The artificial intelligence boom is driving a global expansion in data centres – and with it, public debate over their heavy demand for power, water and land.
Increasingly, governments are weighing their economic benefits against concerns about pressure on electricity grids, local communities and the environment.
That debate has now reached Aotearoa New Zealand. Singapore-based Datagrid has secured approval for a NZ$3.5 billion, 280 megawatt (MW) AI data centre near Invercargill.
While Datagrid’s “AI factory” is expected to more than double the country’s data processing capacity, it has drawn some public unease. The Green Party recently proposed a one-year pause on new AI data centres while stronger rules are developed.
Similar regulatory debates are playing out overseas in places such as New York, Amsterdam and Australia.
That’s particularly relevant to New Zealand, where electricity shortages can already emerge during dry years when hydro lake levels are low.
But do data centres inevitably have to become another energy-hungry burden on electricity systems? And, if designed and operated differently, could they help support a cleaner, more flexible grid?
Can data centres be grid assets?
The answer lies in how these centres consume electricity. If they can adjust when and how they use power, they could become increasingly valuable as New Zealand adds more wind and solar generation to its electricity system.
But how, precisely?
Many of the computational tasks performed in data centres are not time-critical. AI model training, large-scale data processing and other batch computingcan often be scheduled for periods when there is plenty of renewable electricity, wholesale prices are low or the grid is under less strain.
Rather than increasing demand during evening peaks, data centres could help absorb surplus wind and solar generation that might otherwise be curtailed. This gives renewable developers greater confidence that the electricity they generate will have a buyer, making new projects more financially viable.
In Australia, flexible data centre demand is helping support new solar and battery investment. Britain’s electricity system operator has suggested new data centres could be built faster in Scotland where renewable electricity is most abundant and the grid can best support them.
Data centres can also provide services besides simply consuming electricity. Most already contain sophisticated electrical infrastructure, including uninterruptible power supply (UPS) systems, batteries, backup power systems and, increasingly, on-site renewable generation.
With appropriate market rules, these assets could help stabilise the grid by providing fast frequency response and reserve capacity. Data centres themselves could temporarily reduce demand during periods of network congestion.
Many existing battery and UPS systems are already technically capable of providing these services, although market arrangements would need to evolve before they could participate more widely.
As well, data centres’ large and predictable electricity demand could underpin more renewable generation.
Long-term power purchase agreements could improve the financial viability of wind and solar projects – particularly smaller community-owned developments that can otherwise struggle to secure finance.
Datagrid’s power purchase agreement with Mercury covers 140MW of its 280MW electricity demand. This leaves open the possibility that the remaining demand could underpin a new generation of community-owned renewable energy projects across Southland.
Getting the incentives right
There is no doubt data centres are large electricity consumers. But that does not mean they have to be a liability for the electricity system.
Poorly planned projects could increase peak demand, require costly transmission and distribution upgrades, worsen local network congestion and compete with other users for renewable electricity.
But with the right design and market incentives, data centres could instead become part of the solution. By shifting when they consume electricity, they can help absorb variable wind and solar generation, reduce pressure on the grid and make it easier to operate a highly renewable electricity system.
For regulators, the key question isn’t whether data centres are good or bad for the electricity system – but how to create the planning rules, market incentives and operating arrangements that allow them to become part of the solution.
If New Zealand can get those settings right, data centres can help integrate renewable energy, support community energy projects and improve grid resilience.
Water levels across several of Europe’s major waterways have dropped to exceptionally low levels, setting new records in some areas.
Extreme heat exacerbated by the climate crisis is intensifying the drought hitting the continent as record-breaking heatwaves means the hot atmosphere is evaporating water from rivers, lakes, soils and plants quickly.
The Danube has hit the lowest level of water in 30 years in several countries including Hungary, Serbia and Romania, and the Rhine has dropped to its lowest recorded level in some sections and is expected to drop further due to drought
Conservation projects often focus on protecting a threatened species from predators and habitat destruction. But as our research shows, restoring food webs can be as important to supporting ongoing recovery.
This may require ecological restoration of several sites that connect an endangered species with its food.
Our recent study focused on Waituna Lagoon, a site in the South Island long recognised under the Ramsar Convention for its outstanding biodiversity values as an internationally important wetland area.
The research demonstrates the lagoon’s significance as an important food source for longfin eels, which are classified as at risk, with declining populations.
The lagoon is formed by a barrier beach. When it overflows this barrier, either naturally or through excavation, it remains open to the sea until big swells block the opening again. This can take anywhere between a month and a year.
During the open state, ?nanga – small migratory native fish which form the majority of whitebait – run freely from the ocean and become extremely abundant.
This supercharges the wider catchment’s food web, including eel populations living upstream in surrounding creeks.
How ?nanga support eel growth
The duration of open conditions varies between years, and so does the abundance of ?nanga. We think of this as a “natural experiment” that manipulates food supply. Our study shows how important changes in ?nanga abundance are for longfin eels.
We analysed a small set of otoliths (fish “ear” bones) collected from local iwi (tribal groups). Otoliths have annual rings that record age and growth rates in much the same way as tree rings.
We found that during open years, Waituna Creek eels grew faster than during closed years when ?nanga were scarce, confirming the key role ?nanga play as a prey fish.
Large ?nanga runs boosted the abundance of eels in the catchment to far higher levels than typically occur in coastal streams that don’t have large downstream wetlands.
Our findings are significant because New Zealand’s main eel conservation strategy is to protect eels from fishing within the conservation estate. However, the Waituna Creek produces almost ten times the biomass of eels per year and kilometre of stream length than streams within the conservation estate (on average).
The value of growing big eels
Boosting eel growth is a critical lever for eel conservation. Having bigger, faster growing and more abundant eels in steams means more females reach their spawning grounds in the equatorial Pacific Ocean.
Eels return from their spawning grounds as tiny leaf-shaped and transparent juveniles. The journey back into rivers is perilous and the more females make it to the spawning grounds, the more juveniles will be returning to Aotearoa.
A single four-kilogramme longfin eel can produce around eight million eggs, whereas a female of half that weight may only produce about two million eggs.
Creating landscapes rich in wetlands that provide lots of high quality, energy-dense food in the form of ?nanga can help eels reach a larger size and better support the New Zealand-wide population.
Wetlands support wider ecological restoration
Understanding how wetlands benefit the wider surrounding landscape opens a new avenue for ecological restoration. This includes protecting and creating food-producing habitats which then disperse the benefits throughout a catchment.
Previously, if a project’s goal was to enhance biodiversity in a particular location, it usually focused on that site. But our research suggests it might in fact be better to focus restoration efforts on adjacent sites that produce a food source to improve ecological conditions for a threatened species.
In our study, the goal was to improve conditions for eels living in a lowland agricultural stream with elevated nutrients, little riparian planting and an engineered channel designed for convey flood waters with little consideration for fish habitat.
At Waituna Creek, the biomass of longfin eels more than doubled two years after efforts to restore the stream through riparian planting and creating woody habitat in the stream channel. But the restoration was successful because the eels had enough food in the form of ?nanga swimming upstream from the wetland to support the population increase.
We are increasingly appreciating the ecological role of wetlands as we recognise their value as critical natural infrastructure that slows down water to prevent flooding, locks up carbon and traps sediment and nutrients. Now our study shows they are also hotspots that can fuel fish growth in distant sites through connected systems.
The recently completed Jobs for Nature programme restored more than 6,000 hectares of wetland. It will be exciting to see the benefits of this work transferring through to native fishes.
Protecting wetlands doesn’t just preserve the plants that live there. It protects highly valued predatory fish and bird species in connected systems.
Simon Stewart receives funding from Te Ap?rangi Royal Society of New Zealand and the Ministry of Business, Innovation and Employment's Endeavour Fund. Earlier aspects of this research were funded by Dairy NZ and the Department of Conservation through the Living Waters programme.
Robin Holmes receives funding from the Ministry of Business, Innovation and Employment's Endeavour Fund. Earlier aspects of this research were funded by Dairy NZ and the Department of Conservation through the Living Waters programme.
In late June, whale watchers in southwest Western Australia sounded the alarm. They had seen far fewer humpback whales at a time when they normally migrate up from the Southern Ocean to calve and feed. Numbers were 60% below normal.
A week later, birdwatchers spotted a “once in a lifetime event” as large numbers of rarely seen albatrosses and petrels appeared off Australia’s east coast, thousands of kilometres from their usual foraging grounds deep in the Southern Ocean. Many birds were in poor condition.
The sightings came just weeks after a dying migratory seabird was confirmed as Australia’s first case of highly pathogenic H5N1 bird flu.
These sightings raise troubling questions. Seabirds and marine mammals such as whales use ocean currents and weather to travel long distances to feeding and breeding grounds. If these species are changing their behaviour, it could be a sign of altered conditions in the Southern Ocean.
We know the world’s oceans are running very hot. Marine heatwaves can affect any part of the ocean – even frigid Antarctic regions. If species are used to water temperatures around 2–6°C, a sudden boost of a couple of degrees can upend ecosystems. If the heatwave lingers, the cumulative effect can be much bigger.
We don’t yet know for sure, as monitoring in the Southern Ocean is limited. But we know marine heatwaves can alter currents, weather conditions and prey availability.
Oceans running hot
Since February, a large and persistent marine heatwave has affected waters around Australia’s Heard Island and McDonald Islands, stretching as far south as the edge of Antartica’s sea ice. These remote islands are extraordinarily rich in life. But researchers have found their waters are exposed to damage from climate change.
A long-lasting marine heatwave is affecting the Southern Indian Ocean, as shown in these monthly averaged temperature anomalies. Heard Island is roughly in the center of the image.Chris Chapman/NOAA-OISST, CC BY-NC-ND
The southern Tasman Sea has also endured a marine heatwave since at least April, likely due to the fact we are coming out of successive La Niñas.
Both areas of ocean are among the fastest-warming on the planet. The steady drumbeat of climate change can make marine heatwaves more severe, more frequent and longer-lasting.
It’s possible this marine heatwave is putting pressure on seabird and whale food supply. But there remain significant gaps in our knowledge.
One reason is that extreme events don’t occur very often. Given this, it’s worth looking at past events.
Devastation from ‘the Blob’
Between 2014 and 2016, the North Pacific Ocean was hit by an event scarier than any monster movie.
A huge, long-lasting and extreme marine heatwave stayed in place for many months. It became known as “the Blob”.
Water temperatures were between 2°C and 6°C above normal. While this may not seem like a drastic change, it led to widespread ecosystem disruption. At least 240 species were found outside their normal ranges – some further north than ever recorded.
It’s hard to overstate how extensive its effects were. Kelp forests disappeared. Millions of starfish dissolved into goo. Whales died. Seabirds starved. Toxic algal blooms appeared.
It’s possible reported falls in whale numbers and unusual sightings of seabirds might be linked to a smaller version of the Blob in the cold Southern Ocean.
We already know marine heatwaves can disrupt the feeding behaviour of marine predators such as little penguins in Tasmania.
Our research has shown marine heatwaves lead to significant shifts in the types of zooplankton – tiny floating animals – found in coastal seas off Tasmania. Zooplankton are important food sources for seabirds, whales and fish.
As early as 1997–98, researchers found warmer surface waters in the Southern Ocean made it harder for female Antarctic fur seals to find prey while raising their pups.
Deaths of pups and adults are becoming more common in the South Atlantic. The population has fallen by around 1.5 million in the 15 years to 2022. The species was once considered abundant. But it’s now has recently listed as endangered.
We don’t know what we don’t know
By studying past events, scientists now have a better understanding of how marine ecosystems respond to extreme events.
Even so, there’s a lot we don’t know. For example, we have strong evidence climate change is affecting Antarctic krill. But we still don’t fully understand how a particular marine heatwave affects these tiny crustaceans or how ocean predators such as whales and seabirds respond during such events.
In short, our knowledge of how extreme events affect ecosystems isn’t keeping pace with climate change.
For scientists to understand how vulnerable species respond to environmental triggers, we need to monitor key species over the long term, while tracking environmental conditions in breeding and foraging areas and their food sources.
This type of monitoring is expensive, time-consuming and challenging. It would require national coordination, international collaboration and sustained support. But if we want to understand what’s driving ecosystem changes affecting local and migratory species in our waters, it will be necessary.
Once up and running, these dynamic monitoring systems would help authorities respond quickly by, say, reducing or redirecting fishing boats if there’s a sudden drop in fish numbers. Monitoring would also show areas in need of better protection.
We know changes are taking place in these cold oceans. Fewer whales and rare seabird sightings are a warning sign. If we don’t have better monitoring, we will keep flying blind as global warming accelerates.
Mary-Anne Lea has received funding from the Australian Research Council, the Australian government, international agencies and others. She is affiliated with the University of Tasmania, the Scientific Committee on Antarctic Research (SCAR) Expert Group on Birds and Marine Mammals, the SCAR Standing Committee on the Antarctic Treaty System (as a delegate to CCAMLR), the IUCN World Congress on Protected Areas, Marine Mammal Protected Areas Taskforce and is a co-founder and Board director of Homeward Bound Projects.
Christopher Chapman has received funding from Parks Australia and the National Environmental Science Program's (NESP) Climate Systems hub.
What’s the best way to manage a forest? Australians have argued about this for decades. The debate is often framed as binary: do we protect forests entirely, or harvest trees to support local economies and communities?
The reality is more interesting, as our new research on a long-forgotten experiment in Victoria’s mountain ash forests reveals.
Since the 1970s, scientists and the public have questioned the use of clearfell logging – where all trees in a block of forest are cut down. Conservationists argued it destroys habitat for rare species and reduces the forests’ ecological value. Foresters said mountain ash is adapted to catastrophic bushfires, and clearfelling is the forestry equivalent.
The argument was heated and the polarisation unhelpful. But the underlying questions about the impacts of clearfelling, and how they compared to less intensive forestry options, remained unresolved.
Aerial views of the Tanjil Bren Silvicultural Systems Project. L: Small cleared patches varying in size (50-140 metres wide) and shape (square vs. rectangular) R: Heavy thinning.Centre for Forest Tree Technology.
A landmark experiment
In the mid-1980s, the Victorian government launched a major restructure of the timber industry, and invested today’s equivalent of A$26 million to explore alternatives to clearfelling. This would use silviculture, the branch of forestry that deals with establishing, growing and tending forests.
The Silvicultural Systems Project was established at two sites between 1987 and 1989: Tanjil Bren in Victoria’s Central Highlands, and Cabbage Tree Creek in East Gippsland.
It was a landmark experiment, comparing forest regeneration across the full range of silvicultural approaches. These included traditional clearfells (250–350 metres wide), small patch clearfells (50–140m wide), and heavy thinnings, where 50–70% of trees were cut. Extensive areas of unharvested forest were kept as benchmarks for comparison.
The forest at Tanjil Bren was dense mountain ash regrowth from the 1939 fires. Hundreds of survey plots were established and thousands of seedlings were monitored. By the early 2000s, the results were clear: mountain ash regenerated best on clearfell sites. Where tall canopy trees were retained or the cleared patches were small, common understory species such as acacia dominated.
The findings were published. The access road grew over. The project sign collapsed. The experiment was forgotten. The debates continued.
But the trees kept growing.
L: The Silvicultural Systems Project (SSP) sign at Tanjil Bren in the late 1980s. R: the sign rescued from the forest floor in 2025.Centre for Forest Tree Technology/Tom Fairman
Astounding results
In 2014 we visited the Tanjil Bren site as part of a University of Melbourne subject on silviculture in native forests. A colleague, Simon Murphy, had been involved in its establishment and suggested our students see the long-term outcomes of different silvicultural systems side-by-side. What we found was astounding.
The original results still held: 30 years later, the mountain ash in the large cleared patches and clearfelled areas was vigorous and abundant. But it was the heavily thinned parts of the forest that really caught our attention.
The trees left behind after thinning were enormous. While they were only 80 years old, the largest averaged well over a metre in diameter at chest height, and some were more than 1.5m. Thinning had given these trees more space and resources to grow, and they had responded dramatically. The largest trees in the thinned stands were 20% bigger in diameter than those in the unharvested control areas.
More remarkable still: the thinned stands of trees had stored as much or more carbon in their wood than the unharvested control areas. In just 30 years, the heavily thinned forest had not only recovered all the carbon removed during harvesting, but had also gained enough additional carbon to equal the increase seen in the unharvested controls.
These findings have profound implications. Bigger trees are more resistant to fires, so when the next fire occurs, they are more likely to survive. Bigger trees are also more likely to form hollows – a critical and declining habitat for rare species such as the greater glider and Leadbeater’s possum.
The acacia trees that grew in most of the silvicultural treatments are also vital for Leadbeater’s possums, which use it to forage and move around the forest. Camera traps across the sites confirmed this: Leadbeater’s possums were found in every silvicultural treatment plot we surveyed – but none of the unharvested areas.
A Leadbeater’s possum in one of the heavily thinned sites 33 years after the silvicultural treatment.Jeremy Johnson
Lessons for the future
The Tanjil Bren SSP offers three important lessons.
First, long-term silvicultural experiments are irreplaceable. Australia’s forests contain many forgotten experiments that could transform our understanding of how forests respond to human intervention. But all too often, they end up neglected, unfunded and forgotten. We should find them before it is too late.
Second, forest thinning is not a trade-off. Our findings show this for mountain ash, and other studies in North America have shown this for conifer forests. It can deliver wood for local industry, absorb carbon and improve habitat for wildlife. It is a win-win-win outcome that challenges the false dichotomy of conservation versus production that has dominated public debate for decades.
While thinning cannot (and should not) be done everywhere, it may be a useful tool to create more variety in tree ages and sizes, particularly in forests impacted by clearfelling or high-severity fire.
Third, and perhaps most importantly: there is no silvicultural silver bullet for managing forests. The long-forgotten experiment at Tanjil Bren has taught us that there are options available for managing our forests beyond clearfelling that can contribute to the societal demand for wood, maintain carbon stocks, and conserve biodiversity.
Craig Nitschke receives funding from the Australian Research Council (DP22010371), State Government of Victoria's Department of Energy, Environment and Climate Action, Australian Forest and Wood Innovations (AFWI), New South Wales Department of Primary Industries and Regional Development – Local Land Services, NSW Natural Resources Commission, Greening Australia, Natural Hazards Research Australia, North Central Catchment Management Authority (CMA), Northeast CMA, Goulburn Broken CMA.
He also receives funding from commercial companies Radial Timber Australia and Heartwood Unlimited for separate research unrelated to the study described in this article. Neither company would benefit or profit from any of the results associated with the research described in this piece.
Patrick Baker receives funding from Australian Forest and Wood Innovations (AFWI), the Australian Centre for International Agricultural Research (ACIAR), and the Australian Research Council (ARC).
Raphael Trouve receives funding from the Australian Research Council (ARC).
Kaitlyn Hammond does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.
