The distinguished climate scientist, Professor Myles Allen, addressed a large audience via a video link at the Manx Museum on Monday, talking about agricultural emissions.

He was speaking at the invitation of the Manx NFU and the size of the turnout of members of the farming community demonstrated their commitment to understanding best practice when it comes to farming in a sustainable way. The event was also attended by politicians, including the Chief Minister Alf Cannan, Environment, Food and Agriculture Minister Clare Barber, and Treasury Minister Dr Alex Allanson, along with representatives from DEFA and the Government’s Climate Change Transformation Team.

Manx NFU president Ean Parsons introduced Professor Allen, saying: ‘I had the privilege, just before Covid in 2020, to listen to him live at a conference and he left a lasting impression on me.

‘At the Manx NFU we firmly believe that agriculture on the Isle of Man is part of the solution, not the problem, to climate change.’

Chris Kneale, who is chairman of the Manx NFU’s environment and land committee, also spoke, referencing the series of carbon audit reports carried out on a number of farms across the island which were commissioned by the Manx NFU with support from DEFA.

He said: ‘After this initial research, we identified that food production can actually co-exist in harmony with improving biodiversity and nature, as well as capturing carbon, and sequestering carbon from the atmosphere.

‘To date we have been struggling to get our message heard by government that we want to be leaders on this, and not just followers, so we decided that our next step was to invite a high profile speaker to talk about climate change, farming and how we need to start measuring food production’s contribution to climate change, and how the Isle of Man can become more sustainable in terms of climate change and food production.’

Professor Allen began his talk by explaining that his particular interest is in how we quantify the role of methane in agricultural emissions. And he went on: ‘The challenge we face is that absolutely, globally, we need farmers’ help to meet our climate goals. There have been many papers been published making the point that if we leave agriculture out of climate policy we’re very unlikely to meet the goals that we have. And there’s every reason to include agriculture in climate policy because agriculture is one of the sectors that is most vulnerable to climate change so it makes sense on both fronts.

‘Part of this is that we need to stop the rise, and ideally start to reduce, methane emissions. Methane is a very important greenhouse gas, it has caused warming and it’s causing a lot of warming at the moment, globally, and so we need to do something about that but we have a rather unnecessary obstacle in the way of addressing methane’s effect on climate which is that it’s very widely misunderstood.’

He said that methane is currently treated as ‘some sort of carbon dioxide equivalent’ but, as he went on to explain, methane and CO2 ‘just don’t behave like each other and therefore the idea that one tonne of methane is equivalent to a certain number of tonnes of CO2 is never really going to work and has led to much confusion over the past 20 years or so.’

The difference between methane and CO2 is that CO2 causes warming at an accelerating rate because it accumulates in the climate system, so the faster you emit it, the faster the warming it causes. Methane emissions, in contrast, have a comparatively short lifetime.

Thus, the impact of methane emissions on global temperatures scales roughly with the rate at which you’re emitting methane, whereas the impact of carbon dioxide emissions scales with the total amount you have emitted over all time.

Not taking this into account has led to the warming effects of methane being significantly overstated.

This is important for agriculture because, as Professor Allen went on to explain, using UK figures as an example: ‘Unlike the UK as a whole, whose emissions are dominated by carbon dioxide, the UK’s agriculture emissions are dominated by methane with a large contribution from nitrous oxide [in fertiliser] and very little coming from carbon dioxide.’

Agricultural emissions peaked in the 1990s but have since been falling, he said: ‘And that actually means that the contribution of agricultural methane emissions to global temperatures has been on a downward slope since 2000. So agriculture as a sector in the UK hasn’t caused very much warming for the past 15-20 years or so. That’s very different from the impression you get from headlines about agricultural emissions. So this difference between emissions and the warming that those emissions cause, is at the heart of what I’m talking about.’

Professor Allen, who has also appeared on the BBC’s Farming Today programme explaining why the current calculation for greenhouse gases means livestock are overly blamed for their effect on climate change, went on:

‘Incentives for farming should be based on warming outcomes.

‘If you’re causing global warming then you probably should be looking at your farming practices and adjusting them to stop doing so.

‘If you’re reducing global temperatures through your farming practice you deserve to be rewarded for that, and, if you’re doing nothing, then you should be treated accordingly.

‘This would be the easier way to include agriculture in climate policy and it would make it much fairer, particularly on livestock farmers.

‘And I believe that would result in faster reductions in the rate of warming than what we’re doing at the moment.’

He added: ‘If we’re asking you to compensate for warming caused by other sectors, like transport who are doing a bad job in reducing emissions, then I think we should be paying you for the service and that’s why we need an open and transparent discussion about how, when and why to reduce emissions, which reflects their impact on global temperatures.

‘And that’s why I’m very keen to talk to farmers to say: “this isn’t very complicated and at the moment you’re being saddled with a system which, if it was designed by farmers, would be very different”.’