NZ needs to slash fossil fuel use

Carbon dioxide comes mostly from burning of fossil fuels. These industrial emissions, once released, stay in the atmosphere for a longer time than other gases such as methane and nitrous oxide.

What role should New Zealand play in climate change?

We pride ourselves on being world leaders - giving women the vote, climbing Mt Everest, taking a stand on nuclear energy.

When Kyoto came around it was sold to the public as a pretty good idea, jump on the bandwagon, sign up and we should be sitting in the catbird seat with plenty of credits in the bank, we might even make some dough as well.

When people think about climate change, they tend only to consider carbon dioxide. Kyoto was actually much broader than that.

That's why in New Zealand over time the mantra has become "all gases, all sectors".

It rolls off the tongue nicely. Unfortunately, it oversimplifies and therein lies the problem.

By lumping all gasses together (that is carbon dioxide, methane and nitrous oxide) there is a tacit assumption that they will all be treated the same.

Carbon dioxide comes mostly from the burning of fossil fuels so we can see a logical way of getting those emissions to zero.

The climate scientists say this is critical as we release a great deal of it and once it is released into the atmosphere it is there for a very long time.

Methane and nitrous oxide come mostly from biological sources and, currently, unless we are going to stop eating, there isn't a way to reduce biological emissions to zero.

However, do we need to reduce biological emissions to zero? Methane breaks down in a much shorter timeframe so while it is considered a more potent greenhouse gas than carbon dioxide, it isn't as important because it isn't accumulating as rapidly.

Likewise, nitrous oxide is also a potent greenhouse gas and it is also much longer-lived than methane, but it is released in much smaller quantities than carbon dioxide or methane.

So while it's important to cut methane and nitrous oxide emissions, it does not make sense to have the same goals and time frames as for carbon dioxide.

Repeating mantras and reducing everything to carbon dioxide equivalents is not helpful to meaningful discussion.

We need to look at the gases separately and look for solutions that are appropriate.

So what can we do? For carbon dioxide, we are consumers and should be reducing fossil fuel emissions.

For methane and nitrous oxide we are producers, however by global standards we are quite efficient producers on a per unit production basis.

If New Zealand doesn't produce a kilo of meat or milk, then it will be produced somewhere else in the world and most likely more emissions will be produced.

So, from a global perspective it makes sense for New Zealand to be producing food rather than shifting production elsewhere.

Now not only are New Zealand farmers efficient food producers, they have also been steadily becoming more efficient, at more than 1per cent a year.

That means over the past two decades New Zealand has reduced its emissions per unit produced by 20-30per cent.

We should keep doing research to keep that trend going and maybe even improve it.

We can also keep exploring new opportunities. We have land, water and a skilled workforce. We are skilled at producing animal proteins.

As farmers we can keep improving our efficiency and taking advantage of new technology.

All of us can reduce fossil fuel consumption by insulating our homes, using solar energy and driving carefully.

Although our individual actions aren't going to save the world, we can do our bit.