Mean heat: Marine heatwaves to get longer and hotter by 2100

Maps of MHW

New research from the Deep South Challenge: Changing with our Climate and NIWA shows that NZ could experience very long and “very severe” marine heatwaves by the end of the century.

Marine heatwaves are already becoming a common experience for New Zealanders. In newly released research, scientists say that by 2100, the 40-odd marine heatwave days we currently see in a normal year will increase to between 80 days (low emissions, best-case scenario) and 170 days (high emissions, worst-case scenario) by the end of the century. For some regions, such as southern tip of the South Island, there is a high chance that marine heatwaves start to last more than a year.  

The research also explores the intensity of future marine heatwaves, or just how warm they will be. For coastal waters, average marine heatwave intensities will increase by 20% (best case) to 100% (double, worst case) by the end of the century. For the North Island, this means an average marine heatwave could be between 0.5°C to 2°C more intense than they are today.

Research lead Dr Erik Behrens (NIWA) says that the chance of marine heatwaves becoming a permanent fixture is worrying.

“The impacts of climate change are happening all around us and New Zealand isn’t immune. We’re just coming off the back of one of our most intense marine heatwaves, like what we experienced in 2017. Our work indicates that this will start to become the norm as time goes on. Marine heatwaves can have significant impacts both at sea and land. They kill off corals, disturb ecosystems, and can also pose a problem for fishing and aquaculture, as well as contributing to land heatwaves and climate extremes across the country.

“What is particularly interesting is the disparity between regions, with some coastal areas predicted to experience a much bigger intensity, frequency and duration of warming seas than others. This is important to know so we can focus our efforts in helping marine ecosystems adapt to these changing conditions,” says Dr Behrens.

The analysis draws on the New Zealand Earth System Model and its “high-resolution ocean grid”. The grid helps us understand smaller-scale ocean processes (as opposed to vast oceanic currents, for example), making more accurate regional assessments like this one possible.

Kate Turner, Climate Change Knowledge Broker (Deep South Challenge) says, “we’re excited that research like this is now possible, giving locally relevant, and even coastal, insights into climate impacts in our oceans. These projections also tell us we need to start adapting to our changing climate now. Organisations, iwi and hapū, councils and communities up and down the country are experiencing these impacts already. We need to really focus on how we can support their adaptation planning today.”

Maps of MHW
Marine heatwave conditions: left – today, right – 2100 (NIWA, Deep South Challenge)

Tony Craig, a partner with marine consultancy Terra Moana, comments, “Both industry and recreational fishers are already noticing changes in the kinds of species that are caught and where.  It’s hard to see current fisheries being resilient enough to withstand increases between 80 and 100% of median marine heave wave intensities by the end of the century.”

Marine heatwaves occur when water temperatures stay in the warmest 10% of historical observations for at least five days.

This work will be presented during a free webinar on Thursday 17 March 2022, 12-1pm. Find out more here.

The full paper can be found here.

A Mean Heat

A snapper amongst kelp. Image credit: Shaun Lee, iNaturalistNZ, CC BY. Colour changed from original.

How the climate is driving marine heatwaves

A Mean Heat - how the climate is driving marine heatwaves, a constant change seminar by the Deep South Challenge

In collaboration with the Sustainable Seas Challenge, we bring you this online seminar with Erik Behrens (NIWA), Tony Craig (Terra Moana) and João De Souza (Moana Project)

Anyone who’s been in the water this summer will have felt that things are heating up. Swimmers are talking about how the ocean is uncommonly warm and fishers are catching sub-tropical species further south than ever before. We’re on the tail-end of a marine heatwave, and new research tells us these are going to get longer and stronger.

Marine heatwaves are already becoming a common experience for New Zealanders. In newly released research, scientists say that by 2100, the 40-odd marine heatwave days we currently see in a normal year will increase to between 80 days (low emissions, best-case scenario) and 170 days (high emissions, worst-case scenario) by the end of the century. For some regions, such as the southern tip of the South Island, there is a high chance that marine heatwaves start to last more than a year.  

The research also explores the intensity of future marine heatwaves, or just how warm they will be. For coastal waters, average marine heatwave intensities will increase by 20% (best case) to 100% (double, worst case) by the end of the century. For the North Island, this means an average marine heatwave could be between 0.5°C to 2°C more intense than they are today.

Research lead Erik Behrens (NIWA) says that the chance of marine heatwaves becoming a permanent fixture is worrying.

“Marine heatwaves kill off corals, disturb ecosystems, and can also pose a problem for fishing and aquaculture, as well as contributing to land heatwaves and climate extremes across the country.”

In this seminar, Erik will take you through his research into “Marine heatwaves and the link with climate extremes,” alongside insights on what it means for our fisheries and marine ecosystems from Tony Craig (Terra Moana) and João De Souza (Moana Project).

A recording of this seminar will be available on our YouTube channel in the days following this seminar. Please subscribe to our newsletter to stay up-to-date.

New research preparing rangatahi for an uncertain climate future

Māori and Pasifika rangatahi will be among the most impacted by climate change. This project, funded through Living with Uncertainty is set to grow their capability to lead communities in an uncertain, climate change impacted future. 

It comes as the IPCC releases the Working Group II report: Impacts, Adaptation and Vulnerability, highlighting how climate change will impact communities both physically and socio-economically, and ways in which people can adapt to these impacts.

Reshaping communities: how and where we live, how we use our land, and how we work, is at the heart of The Deep South Challenge’s latest funding round, Living With Uncertainty. 

Before covid-19 hit our shores, bringing forth the now well-known adage of “living with uncertainty”, researchers were invited to put forward proposals for projects that would help prepare communities, iwi-Māori, policy-makers and decision-makers to live with the uncertainty of climate change. 

Mana Rangatahi: Climate change decision-making is one of three new climate adaptation projects which will work with Māori and Pasifika rangatahi aged 10 – 14 from two different Canterbury schools at high-risk of flooding. 

It is led by Canterbury University professors, Bronwyn Hayward (a coordinating lead author of Chapter 6 of the IPCC report), Executive Director Māori, Pacific and Equity Sacha McMeeking (Ngāi Tahu) and Distinguished Professor and Director of Macmillan Brown Centre for Pacific Studies, Steven Ratuva. 

The project will work with rangatahi to design pathways to navigate the climate future, by drawing on their cultural narratives and values to conceptualise how they will respond to climate scenarios. 

“Māori and Pasifika youth will be most impacted by climate extremes, but also have the potential to contribute much needed transformative leadership to how we collectively survive and thrive in a climate change impacted future,” McMeeking says.

A number of climate hui/talanoa/tala will be hosted with rangatahi and their whānau to consider future climate scenarios and how they might redesign their communities in the face of these. 

Professor Ratuva, Director of the Macmillan Brown Centre for Pacific Studies says it is important climate adaptation focuses on whānau and communities, rather than individuals, Ratuva says. 

“The consequences of one’s action impacts on others so addressing the climate crisis is a collective responsibility.” 

Professor Bronwyn Hayward says she is excited to be supporting a project which is inspired by the power of ‘intergenerational learning’. 

Other projects funded through the Living With Uncertainty round include: Simplifying real options analysis for climate change adaptation, which will create a tool for councils to more simply appraise the likes of roading improvements and sea walls; and Supporting community wellbeing when water is scarce, looking at the effectiveness of measures to protect water security. 

The strength of indigenous values in guiding communities and businesses in the face of climate change is a major finding of a recently published paper on culture and climate change, authored by Priya Kurian, Debashi Munshi, Sandy Morrison, Raven Cretney and Lyn Kathlene. This paper features in the IPCC Working Group II report. 

Conducted prior to the pandemic, it uses tourism as a case study of how cultural politics is influencing climate adaptation. 

It found over half of tourism businesses were extremely concerned about climate change. While there was some awareness of its major impacts such as shrinking glaciers and rising sea levels, there was ultimately a lack of urgency in the sector for dealing with large-scale disruption in the near future.

Where adaptation approaches had been adopted, they tended to be carbon-intensive solutions like using helicopters to reach glaciers and generating artificial snow on ski-fields. 

Māori tourism businesses were found to have a greater awareness of climate change impacts, because of their intimate relationship with the natural environment. 

“I think tourism is about storytelling and introducing those stories relevant to Te Āo Māori, and Papa and Rangi is one way in which you can educate people about the environment and kaitiakitanga,” a Waitomo Caves guide interviewed for the research said. 

The values of kaitiakitanga (guardianship of nature) and whānaungatanga (relationships and connections between people, communities and all living things) were found to provide a possible pathway for not only tourism businesses but at a political level to guide more sustainable practices into the future. 

A concerted political push was needed, with a national climate adaptation plan with clear guidelines for tourism businesses, was needed to future-proof the sector against climate impacts, the report concludes. 

Emissions targets still lacking, but world leaders taking heed of climate science

It’s never been clearer that “drastic and rapid” emissions cuts are needed to curb catastrophic climate change. While targets put forward at COP26 might have fallen a little short, at least world leaders and policy-makers appear to be taking heed of climate science.

Much was made of the perceived successes and failures of the 26th Conference of the Parties (COP26). Hailed as successes were the international commitment to protect forests and an agreement to “phase down” coal use. But these were also failures, because this commitment lacked details on implementation and legal “teeth”, and the phase-down might open the door to some countries burning coal for many years to come. Underpinning negotiations were the simulations of our future climate, set out in the 6th Assessment Report of the Intergovernmental Panel on Climate Change, released just months prior. In the face of the most weighty and consequential decisions policy makers face today, science must, and arguably did, play a pivotal role.

The first volume of the IPCC report – dealing with physical climate change – appeared in August. Its Summary for Policymakers said it is “unequivocal that human influence has warmed” the climate system, and that strong and rapid reductions of CO2 emissions, reaching net zero, are required for the climate to eventually stabilise. Failure to achieve this would result in continuing warming and increasing frequency and intensity of most types of weather extremes. Incidentally, several countries participating in COP26 had recently experienced such catastrophic weather extremes, all made much more likely (or even at all possible) by climate change.  

As a climate scientist, I am pleased to see that my discipline is playing such an important and growing role, when really our common future is at stake… this is a reason for hope and a counterexample to the many falsehoods that often poison our discourse in this and other contexts. 

Olaf Morgenstern

However, the influence of science was not restricted to this momentous time. Many media outlets have reported that Nationally Determined Commitments (NDCs) would result in 2.4 degrees of warming by the end of the century (optimistically assuming that the NDCs will actually be met…). But these claims are not directly based on the 6th Assessment Report. The report discusses the future in terms of predefined Shared Socioeconomic Pathways (SSPs). At their core, these are stories of plausible future human behaviour, including conflicts, competition, technological progress and uptake, regional rivalry, and international collaboration to combat climate change. After translating these stories into future CO2 abundances and other physical “climate drivers”, the SSPs are like islands of knowledge, gained by running climate models driven with these scenarios, in the sea of possible climate futures. By interpolating smartly between these islands, we can however fill in the voids between them; this is how the projection of 2.4 degrees of warming under the present NDCs was arrived at.

The role of science in the COP26 process is exemplified in that now over 90% of the world is covered by zero-carbon targets, up from 30% just two years ago. The parties to the Glasgow Climate Pact express “alarm and utmost concern that human activities have caused around 1.1°C of global warming to date and that impacts are already being felt in every region”. This is an unusually strong language for 197 countries to agree on. While COP26 clearly left more progress to be desired, to me it is a sign that increasingly the voice of science is being heard. As a climate scientist, I am pleased to see that my discipline is playing such an important and growing role, when really our common future is at stake. Given the dire prospects implied in high-emissions scenarios, such as the disappearance of whole nations whose territories would be swallowed by the sea, to me this is a reason for hope and a counterexample to the many falsehoods that often poison our discourse in this and other contexts. 

The IPCC working group II report, Impacts, Adaptation and Vulnerability, will be released in February. This will be followed by the IPCC Working Group III report on mitigation in March. Keep an eye out on our blog for more information, and contributions from our scientists.

Introducing our new Challenge Director Phil Wiles

“Get in there… and help some really smart people do what they need to do”

We’re really excited to welcome Phil Wiles to the Deep South Challenge, who takes on the role of Director in the new year. Phil brings a breadth of experience across climate policy, community engagement and science, and we know he’ll steer the Challenge ship well through our critical final years.

Taking on the Directorship at the Challenge, while continuing to keep a foot in at the Climate Change Commission (CCC), is the next stage of a career that began in physical climate science but has expanded to encompass policy, people and culture. Phil is a natural choice to lead the Challenge through an important time in Aotearoa history: we have a National Adaptation Plan in development, managed retreat legislation on the cards, and mandated climate-related disclosures, which together mean that all sectors must get better at understanding climate risks (and opportunities). 

Most importantly, everyday New Zealanders are beginning to drive for adaptation in their own communities. There is much opportunity for evidence to inform policy, and Phil is focussed on ensuring we meet this challenge.

“I think the [national] science challenges have been a massive success… for me it’s about making sure that the really good work that has been done can be translated into something that is useful.”

Phil (who is also the husband of our earlier Challenge Manager Lucy Jacob!) began his career as an oceanographic technician at NIWA. He took this strong foundation in research to American Samoa (with Lucy), where he spent three years with the local Environmental Protection Agency. 

From there, the couple travelled to nearby Apia, Samoa, where he worked for SPREP (Secretariat of the Pacific Regional Environment Programme), an intergovernmental organisation that supports Pacific nations with science advice and support on environmental issues. Phil’s focus was on the impact of climate change on oceans.

It’s a huge amount of work, but if you can get in there and guide some of it, and help some really smart people do what they need to do, that’s what I’m really excited about.

Phil Wiles on joining the Deep South Challenge

This was less about “time on boats taking measurements”, and more about connecting information with people who needed it. 

“There’s some really talented people doing some really amazing stuff,” he says, and the role was an “opportunity to give them a bit of support, so they could do more”. 

Phil returned to Aotearoa with his family in 2014 (their eldest son was born in American Samoa, “the skinniest little ginger American Samoan,” Phil laughs). This is where Phil moved from community engagement to policy, taking up a position with the Ministry for the Environment. It was “a bit of a shock”, but he came to enjoy the different work, in particular relishing his role guiding New Zealand’s contribution to the Paris Agreement. 

In his current role at the Climate Change Commission, he’s continued his work in the mitigation space, where he leads the agriculture, forests and waste team. 

What excites him the most about joining the Challenge is being part of driving forward climate adaptation and connecting that research with iwi Māori, rural communities, and industry. 

“It’s a huge amount of work, but if you can get in there and guide some of it, and help some really smart people do what they need to do, that’s what I’m really excited about,” he says. 

Phil’s official start date as director is January 31,2022.

Meeting electricity demand in 2050: Climate change & energy supply

Spotlight on Deep South Challenge energy researcher, Jen Purdie

Jen Purdie, lead researcher in our Climate change impacts on NZ electricity project, is helping to future proof our energy supply, as we move away from fossil fuels and towards 100% renewables.

Having worked across industry and research, Jen is now bringing her experience to bear on the problem of climate change. How will future rain and snow supply impact hydroelectricity? Can we hydro our way out of our energy issues, or do we need to think more holistically about this critically important challenge?

Jen has spent most of her career in the electricity sector, working for 14 years at Meridian Energy as a water, wind and energy modeller, and then a climate change modeller. She’s currently a Senior Research Fellow at the University of Otago. Jen describes her industry and research experiences as complimentary. In industry, she explains, you have to respond to issues immediately as they arise, while research gives you “the luxury of sitting back and looking at things with an umbrella view… taking time to go into things in more detail”. 

Jen is now modelling the impact of climate change on our electricity sector up to 2050. The electricity model she’s using is on loan from Meridian Energy, while Richard Turner from NIWA is providing wind projections. Jen’s team also includes previous Deep South Challenge researchers, including NIWA hydrologist Christian Zammit, and University of Otago community development and energy guru Janet Stephenson

In rare good news, unlike the impact of climate change on other sectors, hydro-electricity may be in better shape by 2050. Our largest hydro dams are based in the west of the lower South Island, an area expected to get wetter under climate change. More winter rainfall is likely in the Southern Alps, which along with warmer temperatures will mean 10 percent more water flowing into hydro lakes in winter (when we need it) instead of being stored as snow. 

Pumped-storage hydroelectricity works like this: When there’s a period with excess water – say, when there’s a lot of snow melt in the summer but little demand for power – that water is pumped back uphill to an upper reservoir (using the excess power). In winter, when electricity demand increases and there may be a shortage of water, the dammed water is released downhill to the generator. 

Jen Purdie at a southern hydro-scheme, December 2021

These hydro schemes are key to our electricity system. They’re the “big battery banks,” as Jen puts it, which supply 55 per cent of the nation’s power. However, building more hydro dams as a means for meeting future demand is not necessarily the best or only option. Hydro schemes face difficulties obtaining resource consents, in part because “there is little appetite for flooding valleys”. 

And this option for meeting future electricity demand is also costly. The government has turned its attention to the feasibility of building a pump hydro-scheme at Lake Onslow in Central Otago. If funded (a decision is expected in 2023), the scheme could cost $4 billion. 

It’s one solution, and “a good one…,” Jen says, “but there might be other solutions that don’t have such an environmental impact and don’t cost as much”.  

Another “dry winter” solution the team is exploring in the project is demand response, where consumers opt to reduce or cut off their power during peak hours, using smart appliances. So, for example, while you might plug in your electric car as soon as you get home from work, it may not begin charging until 2am. 

This can be taken further, Jen says. For instance, the grid assesses how much power is already in the vehicle when it’s plugged in, figures out how much may be needed overnight, and, if the vehicle has excess energy stored, can take back some of the power back into the network. 

Consumers would get paid for the service they’re providing to the grid… There’s talk already in industry that we need to get systems set up so this can happen smoothly, efficiently and fairly invisibly to people.

Jen Purdie

Project modelling by Jen, student Aleida Powell and colleague Michael Jack has found demand-response could take 20 percent off electricity demand during the winter peak by 2050. One obvious benefit is a reduced need for expensive infrastructure. 

And in 2022, one of Jen’s students will potentially looking at the practicalities of demand response: whether smart meters and appliances are up to the task; whether government regulations require updating; and whether the Electricity Authority would need to build demand-response solutions into its code. 

Modelling our future electricity sector is full of “massive uncertainty”, Purdie says, which is a major challenge for her and her team. As an example, uncertainty around how many electric cars we’ll have in 2050 (anywhere between 200,000 to 4 million), means Purdie must model a wide range of scenarios. 

Her approach is to take the extremes of these kinds of scenarios, and find a middle ground. This gives industry some confidence and the tools to consider their investment options, from hydro to hydrogen plants, from solar to wind, and including devices that control demand response. 

There’s no single solution, Jen says. For Aotearoa to reach its carbon zero goals by 2050, it will take all of these, big industry participation and a change in the way consumers expect to use electricity.

Jen’s project is set to conclude in late 2023, so there’s a lot of water left to run through the river. If you want to get in touch with us about Jen’s research, please email our Partnerships Director Waverley Jones.

Tikanga Māori can and must lead adaptation strategies

Funded through our Vision Mātauranga programme, Te Tai Uka a Pia carves a path for iwi and hapū to create climate adaptation strategies grounded in Tikanga and kōrero tuku iho (iwi and hapū narratives/histories passed down through generations).

Iwi in Te Waipounamu are using ancestral narratives to guide how they respond to the breakdown of coastal urupā, and disruption of traditional food gathering practices, among the many physical and cultural impacts of climate change in their regions.

Deep South Challenge research by Sandy Morrison (Ngāti Whakaue, Ngāti Maniapoto, Ngāti Rārua, Te Ātiawa) and Aimee Kaio (Ngāpuhi, Ngāi Tahu, Te Arawa), released today as a Story Map, explores the climate challenges facing iwi of Ngāti Rārua, Te Ātiawa, Ngāi Tahu whānau o Awarua and whānau o Wharekauri.

Sandy Morrison (L) and Aimee Kaio at Te Rau Aroha Marae in Motupōhue (Bluff)

The research project, Te Tai Uka a Pia, finds that tikanga Māori, such as karakia, kōrero tuku iho, waiata, haka, wānanga (at-place), cleansing rituals and mahinga kai, are crucial methods of understanding climatic changes within iwi and hapū rohe, and how to respond to them. 

Holding wānanga at sites that are important historically, culturally and spiritually is critical to igniting whānau understandings of climate change which inform how they adapt to it. 

The kōrero tuku iho of Hui te Rangiora, a Polynesian navigator who travelled deep into the Southern Ocean before resting at Riuwaka, was in danger of being lost, Morrison says, but it’s gained new life as a tool for increasing tamariki and rangatahi awareness and understanding of climate change. 

“For the first time, our whānau are telling our stories. We’re keeping these precious tāonga alive which hold knowledge of our wāhi tapu, our connection to place, and how to interact with it,” Morrison says. 

Wānanga with whānau explored the impacts of sea level rise on wāhi tapu such as the low-lying urupā at Mōtu Hui te Rangiora. Climate change will likely erode the kōiwi (remains) of their ancestors, and whānau are considering the appropriate tikanga to respond to this. 

Ka mōhio rātou te hiranga o tēnei mea te ‘climate change’, i roto i te kaitiakitanga i te tirohanga i te kaitiaki o te tana taiao, ki tana ao whānui.

They [tamariki] know about this thing called ‘climate change’ because it is encompassed implicitly within their worldview and their role as kaitaki within the environment.

Pohe Stephens, Kapa Haka tutor for Motueka Mai Tawhiti kapa

Further South in Te Waipounamu, climate change is already interrupting the tītī (muttonbird) harvest for Ngāi Tahu whānau, a mahinga kai practice of Ngāi Tahu whānui for generations.

The oceanic manu have been closely observed by mana whenua for centuries, and mutton birder diaries going back to 1970 have shown tītī are in decline, most likely because of food availability and wind patterns when hunting in the Southern Ocean. 

“This time is precious for our mutton-birders each year,” researcher Aimee Kaio says. “They know their islands so well, and the way they document change over time and understand exactly what they’re seeing with their manu is observational research at its best.”

Protecting the tītī harvest is a key climate adaptation priority for Ngāi Tahu whānau o Awarua, as the mahinga kai practice reaffirms their whakapapa to the islands. 

Tamarereti as depicted in the mahi toi of Te Rau Aroha Marae in Motupōhue (Bluff) PHOTO: Meriana Johnsen

The whānau and rangatahi of Te Rau Aroha marae in Motupōhue (Bluff) look to the kōrero tuku iho of early Polynesian navigator Tamarereti to understand how tūpuna might have responded to crisis, challenge or change, in order to move forward in uncertain times. 

Whānau member Manuariki Tini composed the Ngāi Tahu waiata Taku Taurapa, featured in the Story Map, to capture the landmarks which guide whānau back from Rakiura to Motupōhue (Bluff). 

She says the research “encapsulate[s] everything important to us as Māori, to us as hau kāinga, to our Bluff whānau/community”. 

“This is an inspiring and motivational tool regarding the vital changes to make, the roles our people and hapū can and must take, in the best interests of our future generations,” she says. 

You can access the Story Map here

Long-term planning for drought needed now – report

With COP26 underway, it’s timely to consider how, regardless of future emissions reductions, New Zealand is facing a future with more severe and longer-lasting bouts of drought.

With that in mind, we have released our report, Growing Kai Under Increasing Dry, produced in conjunction with Our Land and Water and Resilience to Nature’s Challenges National Science Challenge.

The report holds insights from a series of online webinars and a one-day symposium which brought together farmers, growers, industry bodies, researchers and government to discuss how the primary sector can adapt to drought and other severe weather events caused by climate change. 

Some interesting insights from the report are: 

  • The directors of the three National Science Challenges co-signed a clear message to the primary sector that planning to adapt to intensifying drought conditions must start now, led by regional councils, industry bodies and central government.
  • If this planning doesn’t start now, farmers and growers may become trapped into land uses that no longer suit the environment, increasing pressure on already vulnerable rural communities.
  • Farmers and growers are already making incremental changes to how they use their land to adapt to climate change but must be better supported.
  • The economic cost of drought is large, with sheep and beef farm profits expected to halve by the end of the century.
  • Our primary export market needs to be protected but we are in a strong position to evolve and adapt.

Change is hard – messy in the middle, beautiful in the end.

Fraser Avery, Marlborough farmer

A national long-term climate change adaptation strategy that supports farmer resilience is needed to reduce the economic risks of increasing drought, says Nick Cradock-Henry, a Manaaki Whenua Landcare Research senior researcher who presented at the events.

Research has found that between 2007 and 2017, drought cost New Zealanders around $720m – six times the figure for flood damage. Severe losses of up to 54 per cent in sheep/beef farm profits are expected by 2100.

The report calls for regional councils to undertake clear planning for likely future climate scenarios in their regions, and to engage with farmers and growers to develop a shared understanding of the scenarios’ implications for the primary sector.

Regional and local councils will also need to focus on the resilience of rural communities and the mental wellbeing of farmers, the report says.

Andrew Tait, NIWA’s Chief Scientist for Climate, Atmosphere and Hazards, presented on how by the mid-to late 2000s the entire country, except for coastal South Island, is predicted to have exacerbated drought conditions which are expected to be more extreme in the North Island and east of the South Island.

Growing Kai Under Increasing Dry symposium

Farmers in most North Island regions can also expect to spend 10 per cent more time in drought by the middle of this century.

For fourth generation Marlborough sheep and beef farmer Fraser Avery, who spoke at the symposium, “drought isn’t a new challenge”.

He farms out at Lake Grassmere, north of Blenheim, an area prone to long, hot summers with little to no rainfall.

Despite the strain this places on his family, he has shifted his farming practices to suit the changing climate by reducing the capital stock (often breeding stock, intended to be farmed for 12 months) from 80 percent to 50 percent.

Fraser says this approach gives him the flexibility to run more stock in a good season, and less in a drought.

“If you can create as many options as possible, then you feel like you’ve got a card to play but when you’re struggling for options, you feel a lot more pressure and stress.”

The clear message from the symposium was that while farmers need to begin incremental adaptations to climate change, they must be better supported to do so. People in regional councils, industry bodies, government and science must take responsibility for developing ‘system adaptations’ like improving drought modelling, and larger, transformational adaptations such as identifying new land use opportunities.

Calling for a new Director

We sadly farewell our Director, Mike Williams, who has just been appointed to the role of Chief Scientist, Oceans, at NIWA.

We’re now on the lookout for someone with proven experience in multi-disciplinary research, science management and governance to lead our Challenge for the next three years.

Mike started with the Challenge in 2014 as a Programme Leader, before taking on the role of Director in August 2016. He has seen us through a period of significant development, especially as the national conversation around climate adaptation has taken root.

When he first took on the role, Mike says the debate was dominated by mitigation and that “not enough people were thinking about how to cope with climate change that is already locked in.” His strong support for our multidisciplinary Challenge Leadership Team has helped turn the dial towards preparing for inevitable climate impacts.

We wish Mike all the best for his new role at NIWA, he will be missed.

Mike’s departure creates an exciting opportunity for an experienced science manager, administrator and communicator to help us fulfil our mission of ensuring that New Zealanders can adapt, manage risk and thrive in a changing climate. Bring your knowledge of science, your passion for people-centred climate adaptation, and your understanding of iwi and hapū aspirations to the table. Here, you can play a pivotal role championing the adaptation aspirations of our communities.

We’re looking for someone with good relationships in te ao Māori and with a strong background in climate policy and/or science.

In your role, you’ll help incorporate new practices that connect iwi/hapū, industry, regulators, planners and policy-makers to ensure our nation is ready for the climate changes ahead of us.

Tono mai / apply here at: https://www.seek.co.nz/job/53915539?type=standout#searchRequestToken=36e03e91-c595-4b85-a97f-fa5b81ccc8be

Getting hot, hot, hot – climate modelling explained

Scientists are now predicting higher temperatures with more certainty, so what’s changed? One of New Zealand’s leading climate modellers, Dr Olaf Morgenstern, helps demystify the science behind the latest climate projections

By now, you might be familiar with the major insights from the IPCC’s Sixth Assessment Report, Climate Change 2021: The Physical Science Basis, collating developments in climate science over the last 8 years. 

It paints a clearer, albeit more terrifying, picture of how the earth’s atmosphere, oceans and land have changed since pre-industrial times. 

The world’s leading climate scientists, representing every region on the planet, have then simulated five different scenarios up to the end of this century. 

The 2015 Paris agreement set the target for avoiding catastrophic climate change and ecological disaster at below 2 degrees, striving for 1.5 degrees. Six years later and the prospects have significantly diminished. 

“We are likely going to cross that 1.5 degree threshold even in the most optimistic of these scenarios,” the Deep South Challenge’s Earth System Modelling and Prediction programme lead, Dr Olaf Morgenstern says.

The IPCC report is clear that “rapid, deep and sustained cuts to emissions” are needed to keep the global temperature anywhere near these targets. It’s only in “the most optimistic scenario” Morgenstern says, where there is cooling after 2050 by removing more CO2 from the atmosphere than we add, that global warming could reach less than 1.5 degrees by the end of this century. 

Whether we’ll have the technological capability to remove CO2 from the atmosphere, or whether polluters are prepared to change their ways, will be the focus of Mitigation of Climate Change, set to be published in 2022. It’s clear the current targets put forward by different nations won’t be enough to meet the 2 degree target. The upcoming “Conference of the Parties”, scheduled for November in Glasgow, will reveal whether countries are prepared to rise to the challenge.

This report focuses on the physical science of climate change – a complex task using some of the largest supercomputers in the world to generate simulations of our future climate. The amount of data produced for the report is much larger than what was generated for the previous IPCC report (5th Assessment), Morgenstern says, who was one of 13 lead authors of Chapter 3, Human Influence on the Climate System.

Simulating our future climate requires some of the largest supercomputers in the world, as NIWA scientist Dr Jonny Williams explains

Questions have been raised about whether the latest climate models are “running hot”. A standard experiment in climate modelling involves doubling the amount of CO2 in the atmosphere and waiting until the Earth system has settled into a new balance, or “equilibrium”. Calculating the average warming since the pre-industrial age is then the “equilibrium climate sensitivity” of the model. This single number is a simple way to characterise climate models.

It takes hundreds to thousands of years for all temperature-influencing processes to come to balance, E.G for atmospheric warming to permeate into the depths of the ocean, so the climate sensitivity is calculated only once the system has settled into a new balance or “equilibrium”.

It is true that several of the most recent climate models are “running hotter” than others before them. But the IPCC assessment doesn’t rely solely on these models for its assessment of climate sensitivity. Rather, other insights are used, such as understanding the average global surface temperature during past periods of the Earth’s history. 

By combining these insights, the assessed climate sensitivity uncertainty has in fact halved. The best estimate of climate sensitivity, calculated in the report, is 3 degrees; this is unchanged from previous IPCC reports. However, scientists have reduced the error estimates around this number. For the first time, this improved understanding of climate sensitivity is used to assess end-of-century warming. 

Scientists use an amalgamation of climate models to measure the changes in the atmosphere, land and ocean. For large-scale climate features – temperature, precipitation, radiation – the report finds climate models today perform better than those of previous generations. But while there have been “incremental improvements” in climate modelling, there are still areas where more research is needed. 

Climate models don’t accurately capture what is happening here in Aotearoa. Our maritime climate is largely influenced by what’s happening in the surrounding ocean. The clean air over the Southern Ocean is creating an “error” in simulations as scientists seek to understand how aerosols interact with the clouds.  

Then there’s the small observed increase in Antarctic sea ice extent over several decades which in recent years has given way to an abrupt decrease. This complex behaviour isn’t generally captured in climate models. Understanding these unique features of our Pacific climate is at the heart of New Zealand Earth System Model (NZESM), a model being developed by Dr Olaf Morgenstern and his team. This is being developed in collaboration with the UK MetOffice. Without their support, the Deep South Challenge wouldn’t be able to undertake such a mammoth task.