Thursday, October 08, 2020

Climate Change: Dodgy accounting

Since climate change first became an issue, farmers have been desperately trying to avoid taking responsibility for their emissions - first by outright denial, then by delay, then by various outrageous claims about how we should give them carbon credits for the grass their cows eat. Their latest tactic? Claim they're already carbon neutral:

New Zealand sheep and beef farms are already offsetting the majority of agricultural emissions, new research from Auckland University of Technology shows.

The study led by Bradley Case, a senior lecturer in the university’s applied ecology department, estimates that the woody vegetation on the country’s sheep and beef farms offsets between 63 per cent and 118 per cent of their on-farm agricultural emissions.

The research was funded by Beef and Lamb New Zealand and peer reviewed by chief scientist at Landcare Research, Fiona Carswell and senior ecologist at the University of Canterbury, Adam Forbes.

If the mid-point in the report’s range is used, on average the woody vegetation on sheep and beef farms is absorbing about 90 per cent of these emissions, meaning they are close to being carbon neutral.

If you're in a hurry, "funded by Beef and Lamb New Zealand" really tells you everything you need to know here. And if they really believed this, they'd be demanding the government add them to the ETS so they could start raking in the credits. Again, the fact that they're not tells you something doesn't add up. As for what doesn't add up, the short answer is "everything, because they're not following the agreed rules".

First, under internationally agreed carbon accounting rules, forests which existed before 1990 are incorporated into each country's emissions baseline: they were there, doing whatever they do, so they don't count unless you cut them down. Changes in forest coverage after 1990, whether new forests planted or old ones cut down, represent a change in carbon flows, so do count. Strike one for Beef and Lamb New Zealand is that their report doesn't distinguish between the two - and deliberately so: they chose not to use the LUM dataset which classifies every forest in NZ into these categories for carbon accounting purposes, instead choosing to use a combination of other databases which did not include carbon-accounting types. They were happy to use LUCAS data for how much carbon was being stored however...

Second, those same rules include a definition of "forest": at least one hectare in area, at least 30m wide, at least 30% tree crown coverage from species at least 5m tall at maturity (these rules are also included in the Climate Change Response Act, for obvious reasons). There's some quibbles around temporary changes and regenerating forest, but basicly a forest has to be a decent chunk of actual trees. There are trees in my back yard, but it is not a "forest" for carbon accounting purposes. There may be trees in a farm paddock, but unless they meet the above criteria, it too is not a "forest". Strike two for Beef and Lamb New Zealand is that they don't make this distinction, counting things like scrub and shelter-belts. And they basicly admit this:

Some common farm woody vegetation features are too small to meet criteria for inclusion in LUCAS and are not reported on in the Emissions Trading Scheme (ETS). Burrows and colleagues (2018) provide a comprehensive literature review of available reference carbon stock value and sequestration rate information for non ETS land on farms including; wetlands, riparian strips, pole plantings, shelterbelts, and other retired land that is not eligible for ETS.
So what Beef and Lamb New Zealand's claim basicly boils down to is "we're carbon neutral, if you count all this stuff which doesn't count". In other words, they're not carbon neutral at all, and this is just another attempt to blow smoke - just more predatory delay.

But can't we change the rules so that stuff does count? That's one of the aims of the report: recognising farmers for "non-ETS-eligible woody vegetation elements on their farms". But those rules are set internationally, so good luck with that. And while it seems weird that our carbon modelling doesn't count every tree (like the ones in my backyard), there's some value in a model which underestimates sequestration and overestimates emissions when forests are cut down. "All models are wrong, but some are useful", as the saying goes - and erring on the side of caution seems to be very useful indeed in the face of the current crisis (and the repeated demonstration that all our other models seem to be under-estimating just how fast this thing is moving).

But can't we change it so they just count for the ETS? Not if we ever want to link our scheme with international markets - a core policy goal of the government (and to be blunt, what they're hoping for to hide their massive failure to reduce emissions). If we accept counterfeit "credits" into our ETS, then given their ability to be laundered into other forms of credit, we'd basicly turn our entire system into one of funny money which no-one would be able to trust (so, like Russia and Ukraine, but in reverse). So I don't really see that happening either.

So what should farmers do? Well, if they actually want to be carbon-neutral, they have an easy and obvious way of doing so: plant enough trees in big enough clumps to qualify under the accepted carbon-accounting rules. But that would mean changing what they do. And the whole thrust of everything their peak bodies are doing is an effort to avoid that. So I guess we'll just see more whining and special pleading instead.