By Robert McLachlan

It’s now official. Last year was the warmest year on record globally and the first to exceed 1.5°C above pre-industrial levels. This doesn’t mean it’s too late to rein in further warming, but the ambition required rises with each delay in action.

New Zealand is no exception. Current climate policies are no longer a sufficient contribution to the global effort to keep warming at 1.5°C, according to the Climate Change Commission’s first review of the country’s 2050 climate target.

New Zealand’s current 2050 target has two components. Methane emissions from livestock must be cut by 24% to 47% below 2017 levels and emissions of all other greenhouse gases must reach net zero. But the commission has made three main recommendations to raise ambition:

• a net negative target for emissions of long-lived gases (carbon dioxide and nitrous oxide) by removing 20 million tonnes more from the atmosphere than is released each year
• a higher target range for biogenic methane emissions to reach at least 35% to 47% below 2017 levels
• and the inclusion of emissions from international shipping and aviation.

The commission says these changes would bring New Zealand closer to “net zero for all gases”, in line with what is needed to achieve the goals of the Paris Agreement.

The 2050 target review was the last effort for the commission’s outgoing founding chair, Rod Carr, who has become a significant voice for climate action. In his closing words to parliament, he said:

Those who continue to promote the combustion of fossil fuels in the open air without permanent carbon capture and storage are, in my view, committing a crime against humanity.

New Zealand lags behind other countries

The 2050 target is a critical component of New Zealand’s climate response. Under the 2019 Climate Change Response (Zero Carbon) Amendment Act, the commission is charged with reviewing the 2050 target every five years.

The threshold for recommending a change is high. The commission must consider nine key areas and find “significant” developments that justify recommending a different target.

It found three significant changes occurred since the current target was set in 2019.

1. Global action is ahead of New Zealand

While other countries’ current policies, pledges or targets are not sufficient to keep temperature rise at 1.5°C, many countries now have more ambitious targets than New Zealand.

Australia, Japan, US, Canada, EU and Ireland all adopted full net-zero targets in 2021. Finland and Germany have or are considering net negative targets. Among countries with high biogenic methane emissions, several now have full net-zero targets.

2. Scientific understanding of climate change has changed

Climate impacts are appearing sooner and with more severity than the scientific community understood when the target was set in 2019.

3. The burden shifts to future generations

The increased risks and impacts of climate change have implications for inter-generational equity. Delaying action shifts costs and risks to future generations.

The commission’s report also explores New Zealand’s reliance on large-scale commercial exotic afforestation to meet its climate targets. This is one reason why Climate Action Tracker rates New Zealand’s response as highly insufficient and commensurate with a 4°C world.

Carbon in trees is part of the biosphere and will never be stored as permanently as fossil carbon. To take a case in point, Cyclone Gabrielle in 2023 (made worse by climate change) damaged forests, farms and infrastructure, and removed the social licence for forestry in the region.

How the recommended target was set

The commission’s work is tightly prescribed by law. It looked at four possible ways of sharing the global 1.5°C task: equal per capita emissions, national capacity, responsibility for historic warming and the right of all peoples to sustainable development.

New Zealand’s current target does not meet any of these standards, but the commission says the new target would at least meet the “national capacity” criterion and would be feasible and acceptable. However, it would still see New Zealand contributing two to three times its share of global warming this century.

The commission’s assessment is independent of any global warming metrics such as GWP100 (currently the UN standard). Instead, the commission computed New Zealand’s historical and future contribution to temperature rise directly. Both commonly used historical baselines, 1850 and 1990, yield similar results.

New Zealand’s government is currently particularly at odds with the commission’s recommendation on biogenic methane. It appointed a separate advisory panel last year which put forward a target consistent with causing “no additional warming” to the planet from agricultural methane emissions.

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But the commission rejects this idea, finding that unless the rest of New Zealand’s target were to be strengthened significantly, this would not be consistent with the Paris Agreement or the country’s own climate law.

International aviation and shipping emissions

In a quirk of climate diplomacy, international aviation and shipping emissions were excluded from the original 2050 target. But as the commission points out, they most definitely contribute to global warming and are covered by the temperature target of the Paris Agreement.

Other countries are moving in these areas and the International Civil Aviation and maritime organisations have net zero 2050 goals in place. Air New Zealand and the global shipping giant Maersk both support including these emissions in the 2050 target, which the commission finds to be achievable under multiple different pathways.

New Zealand’s dependence on shipping and air transport is a challenge. The commission puts the combined emissions from these sectors at 6.7 megatonnes – 20% of total CO₂ emissions and close to all industrial or all passenger car emissions. The aviation industry in particular is planning for growth, which, unless addressed, will blow the 1.5°C carbon budget both for New Zealand and globally.

Drawing on “net zero pathways” prepared by the international aviation and shipping industries, the commission finds that including these sources in New Zealand’s revised 2050 target would be achievable. The sectors would not necessarily have to enter the Emissions Trading Scheme, but the status quo (under which these sectors do not attract GST, fuel tax or a carbon charge) is inequitable with other sources of economic activity.

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This article is republished from The Conversation under a Creative Commons license. Read the original article. The author acknowledges the assistance and contribution of Paul Callister.

By Robert McLachlan

Under the Paris Agreement, countries periodically submit NDCs or ‘Nationally Determined Contributions’. The first one covers emissions from 2021 to 2030, and the second (covering emissions out to 2035) is due early next year.

The Ministry for the Environment is consulting on our second NDC (due 8 December 2024). The world is currently on track for up to 3 ºC of warming by 2100 and the UN has called for more ambitious near-term targets. As I wrote earlier, New Zealand is currently warming at 3 degrees per century; unless emissions reduce, we’ll blow through both 1.5 and 2 ºC in fairly short order.

Here is my submission.

Public submissions close on Tuesday 1 October on the Crown Minerals Amendment Bill which, amongst other things, will reverse the 2018 ban that limited new petroleum exploration permits outside onshore Taranaki.

There’s a lot going on here, but one thing I would like to bring to the Government’s attention is this graph, showing how the New Zealand solar power industry has grown 46% annually for ten years in a row. It’s poised to continue, with an enormous pipeline of new projects under consideration.

But it could be stopped in its tracks by an anti-climate government. It’s happened before, with geothermal power and with wind power, both of which were stopped for a decade until the passage of the Zero Carbon Act which showed that the climate crisis was being taken seriously. It happened again with the cratering of electric car sales: anti-climate signals from the top do seem to have an effect.

For these solar projects and others like them to go ahead, developers need to know that demand for low-carbon electricity will be there. That demand comes from phasing out fossil fuel, particularly (in the context of this Bill) natural gas.

Here is my submission:

By Robert McLachlan

The Energy Quarterly from the Ministry of Business, Innovation and Employment reports fossil fuel emissions from electricity generation, oil, and (industrial, i.e. non-electricity) coal and gas. The June 2024 issue shows that oil, coal, and gas are all down from the previous quarter.

Electricity emissions increased, but even this is something of a good news story: despite inflows to the hydro lakes being at 90-year lows, new wind and geothermal plants completed in the last few years are avoiding 2 million tonnes of CO2 per year. As a result, we entered winter with lakes at average levels and they never fell anywhere near the warning line.

The lowest level of storage, around 1500 GWh, was not unusually low – similar or lower levels were reached in 4 of the previous 14 years.

Thus the investments triggered by the pro-climate Zero Carbon Act of 2019 meant that an electricity shortage was avoided. And annual electricity emissions, though off their lows, are still 59% below peak.

Oil accounts for two-thirds of emissions from the burning of fossil fuels. However, even oil consumption has been fairly flat for 11 quarters in a row, and remains 4% below record highs. High prices and behaviour change (and to a lesser extent EVs) are responsible. The cost of oil in real terms per capita has tripled since the 1990s.

Industrial coal use is at record lows, and now 41% below peak. Gas use is 23% below peak. Overall, annual emissions are 9% below their peak.

By Robert McLachlan

NIWA’s ‘7-station series’ shows warming of 1.11 ºC per century:

But is that straight line a sound model of the trend?

Recently, Berkeley Earth released preliminary data for all countries in the world. Although based on data from 86 sites, rather than 7, it gives very similar results to NIWA:

Smoothing the data shows the underlying trend:

Some years stand out well above the trend. 1938 was particularly warm, at 1.15 ºC above pre-industrial, a record that would not be matched again until 1971. In April 1938,

So much sediment washed into the river that the Esk Valley was left covered in silt one to three metres deep when the floodwaters subsided. The water was more than two metres over the floor of the Eskdale Railway Station, and silt lay 1.6 metres deep. The silt was dug out of some houses but the old road running up the valley remains buried beneath the road since built over it. Once the silt had consolidated on farmland, new fences were installed; some posts were placed on top of the old buried posts.

– Inundated: Snow in Hawke’s Bay in August 2016 echoes the catastrophic flood of 1938, National Geographic, November 2016

1992 was particularly cold, at –0.36 ºC, a return to pre-WWII temperatures caused by the eruption of Mt Pinatubo in the Philippines. The effect on New Zealand (1 ºC below the trend for those years) was twice the world average. Kane Hartill recalled:

1992… Amazing year, a rigorously cold winter. I was studying geology at Canterbury, and spending plenty of time doing ski-mountaineering trips to Cook and the Canterbury ranges. It seemed most of the year was drab grey with bone chilling damp cold southerly quarter winds… On one visit to Mt Hutt in late August the snow wall on the side of the access road was just over double bus height, about 8 meters. The upper T-bar lift line was cut down deep into the snow pack, there were 4-5 meter walls of snow each side along much of the ascent. I snowboarded with ice axe in hand from the summit of Mt Rolleston down the Otira valley to beyond the footbridge >5km. Then in the summer we used to go snowboarding on the permanent ice field in the upper Otira valley… it became hollowed out with caves through the later 90’s and disappeared. Pity, the most accessible ice caves in NZ at the time, 30-45min walking track from the highway… they were stunning blue like the Iceland ones.

The smoothed temperature record provides an estimate of the rate of warming:

The warming appears to accelerate fairly steadily until about 1990, rising from zero to about 1 ºC/century. Then the rate of acceleration triples, with the warming rate increasing to over 3 ºC/century today. Because of the small land area and resulting variability, this estimate is pretty rough. But it is consistent with the global rate, which is also around 3 ºC/century. An acceleration to that kind of rate is expected under a medium-emissions scenario. On the other hand, warming stops when emissions stop.

Overall, New Zealand saw 0.89 ºC of warming in the 20th century, and another 0.73 ºC since 2000. The total, +1.6 ºC, is closer to the world average for land (+1.9 ºC) than for ocean (+0.9 ºC).

Submissions close on 25 August for comments on the Government’s second emissions reduction plan, which covers the period 2026-2030. You can also comment on changes to the first (2022-2025) plan, although that’s a bit of a joke because the proposed changes have already happened.

The Government now favours a “least-cost” approach, which I take to mean “least cost for a given level of risk and ambition”. But that very much depends on how you measure cost and risk. To me the plan looks high cost, high risk, and low ambition.

It’s proposed to delay decarbonisation of transport and energy by 15-20+ years – but tree planting would be at similar levels as advised by the Climate Change Commission. How does that add up?

Here is my personal submission.

Ian Mason, University of Canterbury and Robert McLachlan, Te Kunenga ki Pūrehuroa – Massey University

The recent failure of a deal to deliver hydrogen-powered trucks to New Zealand, and the removal of a NZ$100 million government rebate scheme for green hydrogen users in the 2024 budget, make a transition to the much-lauded energy technology increasingly less certain.

The government had invested $6.5 million for the purchase of up to 25 heavy freight hydrogen trucks as part of a wider energy strategy due by the end of the year. But the US company Hyzon, which makes hydrogen fuel-cell trucks and had been modifying diesel trucks to use hydrogen, pulled out at short notice.

Nonetheless, interest in hydrogen for future transport and energy systems has soared globally, and New Zealand is no exception. But we argue that critical voices have been largely missing from the debate here.

In New Zealand, green hydrogen (which is produced with electricity from renewable sources) has attracted government support of $186.3 million from 2017 to 2023. This provided funding for a hydrogen refuelling network, vehicle conversions and purchases, research, and the establishment of the New Zealand Hydrogen Council (now Hydrogen New Zealand).

Proponents of green hydrogen argue it is essential for fuelling economic sectors they believe will be hard to decarbonise by direct electrification. As well as heavy road transport, this includes shipping and fertiliser production.

But opinions differ considerably on which sectors to focus on, and whether hydrogen is the best choice.

Evolution of the narrative

In the wake of the previous government’s ban on new offshore oil and gas exploration, the 2019 H2 Taranaki roadmap outlined a vision for the region as a leader in hydrogen production.

Former energy minister Megan Woods reinforced this, indicating her government would be interested in any associated economic opportunities. This largely positive narrative continued in two further government reports.

The first, A Vision for Hydrogen in New Zealand, suggested the case for hydrogen was already settled:

Hydrogen is poised to fulfil its potential as a clean alternative to hydrocarbons in the global pursuit of decarbonisation to address climate change.

Development of green hydrogen was largely implicit in the second report, the Interim Hydrogen Roadmap, which aimed to:

optimise the potential for green hydrogen to contribute to New Zealand’s emissions reductions, economic development, and energy sector to the extent compatible with our broader electrification goals.

We analysed these reports using a content analysis approach focused on identifying how often strengths, weaknesses, opportunities or threats are mentioned. This revealed the words “opportunities” and “challenges” were used frequently, while “weaknesses” and “threats” were absent.

The use of “strengths” was confined to perceived advantages of New Zealand as a location for hydrogen production. Where difficulties were identified, they were framed as challenges rather than weaknesses.

This optimistic tone is generally reflected in descriptions of several government-funded projects, including green hydrogen research at GNS Science, and international collaborations such as the German-NZ Green Hydrogen alliance.

Media reports have typically reflected the enthusiastic narrative. Of 83 articles on green hydrogen published in New Zealand between 2019 and 2023, only 15 (18%) contained any critical analysis.

Critical voices need to be heard

While some experts have voiced serious concerns about green hydrogen, this has not featured prominently in the debate in New Zealand.

For example, research by University of Cambridge engineering expert David Cebon shows battery electric vehicles are superior to hydrogen vehicles for heavy transport.

The emergence of fast (five minutes or less) automated and manual battery-swap systems, which provide an alternative to high-powered fast-charging systems, supports this point.

Climate and energy strategist Michael Barnard, who covers the green hydrogen debate extensively, writes:

Since 2000, application after application of hydrogen has found it to be inefficient, ineffective and expensive compared to obvious alternatives.

A German rail company which launched the world’s first hydrogen line last year has since opted for cheaper all-electric trains. Rising costs have also forced one Austrian state to abandon plans to introduce hydrogen buses.

Recent research suggests developments in battery-run and fast-charging electric trucks could soon make hydrogen fuel cells superfluous in road transport in most cases.

UK energy analyst Michael Liebreich has quantified the immense scale, significant impracticalities, enormous subsidies and costs associated with green hydrogen.

Liebreich’s “hydrogen ladder” ranks both actual and potential uses. It provides an evidence-informed guide on where to best focus attention and resources. Based on this, the previous government’s funding for the manufacture of green fertiliser (for which hydrogen is an input) was a sensible allocation.

In New Zealand, a 2019 report sponsored by industry and the government, and a letter from the Parliamentary Commissioner for the Environment, have both provided some critical analysis of the potential for green hydrogen.

Towards a new narrative

The previous government’s commitment to finalise New Zealand’s hydrogen strategy, and to deliver an overall energy strategy, remains in place. But we need a more nuanced perspective.

This must start with an acknowledgement that hydrogen is an energy carrier (which has to be produced from other sources of energy), and not an energy resource like solar radiation, wind or hydro.

We need an approach that can continue to adapt to changes in “hard to abate” sectors of the energy system. Critiques of green hydrogen need to enter the discussion if we are to make informed choices.

Government policy on this topic must be informed by independent advice free from commercial interests. A new green hydrogen narrative will enable us to focus our limited resources on applications with the best chance of delivering on New Zealand’s decarbonisation and sustainability aspirations.

This could include key New Zealand industries switching from fossil fuels to hydrogen to produce green steel, green ammonia and fertiliser and green methanol.

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The authors are grateful to Paul Callister for his helpful comments and suggestions.

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Ian Mason, Adjunct Senior Fellow in Renewable Energy Systems Engineering, University of Canterbury and Robert McLachlan, Professor in Applied Mathematics, Te Kunenga ki Pūrehuroa – Massey University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Robert McLachlan

Fifty years ago, in the early 1970s, the environmental movement was in its first heyday. Pesticides, herbicides, and air and water pollution were on the front page every day. One of the key debates from that time was the question of what was the true underlying cause of the environmental crisis – what today we would call the global ecological crisis.

In one camp, Paul and Anne Ehrlich pointed to overpopulation and overconsumption. Their influence reached as far as Elmwood Normal School, Christchurch, where as a little boy I did a project called “People Pollution”. In the other camp, Barry Commoner completely rejected their arguments and blamed modern technology almost entirely. His argument was based around the extreme suddenness with which pollution had grown.

Fast forward fifty years and this question, is the root cause overconsumption or is it bad technology?, is still with us today. In reality it’s a bit of both (and they affect each other), but that’s not a very satisfactory answer.

I’m going to look at this in the context of New Zealand, and, in a twist, instead of looking at what our choices are in the near future, I’m going to look backwards over the past thirty years. What were our realistic options, and what did we choose? The past has one big advantage over the future: we know what technologies were actually available at the time and how they evolved. What if we had chosen different technologies starting in 1990?

Would it have been possible to have an economy broadly like ours, but with much less impact on the environment?

To make things simple I’ll just look at CO2 from fossil fuels. (It would be an interesting exercise to repeat this thought experiment for other environmental impacts.)

There is little suspense here because we know we have not been a great performer:

I’ve started this graph in 1973, the date of the first oil crisis. Higher prices put a lid on consumption for a while and spurred attention on efficiency. France turned towards nuclear power, Sweden towards biomass, first for district heating and then for liquid fuel. The UK started getting out of coal and into natural gas. In New Zealand, the Maui gas field had been discovered in 1969, at that time the eighth-largest gas field in the world, prompting extensive negotiations as to what to do with it. After a detour into self-sufficiency in liquid fuels (the world-first synthetic petrol plant at Motonui), ultimately the gas was used for new energy-intensive industries such as drying milk, and for electricity; much of it was exported in the form of methanol.

Since 1990 the New Zealand population and its economy have grown more rapidly than those of the EU or the US. The population of NZ has grown 60%, as has real GDP per capita. Both of those things tend to increase emissions, other things being equal. The economy is two-and-a-half times the size it was in 1990.

Meanwhile, fossil fuel burning has grown by 5.5 Mt or 25%. So, some relative decoupling, but still not great.

Let’s look at the main sectors.

Electricity

Electricity emissions rose from 4 MtCO2 to 10 Mt in 2005 (all that gas!) and then fell to 2-4 Mt. They could have been nearly zero by now. We could have built geothermal 20 years (even 50 years) earlier than we did. Wairakei (1958) was the first large-scale geothermal plant in the world; we were world leaders. (My first science job was a geothermal modelling project with the DSIR, in 1983.)

Then we could have built wind 10 years earlier, and kept at it instead of stopping and starting; and when Australia showed the way with solar we could have followed them, again 10 years earlier. Notice how both geothermal and wind show decade-long lulls in which entire nationwide industries stall due to insufficient focus on the environment. Just now, all three technologies are expanding again, but maintaining this long-term requires a determination to decarbonize the whole economy.

Industry

Industrial emissions have gone from 7 to 8 Mt, mainly due to the dairy industry. They had other choices, which they are only just getting around to installing now. (We did ‘save’ 1 Mt by closing the Marsden Point oil refinery, shifting the emissions to Singapore.) Likewise, instead of sending our scrap iron to Japan for 30 years, we could have recycled it here using electricity, as (thanks to the previous Government) we are finally getting around to. I’ll say we could be at 5 Mt now without much change to the economy.

Buildings

Emissions from buildings are up from 3 to 4 Mt – they could easily gone down if we had gone harder for energy efficiency and built up instead of out. What and where to build, and what to do with the existing stock of buildings, are still up for debate. These are contentious issues, so I’ll say the best we could have done is 3 Mt – but at least we would be well on the way to zeroing out this sector.

Transport

Oh yes, transport. This is the real culprit. Up from 8 Mt to 13.5 Mt, essentially the entire increase in our emissions. New Zealand had a car-dominated transport system in 1990. It still does today, only even more so. Could we have done better?

To be fair, transport is a difficult sector, one that all countries struggle with. But our choices have been worse than most. We could have imposed fuel efficiency standards in 1978, like the US, or in 2009, like the EU. (We did try in 2009, but the scheme was cancelled due to a change in Government – the cabinet paper makes for sad reading today.) Instead this was not introduced until 2023, and is about to be revised. We don’t even have a gas-guzzler tax like the US and Australia.

In New Zealand, transport emissions per person rose from 2.6 to 3.2 tonnes. In the UK, they fell from 2.0 to 1.8 tonnes. Since we had more scope for improvement in both efficiency and mode share, I’m going to say we could now be at 2.2 tonnes. We would still have a largely car-based transport system, just not quite so much. That would put our present total transport emissions at 9 Mt.

Adding it all up, CO2 emissions could have gone from 22 to 17 Mt using only technologies that were already in existence and proven in other countries. Even better, we would then be well on the way to ending the use of fossil fuels altogether.