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NZ keeps getting warmer – Expert Reaction

Climate data shows New Zealand is feeling more heatwaves, fewer frosts, rising sea levels, and a decline in taonga marine species. 

Our atmosphere and climate 2020 is a report which pulls together data on our changing climate. It estimates that New Zealand’s greenhouse gas emissions will decrease in the coming decades, but not at a fast enough rate to meet our 2030 Paris Agreement goals.

The SMC asked experts to comment on the report. Feel free to use these comments in your reporting or follow up with the contact details provided.

Dr Jocelyn Turnbull, Radiocarbon Science Leader, GNS Science, comments:

“There is nothing particularly remarkable about the new Our Atmosphere and Climate report. Most of us already know that New Zealand and global greenhouse gas emissions continue to increase, and our climate is continuing to warm. What is wonderful about this report is that it puts the emissions and climate response together in a single readable format, focused on New Zealand. There are lots of nuggets of information that point to where we can focus our efforts on emissions mitigation and adaptation.

“One example is that while road transport accounts for around 20% of New Zealand’s overall emissions, for most households transport makes up around 90% of their personal emissions. That’s good news, because this is a problem that we can solve. With our highly renewable electricity network, switching to electric vehicles immediately reduces NZ’s emissions. Active and public transport and working from home are all ways that each of us can reduce our time spent stuck in traffic and help the climate at the same time.

“While we don’t yet know how to reduce emissions from every sector, ongoing research in New Zealand and overseas is helping us to understand what our emissions really are, and how we can reduce them to meet our Zero Carbon Act and Paris Agreement commitments.”

Conflict of interest statement: Jocelyn provided early input on the types of information MfE include in this report, but was not involved in the data analysis or writing.

Professor Bronwyn Hayward, Director Sustainable Development & Civic Imagination Hei Puāwaitanga, Department of Political Science & IR, University of Canterbury, comments:

“For the first time New Zealand has a really clear report which also has a compelling narrative about how climate change will impact our everyday lives. When today’s 18 year olds turn 58, in 2060, their climate will be virtually unrecognisable.

“The report starts gently, but for the first time it brings to the foreground, how the lives of children growing up today and Maori communities in particular will change in the next 3 to four decades. Climate change has far reaching impacts for our wellbeing, our relationships and working lives and our children’s future. By 2060 the new climate of New Zealand will be accompanied by fires, droughts, floods, sea level rise and coastal inundation. More extreme weather events won’t just cause havoc for our cities and their infrastructure and our processes of food production, it will affect our mental health, as communities struggle to cope with compounding disasters. It will also impact life savings and community hauora/wellbeing as homes, marae and urupa are exposed to coastal erosion and flooding.

“This report is not just about reducing our emissions, it is also a wake up call to complacent governments and voters. The Zero Carbon Act was the first step. Now we have to take action. We need to reduce our emissions and budget, prepare and legislate to protect New Zealand from the coming decades of climate related risks and disasters.”

No conflict of interest declared.

Professor James Renwick, Head of School of Geography, Environment and Earth Sciences, Victoria University of Wellington, comments:

“The report is a comprehensive summary of the state of our climate, including observed and projected trends and changes. It covers many aspects of life and economic activity in New Zealand, and links strongly to wellbeing and how we as humans cope with and adapt to the changing climate. Some of the key messages to come out of the 2020 report include:

“Changes are already observed in Aotearoa, in terms of rising temperatures, melting glaciers, changing rainfall patterns, warming oceans, and rising sea levels. This translates to longer growing seasons, more hot days, less frosts, and many other effects.

“Climate change is driven by increasing greenhouse gas concentrations in the air. In New Zealand, carbon dioxide emissions have grown substantially in the past 30 years, mostly driven by increased transport emissions.

“The changing climate affects our physical and mental health through the effects of extreme weather, changing patterns of disease, and the emotional stresses associated with extreme events. There are also multiple effects on ecosystems and biodiversity, on our economy and on communities nationwide.

“If greenhouse gas emissions continue to increase globally, New Zealand’s climate would see massive changes through the rest of this century, making adaptation very difficult. If emissions are reduced rapidly, in line with the Paris Agreement, climate change across New Zealand would still be significant, but more manageable.”

Conflict of interest statement: James served as a member of the Senior Science and Mātauranga team for the development of the Our atmosphere and climate report 2020. The team provided advice on the report’s content and messaging, while the writing and development work were carried out by staff at the Ministry for the Environment and Stats NZ.

Gregor Macara, climate scientist, NIWA, comments:

“I welcome the publication of this report which shows that we are already observing changes to our climate, and these changes are being driven by greenhouse gas emissions.

“Temperatures to the end of 2019 are assessed in the report, and these show increases throughout New Zealand, especially in winter. The trend continues: this year (2020) we observed our warmest winter on record.

“I have been involved in writing New Zealand’s monthly climate summaries since 2013. In that time, for each location that has observed a near-record low monthly temperature, twelve locations have observed near-record high monthly temperatures.

“January 2018 was exceptionally warm in New Zealand, and it gave us a taste of what a ‘normal’ January may look like in the future. Invercargill had three consecutive days above 30°C, Wellington observed 11 days above 25°C (it usually has just one such day), and Cromwell’s average maximum temperature from 19-31 January was an astounding 33.1°C.

“While we will continue to observe cold temperature extremes in future, a warming climate will make these less likely. In contrast, daily high temperature extremes such as those of January 2018 will occur more frequently.

“I worry about the ominous consequences these warming temperatures have for our glaciers, which are diminishing in size. A recent study of 14 glaciers in the central Southern Alps showed their area had decreased by 21% since 1978. Another recent study showed that the extreme glacier mass loss of 2018 (see here for context) was at least ten times more likely to occur as a result of human-induced climate change.”

Conflict of interest statement: Gregor was NIWA’s focal point for the delivery of climate datasets presented in the report. Gregor also served as a member of the Senior Science and Mātauranga Team which provided advice and critical review of the Our atmosphere and climate 2020 report.

Distinguished Professor Robert McLachlan, School of Fundamental Sciences, Massey University, comments:

This comprehensive report paints a disastrous picture of our failure to reduce emissions over many decades and of significant climate impacts in all areas that are impossible to mistake.

The report notes that our per capita CO2 emissions are 17th out of 32 countries in the OECD. It could be added that for methane we are the highest, and for nitrous oxides the third highest in the OECD. The drivers of increased CO2 emissions are population (+27% in 2000-2018), GDP per capita (+31%), energy intensity (-31%) and carbon intensity of energy (-4%). Thus, the main factor in our emissions record is our failure to decarbonise – not exactly rocket science. (Leining et al 2020 conclude that ‘the New Zealand Emissions Trading Scheme has not significantly reduced domestic emissions to date’).

Where the report says, “We love our cars,” and “New Zealanders’ vehicle preferences are affecting greenhouse gas emissions”, this is not the full story. The transport system (involving private cars, public, and active transport) is mostly determined by the government. Had proposed fuel efficiency standards not been cancelled in 2009, emissions (and fuel costs) would now be noticeably lower. We now find ourselves starting from a very difficult position with regard to transport emissions and will have to play catch up.

The emissions forecasts are alarming. They show a fall in gross emissions of 10% over 2005-2030, and a rise of 16% in net emissions. This predicted failure will now be called to account by the Climate Change Commission. Our obligations in the Paris Agreement require a sustained fall in emissions of several per cent a year.

The climate impacts are extensive. Just to pick a few, Auckland has gone from an average of 25 warm days a year (25ºC or over) in 1972 to 45 days today. Hamilton has gone from 59 warm days a year to 78, Tauranga from 39 to 62. Nelson has gone from 31 frosts a year to 7, Gore from 31 to 11. Anyone would notice these changes. Queenstown has gone from 4 to 14 days a year of very high or extreme fire risk since 1996.

No conflict of interest.

Christopher Cornwall, Rutherford Discovery Fellow, School of Biological Sciences, Victoria University of Wellington, comments:

“The report confirms that New Zealand is still responsible for significant emissions of greenhouse gases into the atmosphere. This will threaten our native terrestrial, freshwater and marine ecosystems. The report only briefly mentions the marine environment, but what it discusses is alarming. Marine heatwaves have caused measurable changes in bull kelp abundances and distribution in the South Island, and replacement of native species with invasive kelp after the event.

“These marine heatwaves will increase in intensity, frequency and duration with ongoing ocean warming. This especially threatens the native kelp forest ecosystems that we rely on for pāua, crayfish and substantial fin fish fisheries.  Additionally, ongoing ocean acidification also threatens the abundance and growth of many marine organisms that are comprised of calcium carbonate skeletons, such as pāua and kina and the calcareous algae that their larvae rely on for settlement.

“We now require higher resolution times series of seawater temperature and pH across the varied marine ecosystems in New Zealand, along with increased monitoring and understanding of species within our waters. If we look to Australia, they have already suffered a series of catastrophic marine heatwaves in numerous locations, as well as ongoing ocean warming, that has caused long-term change in ecosystem function. More frequent and intense marine heatwaves would likely lead to extinctions of those native species with restricted ranges here in New Zealand.”

No conflict of interest declared.

Professor Simon Kingham, School of Earth & Environment, University of Canterbury, comments:

“The continued increase in carbon dioxide from transport is not surprising, especially in commercial vehicles. It emphasises the need to continue to find ways to reduce our greenhouse gas emissions from transport.

“Options to reduce greenhouse gas emissions include:

  1. Travelling less. For example, the COVID-19 pandemic has shown that some people can work at home effectively and reduce travel. People may also chose to live closer to their regular destinations such as workplace, and/or buy more locally produced goods and services.
  2. Use alternative modes of transport such as public transport or walking and cycling. This really only works where there are good alternatives which supports investment in these modes. For freight, rail and coastal shipping can be options.
  3. Switch fuel to non fossil fuels. These include electric vehicles (EVs), biofuels or green hydrogen. EVs numbers are increasing, but not fast enough, while for freight EVS, biofuels and green hydrogen have been examined by the Ministry of Transport.

“Finally, perhaps now is the time to look at whether we can pass on the full and true costs of transport, including greenhouse gas emissions, to consumers.”

No conflict of interest.