Earth Today | Addressing super pollutant threat a must

ONE LOCAL scientist has thrown his support behind the call for countries, including Caribbean small island developing states (SIDS), to give attention to nitrous oxide, a recognised super pollutant that is fuelling global warming while also chipping away at the ozone layer.

Speaking with The Gleaner recently, Dr Adrian Spence, senior research scientist at the International Centre for Environmental and Nuclear Sciences, explained the challenge.

“Nitrous oxide (N2O), a non-carbon dioxide (CO2) greenhouse gas (GHG), is a primary greenhouse gas of concern generally emitted from ecosystems as a by-product of the nitrogen cycle (the flow of nitrogen in the atmosphere, land, aquatic ecosystems, and living organisms), which is crucial for agricultural productivity and food security,” he explained.

“However, human activities such as agriculture, and particularly the application of synthetic, nitrogen-based fertilisers, and energy production, have significantly altered the nitrogen cycle through the release, intended or unintended, of large amounts of N2O to the atmosphere,” Spence added.

“Although this GHG is not released on the scale of CO2, it is of growing concern globally, as N2O has roughly 300 times the global warming potential of CO2 and a lifespan of approximately 112 years in the atmosphere,” he said further.

It is therefore of “paramount importance”, the scientist insisted, that N2O be given the required attention, including from SIDS, who he encouraged to continue to demonstrate leadership in their response to the need for GHG emissions reduction.

“The vulnerability of SIDS to the compounding and cascading impacts of climate change are well established,” he said.

“As SIDS, the agriculture sector is arguably our biggest productive sector; therefore, this provides opportunities for us to continue to demonstrate our leadership in emissions reduction, particularly in the agriculture, forestry, and other land-use sectors,” Spence added.

He has suggested that specific activities could include “precision fertiliser application, improved soil/nutrient management, as well as optimising irrigation and drainage in crop production”.

“In other words, good sustainable agricultural practices are a primary way to balance nitrogen flows, inputs and outputs; and to minimise N2O emissions and its combined environmental impacts,” Spence added.

Increasing levels of GHG emissions, including from N2O, produce a warming effect, which in turn triggers a series of climate impacts – from extreme hurricanes and droughts to rising sea levels and coastal erosion, together with the associated threat to food and water security, as well as to public health.

N2O also affects the ozone layer. It is, in fact, “currently the most significant ozone layer-depleting substance being emitted to the atmosphere”, according to the latest Global Nitrous Oxide Assessment.

“The destructive capacity of today’s nitrous oxide emissions approximately equals the sum of all other current ozone-depleting substance emissions,” that 2024 assessment report of the United Nations Environment Programme and the Food and Agriculture Organisation of the United Nations said.

“The lowest levels of ozone this century and beyond are expected to occur if nitrous oxide emissions continue unabated, and carbon dioxide and methane are abated consistent with climate goals. In such a future, by the end of the century, much of the world’s population could be exposed to ultraviolet levels larger than peak ozone depletion in 1995-2005,” it added.

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