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The state of our atmosphere and climate – Expert Reaction

The Ministry for the Environment and Stats NZ have released the latest report on the state of our atmosphere and climate.

Our atmosphere and climate 2023 brings together recent data, as well as insights from research literature, to show how and why our climate is changing. The report also shows the impacts these changes are having on the environment, public health, wellbeing, among other aspects, in Aotearoa.

The SMC has asked experts to comment on the report.

Dr Nick Cradock-Henry, GNS Science, comments:

“The message of ‘Our Atmosphere and Climate 2023’ could not be clearer: Atmospheric warming due to the continued burning of fossil fuels, intensification of some agricultural activities, and changing land use, have a demonstrated effect on global temperature and precipitation patterns.

“For Aotearoa New Zealand, these changes include increased frequency and severity of extreme rainfall events, periodic and more intense drought, and increased climate variability. These effects, in turn, have implications for a range of human activities, over near- and longer-time frames, including changing flood risk and habitability, invasive species and novel pests, and sea-level rise, as well as affecting air quality, and its effects on human health and wellbeing.

“With the release of the report, we have a scientifically robust, defensible record of these changes, and their significance. Building on, and extending previous environmental reporting, it also provides an accessible narrative of the scale, significance, and severity of the challenges we face, and of the urgency of the situation.

“As the report also makes clear, however, this is not exclusively an issue that can be reduced to a set of summary statistics, expressed solely as concentrations of greenhouse gases in parts per million. Reducing these trajectories of climate change to a number alone, overlooks the very nature of the problem, viz., human activity is both an underlying driver of change, and that these activities in turn, will bear the brunt of the adverse effects.

“The atmosphere and climate are an interconnected system, able to be understood and experienced in different ways. By drawing on diverse sources – including the instrumental record, projections of future change, and mātauranga Māori, it provides a rich, and compelling case for all of us in Aotearoa, to consider how these changes will affect diverse aspects of lives and livelihoods, ecosystems, and current and future risks.

“With global emissions continuing to track higher than what is required to avoid the most severe loss and damages, state of the environment reporting, and effective monitoring and evaluation can help raise awareness, and highlight the wide-ranging effects of our current pathways.

“In sum: Aotearoa IS warming; it’s us. We are sure. It’s bad. But we can do something about it.”

Conflict of interest statement: External reviewer, Our Atmosphere and Climate 2023

Craig Stevens, Professor of Physics, University of Auckland, and Principal Scientist, Marine Physics, NIWA, comments:

“The report is a follow up to the 2020 report on the same topic and companion to similar recent reports on the marine environment, land, and freshwater. It takes a consistent view of the ‘pressures’, ‘state’ and ‘impact’.

“As the report notes, the whole approach to environmental reporting is being revised as the separate domains tend to overlap. For example, it is clear that the ocean plays a large role in climate as it is doing most of the heat storage – and by the same token climate reaches out into all other aspects of the environment – and so on. Of course, there is probably no easy way to cut the cake as a more holistic report will either get very large or have to leave things out. Regardless, the direction of approach is secondary to carrying on the record of the changing environment so these reports need to continue in some form.

“The report is built around a te ao Māori framing in a way that supports the narrative from pressures through to impact and provides pathways for our values to connect with the science. It also gives weight to the many, many impacts climate is having on our environment.

“As with previous reports, the other thing I take away is it is a remarkable record of the efforts of the nation’s small group of environmental and climate researchers (and the people supporting them) working hard with demonstrably modest resources. The heaviness of the topic makes for a tough read, but I think it is important for people to do so to get a sense of the wide range of impacts we are, and will, experience with the changing climate.”

Conflict of interest statement: Stevens is a member of the MfE CE Science Advisory Panel

Troy Baisden, Honorary Professor, School of Environment, University of Auckland; Motu Affiliate; Principal Investigator, Te Pūnaha Matatini Centre of Research Excellence, comments:

“The Our Atmosphere and Climate Report, just out in the Environmental Reporting Series from the Ministry for the Environment and StatsNZ tells us much we already know, but it has become a more valuable source of information than its predecessors due to recommendations from the Parliamentary Commissioner for the Environment.

“Rather than reporting on what’s happened in the past, from data that already exists, this report now now has a focus on what will happen in the future and how it will matter to us. It also catalogues not just the data we have, but the data and research we don’t have and desperately need. Both are extremely important with climate change.

“Perhaps most importantly, this report uses a realistic scenario (SSP2-4.5) in the upper middle of possible futures, to provide a sense of what we should prepare for. This contrasts with increasing use of extreme cartoon scenarios based a world that burnt all fossil fuels as fast as possible for the century ahead (RCP8.5). The latter scenarios are becoming too widely used in local government policy when they should only be a trigger for more careful analysis. This report provides a clear alternative recommendation that will make for better policy and planning. The scenario used is broadly consistent with international pledges to address climate change, and represents the levels of climate change we should prepare for even as we try to avert them.

“The scenario choice will help us all respond in stable and sensible ways when addressing the clear statements in this report, such as ‘It is almost certain climate change and repeated severe weather events will exacerbate risks to already vulnerable sectors of the economy.’

“There are many details in the report worth reading. For me, the most useful are those that pull together many pieces of the environment and also warn us that we run the risk of surprises. For example, we are reminded that most of our terrestrial ecosystems are not adapted to fire, and many invasive species make our landscapes fire prone, leading to potential for significant disruptions to ecosystems and landscapes we love. Elsewhere, the report highlights that our greatly diminishing wetlands, especially in lowlands and along coasts, are crucial for carbon sequestration, biodiversity and a range of other ecosystem services.”

Conflict of interest statement: “Troy was a reviewer for the Environment Aotearoa 2022 Report and was recently on an Interim Ministerial Advisory Panel for MfE.”

Professor Adrian McDonald, University of Canterbury, comments:

“The inclusion of outlooks which consider what might lie ahead for our climate are a welcome addition to this report series. The recognition of the connections between the atmosphere, climate, biodiversity and ecosystems are also a welcome addition. While many of the environmental indicators detailed in this report have been updated, there are few surprises and limited positive changes. In particular, this report highlights that more work on the reduction of greenhouse gas emissions resulting from agriculture and road transport are urgently required. The fact that extreme weather events are identified to become more severe and more frequent as our climate changes should also motivate greater action on climate change adaptation and mitigation efforts.

“One of the few bright spots is that the Ministry of Environment has embarked on a significant programme to reform the environmental monitoring and reporting system. This will have important positive impacts in protecting te taiao, as we can not manage what we do not measure. It is also positive to see the acknowledgement that more needs to be done to gain the most value from international research and evidence. However, concrete steps to connect more strongly to international efforts are currently missing.”

Conflict of interest statement: “I participated in the review process for the Our Atmosphere and Climate report as an external independent reviewer, I am also currently a member of the science advisory panel to the chief executive of MfE.”

Dr Luke Harrington, Senior Lecturer in Climate Change, University of Waikato, comments:

“Overall, the report is useful and contains clear, well-considered conclusions. However, I have four issues with the details presented:

    1. “The characterisation of “meteorological”, “agricultural” and “hydrological” drought as droughts which last for different lengths of time (3, 6, and 12 months, respectively), but otherwise calculated using one metric of dryness, is both very odd and wholly inconsistent with the wider scientific literature. It’s not how NIWA characterises drought, it’s not how the IPCC characterises drought, and it’s not how most experts I know would talk about drought.
    2. “The choice to use language to describe uncertainties which is completely different to existing frameworks, like the IPCC, is also odd. Some of the changes are fine but I really don’t understand describing >90% chance as being “almost certain” – that is very strong phrasing, and inconsistent with the wider literature. Specifically, the IPCC refers to >90% only as being “very likely”, while a >99% chance is referred to as being “virtually certain”. Also, the supporting statistics on the Stats NZ website presented to accompany this report use different uncertainty language again, which has the potential to leave the reader confused.
    3. “The presentation of linear trends in extreme events over periods of only a few decades could lead to the wrong conclusions, particularly when it comes to droughts and extreme rainfall (and particularly for regions which are heavily influenced by La Niña or El Niño events). For example, the suggestion from Figure 7 of the report that trends in annual maximum one-day rainfall are “very likely decreasing” over Waikato, Auckland and Taranaki should be interpreted very cautiously.
    4. “The continued lack of useful metrics to characterise extreme heat in these reports remains a point of particular frustration for me. There are a wealth of alternative metrics which are more impact- and decision-relevant in the peer-reviewed literature. In fact, most of the metrics used for extreme rainfall could be applied to extreme heat: trends in hottest day of the year, or changes in the number of days above the local 95th percentile of high temperatures would be a fantastic start.”

No conflicts of interest.

Associate Professor Cate Macinnis-Ng, School of Biological Sciences, University of Auckland, comments:

“This is an important and timely report that highlights the latest information on our changing climate. It includes a comprehensive summary of data showing that climate change is here, and impacts are being seen and felt by communities and species, with damage to infrastructure, ecosystems, oceans and landscapes. The report includes important updates on key climatic factors including drought, temperature and rainfall. While many of the patterns are complicated by topographical factors, patterns are change are becoming more measurable. While we know global climate systems are connected, there are differences in changes in climate in different geographical locations and impacts are also variable between regions according to vulnerability of local ecosystems and species. The report therefore provides essential information relevant to our motu, awa and moana.

“From a biodiversity perspective, there are growing numbers of examples of impacts of climate change being detected. Coastal areas are exposed to erosion, storm surges and ongoing sea-level rise. Seabirds such as hoiho (yellow-eyed penguins) and kororā (blue penguin) are exposed to loss of nesting sites and declines in food availability. In the alpine zone, a mechanism known as thermal squeeze is reducing refugia available for nesting birds as warmer temperatures allow invasive predators to shift into higher elevations. Many of the biodiversity impacts are indirect and can act to exacerbate other conservation threats. For instance, new and existing invasive species (including mammals, insects and weeds) may be favoured by warmer winters allowing range expansions and population increases. Therefore, continuing other conservation efforts (such as pest control) are vital.

“The report highlights that Māori communities are particularly vulnerable to the changing climate due to impacts on mahinga kai, compounding health inequities and other factors. Coastal communities are exposed to frequent flooding and storm damage. Māori should be supported to act as kaitiakitanga to protect lands and water because any society is only as prosperous as its most vulnerable groups.

“Recovery from recent extreme events such as Cyclone Gabrielle will take years and if these events are more frequent, environmental degradation will be compounded. As we head into an El Niño year, we expect extreme fire conditions in Australia that are likely to produce plumes of smoke across our skies and we are likely to see more fires in Aotearoa too. We can no longer dismiss climate change in our mild climate. While mitigation activities have a place in addressing climate change, emission reductions are urgently needed to prevent further warming as quickly as possible. I am alarmed to see so little mention of climate change in the election coverage. I encourage everyone to vote and consider the climate policies when choosing who to vote for.”

Conflict of interest statement: “I was part of the team of senior science advisors for this report.”

Dr Joanne Clapcott, Freshwater ecologist, Cawthron Institute, comments:

“There is no hiding from the fact that the climate we are now experiencing in Aotearoa is having devastating effects on our community and our environment. The Our Atmosphere & Climate 2023 report provides the facts on causes and effects, and for the first time provides outlooks on what’s to come. The facts are provided in four different formats so that the information is accessible to everyone – in a report, statistics on Stats NZ’s webpage, a StoryMap, and education materials.

“The Our Atmosphere & Climate 2023 report demonstrates the ongoing commitment of the Government to ensuring the facts are informed by both Western science and mātauranga Māori. The validity of information is not questionable but rather inclusive, comprehensive and very timely. By showing everyone how we collectively contribute to the state of our climate and atmosphere and what to expect in the future, this report should empower people to make a change for the better.

“From a freshwater ecologist’s perspective, the Our Atmosphere & Climate 2023 report is eye-opening in terms of the outlook for river flows and lake levels. If we are to uphold Te Mana o te Wai then we need to ensure we plan for lower summer flows in some years (e.g. by using less water) and more flooding in other years (e.g. allowing space for water to move by rethinking where we develop land, build homes and infrastructure).

“The report brings with it a sense of urgency – we need to respond.”

Conflict of interest statement: “No conflicts. Joanne is a member of MFE Chief Executive’s Science Advisory Panel.”

Dr Simon Hales, Research Professor, University of Otago, Wellington, comments:

“The sections on current and future health impacts of extreme events and climate change are welcome. However, these sections are very brief and lacking quantitative assessment. There exists evidence from global studies that are not included, but should be, for example there are quantitative estimates for Aotearoa NZ in global modelling studies of heat exposure and mortality, transmission of vector borne diseases and food security. Admittedly, the evidence base from national studies needs to be improved, and future reports can include more details from work that is currently being completed.

“Some impacts of climate change on health are already being seen, and the need for strong intersectoral policies on mitigation and adaptation has never been more urgent.”

No conflicts of interest.

Dr Andrea Byrom, Independent Environmental Consultant, comments:

“This is a significant and comprehensive report, and it is all the more timely given the increasingly obvious impacts of climate change and biodiversity loss on our natural ecosystems and our way of life here in Aotearoa. As the name of the report suggests, atmospheric and climatic indicators (such as greenhouse gas emissions and extreme weather events) are presented, but importantly, holistic linkages and environmental impacts are emphasised through presentation of information on land use change, changes in biodiversity and ecosystem processes, impacts on our oceans and rivers, and implications of a changing climate on our primary industries.

“The report covers the usual ‘pressure, state and impact’ format. Each of these sections is helpfully summarised with an infographic. This simple summary is useful, because each section then dives into a large amount of detail containing numerous linkages and references for those that want to see the original data or publications. In an improvement from previous reports, data up to and including 2022 are used in this report, making it one of the more up-to-date I have seen. This is important if politicians, decision-makers, and government agencies are planning to take action based on the information in the report – we need the most up-to-date and comprehensive information available to make decisions about impacts on communities, planning managed retreat from areas vulnerable to flooding or erosion, and tracking progress towards 2030 and 2050 targets.

“Two sections at the end of this report are particularly useful. For the first time there is a section on ‘outlooks’ – forecasting future trends in climate and atmosphere, and potential impacts of these trends on primary industries, pests and diseases, oceans and rivers, and on people. This section is particularly informative. For example, the information could be used to make decisions about setting emissions targets, planning managed retreat, or scoping environmental bottom lines. Language around the level of confidence in a particular outlook (e.g. “It is almost certain climate change will continue to increase risk to Aotearoa New Zealand’s native and endemic species (high confidence)”) is helpfully explained further in an appendix. Highlighting the degree of uncertainty around the outlooks will be confronting to some, but it is important when describing the behaviour of complex systems.

“The final section of the report – detailing data gaps and areas where more knowledge is needed – is useful for two reasons. First, this section should point to where research effort is needed, and where such effort could be targeted specifically for Aotearoa New Zealand. For example, it takes time and money to collect the most basic monitoring information contained in this report: vital information that is used to develop indicators of state and trend. Yet with increasing fiscal pressures on the organisations that collect such basic data, there is a tendency to stop collecting it. This section of the report highlights its importance. Secondly, it emphasises the need for a more holistic approach to collection of environmental data. This is an area where Mātauranga Māori and the more holistic perspective brought from a Te Ao Māori world view could add richness to the picture of how climate change is impacting Aotearoa for generations to come.”

Conflict of interest statement: “Andrea is the external co-chair of the Chief Executive’s Science Advisory Panel for the Ministry for the Environment, which provides strategic science advice to the Ministry about environmental reporting. She was not involved in scoping or developing detailed content for the Our Atmosphere and Climate report.”

Dr James Renwick, Professor of Physical Geography, Victoria University of Wellington, comments:

“It’s great to see the latest Our Atmosphere and Climate (OAC) report. The series of such reports play a vital role in bridging between the science of the climate system and the human stories we all engage with. The work is based on an excellent sampling of our current scientific understanding, and on solid understanding of the implications of the changing climate. This time, an important addition is that OAC2023 offers outlooks for the future as well as telling the story of the past.

“We know that Aotearoa’s climate is already changing: temperatures, rainfalls, and extremes of both, and we are already seeing clear effects on ecosystems, on agriculture, on our economy, and on our physical and mental health.

“The future outlooks discussed are very well done, based on plausible emissions scenarios, with good use of uncertainty language. The picture they paint is not positive. The globe is very likely to blow through the 1.5°C warming threshold, and may well go through 2°C warming as well. For us, that will mean more droughts, more floods, more coastal flooding, among many other impacts. Marine heatwaves that we have experienced in recent years will be come the average conditions before the end of the century.

“All of this implies huge impacts on ecosystems, weakening the resilience of those ecosystems. No different for human ecosystems – we are part of the climate system and everything we know will change. Negative impacts on New Zealand’s economy and our prosperity will become larger as time goes on, as will impacts on human physical and mental health. There will be big impacts on kaupapa and tikanga Māori and on many aspects of the world around us that we ‘take for granted.’ It’s likely inequalities will increase as those with the least resources struggle to manage.

“Overall, OAC2023 is an extremely well-told but a very depressing story. The knowledge that the globe has just had its warmest September, August, and July, and will most likely record its warmest year in 2023, only underlines the dangers discussed in this report. If we need more justification for taking urgent action on reducing emissions and becoming more resilient, Our Atmosphere and Climate 2023 is the place to look.”

Conflict of interest statement: “I have no CoI’s over this report. However, I was involved in the writing of the previous version, OAC2020.”