What does this actually mean?
Tasmania’s carbon emissions profile
To understand this it is helpful to divide greenhouse gas emissions into two types:
Gross emissions
Those predominantly related to the burning of coal oil and gas in:
• Energy production
• Transport
• Industrial processes
• Agriculture
Land related emissions
Those related to land use and forestry activities.
(Technically called “Land Use, Land Use Change and Forestry” or LULUCF.)
The combined effect of both types is called net emissions.
Let’s look at how these have changed since 1990.
GROSS EMISSIONS
(Mainly transport, industry & agriculture)
If we look at gross emissions, we can see that Tasmania’s emissions during the past thirty years. The chart below shows average emissions taken over five-year periods 1990-1994 and (thirty years later) from 2014-2018. In fact, our gross emissions have actually increased by about 6 per cent over that time.
Although our gross emissions have been dwarfed in the past by LULUCF, they are still large on a per-capita basis.
If Tasmania were one of the 37 OECD countries, our per-capita gross emissions would only be exceeded by six countries. Australia (heading the pack), US, Canada, Luxembourg, New Zealand and Estonia. We are certainly world leaders in this regard.
LULUCF
(Land related emissions)
Now let’s look at forestry. Over many decades, Tasmania had significant forestry activity which mainly converted native forest timber into pulp which was, in turn, converted into paper. Note that paper has a lifetime of only a year or so before it breaks down, returning carbon dioxide to the atmosphere.
Over those three decades, Tasmania’s emissions have been dominated by LULUCF, about 11 million tonnes of carbon dioxide per year being released into the atmosphere.
Added to this were gross emissions of about 8 million tonnes per year, resulting in net emissions of about 19 million tonnes a year, which were among the highest per-capita emissions in the world.
So, what has changed, to make us appear so good?
Around 2010, logging in native forests was more than halved due to changes in global prices and an increased demand for plantation timber (driven partly by environmental advocacy).
Recovering and regrowing of our forests began to draw carbon dioxide out of the atmosphere such that LULUCF ’emissions’ became negative at around minus 9 million tonnes per year.
As noted above, gross emissions have changed little and are still about 8 million tonnes a year, resulting in present net emissions of about minus 1 million tonnes a year.
That is, on paper we are removing carbon dioxide from the atmosphere — which is why the Premier can claim “We have hit our target of net zero emissions’’.
But we ask… is this fair and honest?
The validity of including LULUCF emissions in any assessment of our climate aspirations, targets and performance is controversial, for several reasons:
Estimating LULUCF is very uncertain:
The science is poorly understood and required observations are sparse. Historical estimates are therefore often re-calculated as fresh data comes in, and as understanding improves. For example, as a result of re-calculation, this year’s assessment of Tasmania’s LULUCF for 2017 differs from last year’s assessment by 1.8 million tonnes — more than the annual emissions from our entire transport sector.
Our very definition of LULUCF is somewhat arbitrary:
How do we apportion these emissions between natural and human causes?
Carbon Dioxide can shift from forests to the atmosphere relatively easily and quickly:
Although a tree may take decades to grow, it can be destroyed in hours, as was evident from our recent disastrous bushfires. This is in contrast to coal, oil and gas which, until the arrival of humans, had been safely locked up for many millions of years.
The present draw-down of carbon dioxide is not permanent:
It will reduce over decades as the regrowing forests mature.
In summary
The draw-down of carbon dioxide is a direct result of the recovery of forests from decades of logging and paper production, during which Tasmania had among the highest per-capita emissions in the world.
Is it fair we use this recovery from past bad behaviour to offset our gross emissions now?
If our Premier really believes we are “a world leader in mitigating climate change’’ what advice could he give to other countries?
Perhaps it is this:
- Do nothing to reduce your gross emissions over a quarter of a century.
- Heavily log your forests for a few decades (resulting in world-leading per-capita emissions), then substantially reduce logging and take credit for the drawdown of carbon dioxide from the atmosphere that will inevitably follow.
It’s a perverse logic, isn’t it?
[A version of this article was published in The Hobart Mercury on July 31 2020.
The author, Dr John Hunter, is a member of Climate Tasmania.]
