Locking down emissions?
Data scientist Bryan Field estimates the impact of New Zealand’s 2020 lockdown on our greenhouse gas emissions and considers what we can learn from this as we work to meet our national emissions targets
At 11:59 pm on Tuesday 17 August 2021 the whole of Aotearoa was placed in an Alert Level 4 lockdown, our second nationwide dose of obsessive sourdough baking, back-to-back Zoom meetings, and online or parent-led schooling.
This second national hibernation prompted me to finish writing this blog, which I started way back in June 2020. I was interested at that time in the effect the 2020 lockdown would have on New Zealand’s greenhouse gas emissions, and whether we could learn anything from this that could help us meet our emissions targets.
Thankfully, the data to enable us to work out an approximate answer to this question is now available.
First, where do New Zealand’s emissions come from?
The Ministry for the Environment released the latest “National greenhouse gas inventory report” in April this year, which contains New Zealand’s emissions data up to the 2019 calendar year and breaks them down by sector. This gives us a good picture of our emissions right up to the start of the coronavirus pandemic.
Our emissions profile is unusual among developed countries. While most others’ are heavily weighted towards energy emissions, almost half (48%) of New Zealand’s come from agriculture — for example, biological emissions from livestock, and applications of fertiliser.
Energy emissions do make up a sizeable chunk of our total emissions though, at 42%. This category includes not just the energy industries, like petroleum refining and electricity generation, but also emissions from cars and other transport — basically any emissions resulting from consuming energy.
The rest of our emissions total is made up by industrial processes and product use (for example, refrigerant from air conditioners, and methanol production) and waste (for example, landfills and sewerage treatment plants), plus a tiny sliver from Tokelau.
Which emissions were affected by the 2020 lockdown?
Agriculture emissions are of course inherently unlikely to be affected by a lockdown — more than three-quarters of these (78%) are from livestock, and our cows, sheep and other farm animals keep on eating, belching etc, lockdown or no lockdown. The other main component of agriculture emissions is soils (20%) — again, no lockdown reductions to be had there.
But significant chunks of energy emissions clearly were affected by the lockdown.
As you can see from the chart below, transport makes up nearly half (47%) of our energy emissions, and during lockdown people weren’t driving or flying anywhere near as much. Those who could work were working from home and many factories and other businesses were closed, so commuter travel was way down.
(Source: Ministry for the Environment, 2021)
The manufacturing and construction sector makes up just over a fifth (22%) of energy emissions. But although most of this sector went quiet during the 2020 lockdown, the essential services that continued, like food processing, still account for a lot of manufacturing/construction emissions. Food processing — for example, milk powder, and meat processing — is the largest source of emissions in that sector (43% of the total). The second-largest is chemicals (like the manufacture of methanol and urea), which makes up about 25% of the total, and this sector was also allowed to operate during lockdown.
Finally, our energy industries account for 16% of all energy emissions. This is mostly from electricity generation (77% of the energy industries total), which was of course an essential service. We know that demand for electricity was lower during the lockdown: although residential power consumption increased with working from home, that was more than offset by factories and businesses being closed. Then a long way back is petroleum refining, at 16% of energy industry emissions, and this is also classed as an essential service.
So, to sum up:
· much of our emissions-producing activity in Aotearoa continues as normal during lockdowns — mainly agriculture, but also those essential services that make up most of manufacturing and construction
· but some significant emissions sources are affected — including transport and our energy industries.
What was the net effect of the lockdown on our emissions?
I next went on to trying to quantify any emissions reductions during the lockdown. The problem is you can’t do this directly yet, as official emissions data covering the lockdown period won’t be released until around April 2022. So instead we have to look at other indicators that may help us understand what happened to emissions over 2020.
Transport emissions: Some big reductions
By far the largest component of transport emissions in New Zealand is from cars, trucks, buses, and other road transport, which together accounted for 91% in 2019. The rest is domestic aviation (6%), domestic shipping (2%), and railways and other transport (1%).
Although we don’t have transport emissions figures for the 2020 lockdown, MBIE releases quarterly figures for CO2 emissions from road transport. We know that for liquid fuels like petrol, diesel, and jet fuel, CO2 emissions make up over 99% of the greenhouse gas emissions, so CO2 figures are a pretty close stand-in here.
Those quarterly CO2 figures for petrol, diesel, and jet fuel for 2019, 2020, and 2021 show that, for each of those three fuel types, emissions were lower during the March and June quarters of 2020 than in 2019 (the last “normal” year). In total, liquid fuel emissions for the June quarter 2020 were down by 28% from the June quarter 2019 — the lowest quarterly figure the September 1997 quarter.
Breaking this down by type of fuel, the reductions for each are pretty dramatic. For the June 2020 quarter:
· petrol emissions were down more than a third (36%) from the previous June quarter
· diesel emissions were down by a fifth (19%), and
· jet fuel emissions were down by nearly three-quarters (72%) — that whopping reduction is consistent with what Air New Zealand has said publicly about their capacity during the June quarter, which implied that it was down by an average of 77% over the June quarter.
This information confirms what we all saw during the 2020 lockdown — there was very little commuting or travel of any sort.
For jet fuel, the September and December quarters of 2020 were also lower than the corresponding quarters in 2019, and this trend has continued into 2021: the March quarter 2021 is lower than the March quarters of 2019 and 2020. This shows that New Zealanders did a lot less flying throughout the whole of 2020.
Electricity generation: Lower demand, but higher emissions
In 2019, electricity generation accounted for 12.2% of New Zealand’s energy emissions (remember that “energy emissions” isn’t just from the energy industries — it includes transport emissions).
During the lockdown, almost everyone was at home and most offices, factories, and other businesses were closed. Basically, electricity demand looked like an enormously long weekend (a month of Sundays, if you like): an increase of 8% in electricity use in homes was more than offset by an 11% drop in commercial consumption of electricity, as businesses paused over the lockdown.
(Source: MBIE, 2021)
But the 2019–2021 quarterly figures for electricity demand and electricity generation emissions show that while demand in the 2020 June quarter was 5% lower than in June 2019, total electricity generation emissions were 7% higher.
This seems counter-intuitive, and a reminder that life is complicated. The explanation is that, quarter to quarter, electricity generation emissions depend on how much fossil-fuelled generation (and to a lesser extent geothermal generation) is in the generation mix. It turns out that with less rain and lower hydro-lakes in 2020 we used more coal to generate electricity than we did in 2019 (but that’s another blog).
We shouldn’t let that higher emissions figure obscure what is, over the medium and long term, the key point: with many offices and factories closed, total electricity demand was lower. And on average, we would expect lower demand to lead to lower emissions — it just didn’t turn out that way in 2020 because of our higher coal use.
The lower demand also persisted for the rest of 2020: total electricity demand for the September and December quarters of 2020 were lower than the corresponding quarters in 2019, with residential demand higher, and non-residential demand lower.
Manufacturing and construction emissions: Up and down
New Zealand’s manufacturing industries and construction accounted for more than a fifth (22%) of our total energy emissions in 2019, with most of this coming from food processing and chemical manufacturing, both of which kept going during the lockdown as essential services. Burning of natural gas and coal in factories is responsible for most of these emissions.
MBIE calculates emissions from the use of natural gas and coal and releases this data quarterly on its website. This shows that:
· natural gas emissions were lower in the 2020 June quarter than the 2019 June quarter, but that coal emissions were higher
· both natural gas and coal emissions were lower in the 2020 September and December quarters than the corresponding 2019 quarters.
(Source: MBIE, 2021)
(Source: MBIE, 2021)
There are probably other factors at play here, and they make it difficult to draw conclusions about the average likely impact of a national lockdown. For example, gas supply in Aotearoa in 2020 has been limited by an outage at the Pohokura gas field. Also, coal emissions are calculated using coal sales, and since coal can be stockpiled this can result in some quarters being unusually high (or low).
The overall net effect
So during the 2020 lockdown we saw:
· a big drop in transport emissions
· a drop in electricity demand, but a conjunctural increase in electricity generation emissions
· a drop in natural gas emissions and an increase in coal emissions (this excludes electricity generation).
Overall, the drop in transport emissions has the biggest influence on our energy emissions since they make up the largest proportion of the total. The other sectors (manufacturing and construction, energy industries, and others) make up smaller shares, so changes to these will have less influence on the total.
Given all this, I would expect the 2020 energy emissions to be significantly lower than 2019 — probably by around 5%. That would correspond to a 2% reduction in total greenhouse gas emissions. (When the Ministry for the Environment releases the National Inventory Report in April 2022 you can tell me how wrong I was!).
If my estimate is accurate, that would make our 2020 energy emissions the lowest they’ve been in 20 years. And as we saw, energy emissions would have been even lower had 2020 not been such a dry year, requiring us to burn more coal to generate electricity.
Lockdown learning
So what can we learn from the lockdown that may help us meet our emissions targets? The following observations might help.
Working from home has a big effect on emissions
This is mainly because when people are working from home they’re driving a lot less, and driving is our biggest source of energy emissions. Meanwhile the additional residential electricity use is offset by lower commercial use and so is likely to result in little or no increase in electricity emissions.
The Climate Change Commission also says that increased working from home is a good idea — their recent advice to the Government on emissions budgets, Ināia Tonu Nei: A low emissions future for Aotearoa, says it’s a key transition for reducing transport emissions.
Many businesses and government agencies in New Zealand are embracing working from home and flexible working policies. For example, some large employers now have rostered days where groups of employees work from home. Others split their teams into shifts and have week-on and week-off working from home.
There are other benefits as well with working from home, including reducing the pressure on office space.
Flying less saves a lot of transport emissions, but makes minimal difference to total emissions
We saw earlier that domestic aviation is responsible for around 6% of New Zealand’s transport emissions, which are 47% of New Zealand’s energy emissions, which are 42% of New Zealand’s total emissions. Even though domestic aviation emissions were way down, this is a big change on a small proportion of emissions so makes little difference to the total. However, all emissions savings help and for many organisations, aviation emissions are a material part of their environmental impact.
Reducing our domestic air travel is something we’re thinking a lot about at MartinJenkins, like many other firms. We’re now a CarboNZero certified company, and in the certification process we found that over 80% of our emissions resulted from domestic flying. As a result, we’re trying hard to cut down on flights.
While we all prefer meeting kanohi ki te kanohi, online collaboration and networking tools like Zoom, Microsoft Teams, and Google Meet allow us to meet and collaborate without having to leave our homes or offices.
At MartinJenkins we also recently started using a tool called Mural (kind of an online whiteboard) that enables us to run online interactive workshops. It’s a different experience, and it’s also pretty great!
Meeting New Zealand’s emissions targets requires many actions across many sectors
Meeting our emissions reduction targets, and our emissions budgets, will require many changes in systems and behaviour for New Zealand’s businesses and people. It will be more difficult than taking a couple fewer flights each year and working from home one day a week (although these things are part of the solution). We need to tackle New Zealand’s emissions from several angles and in a coordinated way — if we don’t, we won’t meet our targets.
This means:
· investing in low-emissions public and personal transport — road transport is our biggest source of energy emissions and so also presents the biggest opportunities (for example, EVs and biofuels)
· investing in low-emissions electricity generation
· decarbonising our manufacturing industries by shifting to lower-emissions fuels and heat sources — for example, biomass and electricity instead of gas and coal
· embracing energy-efficient technologies and conserving energy wherever possible — for example, better insulation in homes, switching to low-emission fuels, and investing in energy-efficient lighting and appliances.
Later this year the Government will respond to the Climate Change Commission’s advice by setting out its plan for meeting the first three emissions budgets, covering 2022–2035. This plan will, hopefully, set us on a path to meet our emissions targets and do our part in helping keep global warming within 1.⁵⁰C.
A first draft of the plan has just been released for public consultation by the Ministry for the Environment. This is likely to elicit a lot of feedback from organisations and people around the country. Let’s hope that the Government, and we, can apply the lessons we learned from being in lockdown to the final emissions reduction plan.
