Cotton Australia report: Cotton emissions spike by 15 per cent

A six per cent jump in the amount of nitrogen applied to soil per hectare has caused emissions from Australia’s cotton crops to rise sharply.

Greenhouse gas emissions from cotton production increased 15 per cent last year. Photo: supplied

Greenhouse gas emissions from Australian cotton production rose significantly last year, and no date has been set for when the industry’s emissions will be reigned in.

Cotton Australia’s annual sustainability data, released on Monday, showed emissions increased 15 per cent in 2021-22 compared to the previous year.

Cotton Australia chief executive Adam Kay said the industry hadn’t set greenhouse gas reduction targets because it didn’t want to “jump on the carbon neutral bandwagon” without knowing what it could realistically achieve.

“It’s all very well just saying, ‘oh yeah, we’ll be carbon neutral’. But you’ve got to set something that can actually be achieved,” Mr Kay said.

Last year’s emissions increase was due to a six per cent jump in the volume of nitrogen applied to soil per hectare, he said.

In wet years, more nitrogen is typically needed to grow crops as water can leach the nutrient from the soil.

Overall, more than 1.3kg of carbon dioxide equivalent gases were released into the atmosphere for each kilogram of cotton lint produced last year, compared to less than 1.2kg in 2021.

Mr Kay said future technologies would enable cotton farmers to bring their emissions down quickly, but he acknowledged change was “a few years off”.

According to Cotton Australia data, nitrogen fertiliser accounted for about 70 per cent of on-farm greenhouse gas emissions on cotton properties.

Producing nitrogen fertiliser using the traditional Haber Bosch method uses vast quantities of natural gas. But work is underway to replace the gas-powered hydrogen production in the Haber Bosch process with hydrogen produced using renewable energy.

Mr Kay said switching to green hydrogen would potentially halve emissions from fertilisers on-farm.

The Australian government has committed $2 billion to developing green hydrogen technology in Australia, but manufacturing plants are still in early stages.

Green hydrogen was last year estimated to cost three times more to produce than natural gas, but an ANZ report estimated the cost of production could reach parity by the end of the decade.

Cotton Australia was working with scientists to understand what levels of emission reduction were feasible for the industry, Mr Kay said.