N₂O: No laughing matter
Following the launch of a deeply concerning new assessment on the alarming increase in emissions from the ‘forgotten greenhouse gas’, Nitrous Oxide – what should be done to avert a global catastrophe?
It is used as an anaesthetic, a rocket propellent and even in whipped cream. It is emitted from our farms and from our factories, and it has been ignored for decades, but Nitrous Oxide (N2O) – better known as ‘laughing gas’ – is no laughing matter for our climate, our ozone layer or our health.
N2O is a potent greenhouse gas and responsible for around 10 per cent of the global warming that we have seen to date. On a tonne for tonne basis, its climate impact is almost 300 times greater than CO2. It is also by far the most significant threat to the ozone-layer today.
Unchecked, our emissions of N2O have increased by 40 per cent since 1980, outpacing and exceeding all of our previous scientific estimates.
Hopefully, we might soon see that change.
The 31 October 2024 saw the launch of the Global N2O Assessment by the Climate and Clean Air Coalition (CCAC), UN Environment Programme (UNEP) and International Nitrogen Management System (INMS), at the 36th Meeting of Parties to the Montreal Protocol in Bangkok, Thailand.
The Montreal Protocol is a global agreement to protect the ozone layer by phasing out the production and consumption of ozone-depleting substances (ODS). And the Global N2O Assessment provides the first comprehensive analysis of N2O’s impact on stratospheric ozone, climate and human health in more than a decade.
It makes for sobering reading, presenting a stark warning if we fail to take collective global action to reduce our N2O emissions. But it also makes clear the significant benefits that ambition mitigation would achieve.
Without action, N2O emissions are on track to increase by a further 30 per cent by 2050. If this happens, within this century, most of the world’s population will be exposed to levels of harmful UV radiation unseen since the late 1990s, when the hole in the ozone layer was at its very worst.
This will result, directly, in rates of skin cancer and cataracts increasing significantly around the world, whilst also damaging the ability of global plant-life to absorb carbon, worsening the effects of climate change.
On the flipside however, an ambitious but feasible 40 per cent reduction in N2O emissions would safeguard the recovery of the ozone layer and, by 2100, avoid climate warming emissions equivalent to 235 billion tonnes of CO2 (around the same as six years’ worth of current emissions from all fossil burning worldwide).
Already by 2050, such a reduction would also secure air quality benefits avoiding roughly 20 million premature deaths globally from co-pollutants such as ammonia and NOx.
To achieve these goals and protect the Montreal Protocol’s legacy as the most successful environmental treaty, countries must consider what role the Protocol will play in controlling this ozone-depleting greenhouse gas.
This is the message that EIA brought to the Global N2O Assessment launch, an event opened by the Assistant Secretary-General of the UN and Deputy Executive Director of UNEP, Elizabeth Maruma Mrema,
Speaking on a discussion panel alongside Undersecretary for Environment of the Philippines, Juan Miguel Cuna and, former Executive Secretary of the Ozone Secretariat, Marco Gonzales, EIA urged Parties to the Montreal Protocol to act, setting out a pathway for them to do so and emphasising the importance that our global ozone treaty leads the way in controlling this potent, ozone-depleting natural gas.
EIA recommended that the Parties first look to industrial emissions of N2O. These emissions–primarily occurring as by-product during adipic and nitric acid production–account for roughly five per cent of total human N2O emissions. Using existing, low-cost abatement technologies, 99 per cent of industrial emissions can be eliminated today. This is the most low-hanging of low-hanging fruits for climate mitigation.
Beyond industrial emissions though, EIA called for the strengthening the patchwork of regulations which currently govern N2O emissions, and the plugging of gaps where no such regulations exist, noting that this requires a coordinated global effort.
With universal ratification, a mandate to act on ODS and an existing precedent of increasing ambition, the Montreal Protocol is the best placed multilateral agreement to achieve this goal.
With this context in mind and drawing on the extensive work already undertaken by the Global N2O Assessment, EIA will continue to advocate for the Montreal Protocol to address this potent super-pollutant.