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Large lift in methane gas locks in warming

Opinion Piece

Re: An explanation on emission metrics, May 4.

Having an informed public makes for better climate change policy development. On this Steven Cranston and I agree. For this reason I find it difficult to accept that his dogged misrepresentation of farming’s climate warming effects can be anything but cynical. That or slow-witted, your call. Someone who is professionally involved in this field has had more than enough opportunity to understand basic climate dynamics.

Fossil fuel-derived carbon dioxide needs our most urgent attention. The next most problematic greenhouse gas, methane from farm animals, is an important focus for New Zealand’s emissions targets. Whichever metric we use to gauge it, we are still grossly in debt to the planet’s ability to cope.

Where Steven continues to put up misinformation is in his claim that our methane emissions will not be having a warming effect if they are in equilibrium. Methane levels are now 150 percent of pre-industrial levels, a time when the climate was stable, and New Zealand emitted a disproportionate part of this. When a powerful greenhouse gas increases to that elevated concentration, the state of equilibrium of gas production is less relevant than the large underlying increase from that stable era, even allowing for complex atmospheric interactions at higher concentrations (PCE report, page 80).

In other words, net zero methane emissions will lock us into ongoing warming effects, just not any additional warming to that. A bit like a dangerously speeding car no longer accelerating.

We have few levers to pull to slow this planetary nosedive. Biological methane emission control is one of them.

Steven’s advocacy for his clients is to be expected, and him seeking fairness for his special interest group genuine.

But if this results in policy that is at the expense of the rest of us and ultimately our future, then challenging this grip on the status quo is the responsible thing to do.

There are lots of ways to mitigate, and rapidly, and best-practice farmers are at the sharp end of these developments. We should seek to invest considerably more in these ideas rather than find yet more reasons not to.

Donald robson