Thursday 1 June 2017

The Zero Carbon Act

I've recently been looking at the Zero Carbon Act prepared by Generation Zero, and I'm pretty excited by it.  They've drafted an Act of Parliament that, if adopted, would set in place plans to enable NZ to get to carbon neutrality by 2050.

I'm really pleased that someone is doing this work :-)  We see climate change as one of the biggest near-term threats to the flourishing of our global neighbours, so it's really exciting to see people doing solid work to try and prevent it.

They've basically taken an existing UK act of parliament (from 2008, no less!) and altered it a bit to take into consideration New Zealand's unusual carbon emissions profile.  Whilst for most countries the majority of greenhouse gas emissions are carbon dioxide itself, around half of ours come from the methane and nitrous oxide produced by the agricultural sector.  The different kinds of gases last in the atmosphere for differing lengths of time, so they propose a 'two baskets' approach where the long-lived ones have to be down to zero by 2050 but there is a bit more leeway on the short-lived ones.

The act would require the government to not only set legally binding greenhouse gas emission targets but to set 5-year 'pathways' for how to get there, plus there'd be a Commission to oversee the process.  It also requires the government to identify the challenges a changing climate will bring to New Zealand and figure out ways to adapt to them, and requires them to help our Pacific neighbours to do the same.

If you think that all sounds like a good idea, please 'sign' Generation Zero's petition here.  Your signature will enable Generation Zero to demonstrate that these ideas have popular support.  The petition will be presented to the new parliament after September's general election.

Looking through the how do we get to zero carbon section of the Zero Carbon Act website, I found something else exciting.  They drew my attention to two reports giving possible pathways for New Zealand to get to zero carbon: one from the Royal Society and the other commissioned by a group calling themselves GLOBE-NZ.  That latter group really got my attention: it's a group of 35 MPs (from all parties currently represented in the New Zealand parliament) who believe so strongly in the importance of getting to zero carbon that they commissioned a report to figure out possible scenarios to do it.  I was so excited to hear that: that's more than a quarter of all MPs being prepared to take this stuff seriously.

The two reports are quite different in style, but they both argue forcefully for a strong carbon price if we're going to get anywhere.

The report commissioned by GLOBE-NZ, Net Zero in New Zealand, gives three actual pathways New Zealand could follow (listed below).  The Royal Society report instead looks at the various sectors of the New Zealand economy (energy supply, transport, buildings, industry, agriculture and forests and land use) and identifies ways in which each of those sectors could reduce  their emissions.  For example, they see big savings in the energy supply sector from the moving the electricity grid to 90% renewables by 2025 (and eventually close to 100%); they see big savings in industry by moving heat generation from coal to biomass; and they see substantial savings in agriculture from breeding ruminant animals that produce less methane.  They also consider which changes could be done by individuals, which by businesses and which would required government involvement.  You can download the report and various related materials here or examine at the reduction possibilities they've identified for each sector here.  To put the sector summaries into context, this graphic shows the relative sizes of the emissions from each sector.

The GLOBE-NZ report Net Zero in New Zealand, by contrast, looks at various specific pathways we could follow and examines their consequences:
  1. Off Track New Zealand.  As the name suggests, this isn't a path we want to follow!  In this scenario we use all the relatively easy emissions-reduction strategies open to us (75% more renewable electric power generation, 85% of passenger vehicles electrified, selective breeding of farm animals to reduce methane production etc.) but don't fundamentally change either our economy or land-use practises.  This is expected to result in at 10-25% reduction of greenhouse gas emissions by 2050 - well short of the close-to-100% we're after.
  2. Innovative New Zealand.  This scenario relies on three technologies that do not currently exist (vaccines to make ruminant animals emit far less methane, electrified freight transport and electric heating for high-temperature industrial applications).  Obviously, we can decide to invest in those research areas, but we can't 'decide' to implement these new technologies.  However, should it be possible to do so, implementing these new technologies and coupling them with both the easier changes mentioned in 'Off Track New Zealand' and a 20-35% reduction in pastoral agriculture should see a 70-80% reduction in greenhouse gas emissions by 2050.  Almost there!
  3. Resourceful New Zealand.  If the technologies mentioned above do not materialise, we could see a similar reduction in greenhouse gas emissions by dramatically reducing our pastoral sector and replacing much of it with forestry.  This would obviously be more disruptive - especially to rural people - but may be necessary.  It would not, however, be a long-term fix: the carbon stored in forests is generally released on harvest, so ultimately some innovation will be necessary.
Combining the second and third scenarios would get us more-or-less to Zero Carbon by 2050 :-)

I'm so excited to see people pushing for serious governmental action on climate change and am encouraged that people are starting to do actual scenario planning to see how we could get there.  It's particularly encouraging to see so many MPs supporting this effort.  Sign here if you'd like join your support to theirs :-)


  1. That looks cool! How practical is reducing ruminant methane? What sort of research is going on? Any technology might also find a remunerative application in humans too :-)

    I'm surprised by your comment at the end of 3. Surely increasing forest cover will increase stored carbon, even if that forest is regularly harvested - on average we still have more trees than before. (It doesn't affect net emissions per annum, but it does reduce global net carbon and helps us get down from 400ppm.)

    1. I know that NZ is part of an international research effort into the methane issue, but I don't know how much progress has been made. There is definitely variability animal to animal, and I know efforts are being made to breed for this characteristic. Also, the methane isn't produced by the animal as such but by bacteria in their digestive tract, so people are also looking at breeding/engineering bacteria that take the carbon all the way to carbon dioxide, rather than stopping at methane.

      About forests, the issue is that a *new* forest sucks up lots of carbon, but a stable one sucks up hardly any. In a natural forest, new trees (which remove carbon from the atmosphere as they grow) are more or less balanced by old trees (which release it back as they rot). So the forest mostly only removes carbon from the atmosphere in the years when it is becoming established. Thereafter it's not *quite* at equilibrium (100 years after a tree dies, you'd typically expect about 3% of the carbon it contained to still be in the soil rather than the atmosphere) but it's pretty close.

      Of course, in a managed forest, the trees don't have to decompose. You could cut down the trees and store them in caves underground, for example. But pretty much any other use (even using them in building) will eventually result in them decomposing and re-releasing that carbon. However, even harvesting the trees and storing them for a few decades could buy time, and that would be extremely useful at this stage!

    2. I've just realised - it may not have been clear from my main post - the 'increase in forestry' mentioned in '3' doesn't mean permanent cover - they're thinking of commercial tree plantations, so the trees will be harvested in 20-ish years and then may or may not be replaced. Long-term there is no net reduction in global atmospheric carbon from this strategy - only for the years in which the trees are in the ground.