If this were a film, there is little doubt that carbon dioxide would be playing the baddy – with probably an Oscar nomination on the way.

While a natural part of the atmosphere, released as people and animals breathe and when plants decompose, it is also a pollutant produced when fossil fuels, such as coal and oil, are burned.

The majority of scientists believe manmade emissions of CO2 are responsible for 70pc of the enhancement of Earth's natural greenhouse effect.

But while it is clearly the star of the piece, there are some supporting cast members which it would be dangerous to ignore.

Enter methane and nitrous oxide, the latter probably more familiar as laughing gas.

One man urging us to take these two seriously is Prof David Richardson, dean of the University of East Anglia's faculty of science.

He is leading an international Nitrous Oxide Focus Group which is working on ways to cut emissions in agriculture.

'CO2 is undoubtedly the gas that makes the biggest impact in climate change terms.

'It is the gas that is produced in association with most everyday human activities, so in that sense it is the one the general public know about,' he said.

'It probably accounts for 70pc of manmade greenhouse gas emissions. I don't think many people would argue that CO2 is a big deal.

'However, if we did everything we could to cut CO2 emissions but did nothing about emissions of methane and nitrous oxide it would be for nothing.'

Prof Richardson's focus group includes partners from the John Innes Centre and the Institute of Food Research at Colney, near Norwich but it is also supported by organisations such as Marks and Spencer and Unilever.

'To make fields more productive we apply nitrogenous fertilisers but bacteria can act in the soil and convert it to nitrous oxide,' he said.

'I do not argue against adding fertiliser to fields, I feel it is important to make them productive – the more productive they are, the less forest we chop down to grow enough food to meet the needs of our increasing population.

'Productive fields also absorb CO2 and so can aid carbon reduction but if we can modify the process to minimise the release of nitrous oxide we can make a difference, and that is what we are working on.'

It might seem like research and initiatives into reducing carbon dioxide get all the attention – not to mention the funding – but Prof Richardson says that work into other greenhouse gases is being taken seriously.

And while it is perhaps more important for organisations and farmers to engage in the issue, Prof Richardson believes the public should take an interest in nitrous oxide, which is rising at 0.25pc each year.

'On an every day basis there is more that the average person can do about CO2 emissions because it comes from a lot of different places such as the car they drive, the plane they go on holiday on, the fuel they burn to heat their homes or make a cup of tea. When it comes to methane and nitrous oxide there is less the person on the street can do about it,' he said.

'But people still have to be conscious of their carbon footprint and that includes nitrous oxide.'

If you would like more information on the work being done on nitrous oxide visit www.nitrousoxide.org.