive with typically more than 20 litres per hectare burned.   Each crop cycle releases 230kg of carbon dioxide into the atmosphere each year.  Pastoral farming with grazing animals has much lower CO2 emissions per hectare than from cultivation. Then the cotton has to be processed using, among other things, bleaches and then woven.