The production, transport and application of pesticides worldwide produces greenhouse gases equivalent to over eight coal-fired power stations – adding further weight to arguments for a move to more nature-friendly alternatives.
Scientists led by Kris Wyckhuys at the Chinese Academy for Agricultural Sciences calculated that the cycle of production and use of insecticides, herbicides and fungicides is responsible for emissions of 136.6 MtCO2 equivalent, with herbicides representing the biggest emitter overall (62.9% of total).
Some of the heaviest impacts are seen in the United States, with nearly 25.7 million barrels of oil used and 2,419 passenger vehicles driven through pesticide use, and Brazil, using 25.5 barrels and 2,395 vehicles, respectively.
“While synthetic pesticides are well-recognized drivers of biodiversity loss that are applied excessively as well as inefficiently, assessments of their carbon emissions are rare,” said the researchers, writing in Nature Food.
“Low-carbon alternatives to pesticide-centred crop protection thus receive scant attention and meagre funding, while their environmental co-benefits remain unrealized.”
Multiple advantages of change
Reducing pesticide applications through integrated pest management (IPM) approaches, combining biological control and agroecological methods, could also increase farm profitability and reduce their dependency on agrochemical companies in a “win-win approach,” they said.
They point to the success of United Nations-backed IPM programmes in the US and Asia, which resulted in significant avoidance of emissions. However, they also note that success in such schemes to date has often proven transient due to “weak policies, ineffective stakeholder engagement or industry meddling.”
Financing opportunities exist
Carbon markets, payments for ecosystem services and natural capital investment can all play a role in financing low-carbon changes on farms, the authors suggested, with shifting a portion of agricultural subsidies towards supporting green innovations particularly important.
Companies working in the IPM sector, such as breeders of natural enemies or start-ups working on robotic weeders or interventions which alter pest behaviour, could benefit from tax breaks or preferential loans, they suggested, with pesticide taxation or crowdfunding also options worth exploring.
Agroecological changes on farms can have dual benefits, they added, with measures such as flower strips and hedgerows improving the carbon sequestration potential of soils while providing habitat to improve natural biological control, and so reduce pesticide applications.
The full journal article is available from Nature Food.
