Geoengineering: what is it and why is the UK funding trials

The UK is putting tens of millions of dollars into trials for the technique known as geoengineering - intervening in nature in an attempt to slow climate change. The funding will support trials in marine cloud brightening and stratospheric aerosol injection, which aim to reflect sunlight or absorb carbon dioxide to cool the planet. Officials say the move is out of concern that emission reduction efforts may not be enough to avert dangerous climate tipping points. However, critics warn that geoengineering could have unpredictable side effects, potentially altering weather patterns and diverting attention from emissions cuts. Damian Carrington is The Guardian's environment editor.
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RNZ News

4 days ago

• RNZ News

Scientists may have found a big, mysterious carbon sink in the South Island

Fiordland forest. Photo: Supplied / James Williams, NIWA Scientists may have found a big, mysterious carbon sink in the South Island. But they caution more work is needed to solve the puzzle before New Zealand could claim the discovery as a climate win. NIWA scientists have suggested the reason might be that native forests in the South Island are capturing much more carbon than previously thought, which could pave the way for New Zealand to use pest control and other conservation efforts to boost forest health and help meet the country's climate targets. The study leader, NIWA atmospheric scientist Beata Bukosa, said researchers first need to resolve the mystery of where tens of millions of tonnes of seemingly disappearing carbon dioxide are going to. The carbon sink was found over parts of the south west South Island dominated by mature native forests, including Fiordland. "The next thing we have to do is really identify the exact process responsible for this carbon uptake and figure out where the carbon goes," Bukosa said. "At the moment, with our methods we can see the signal that the carbon is basically disappearing in that region but we can't identify where exactly that carbon goes and what is happening after it disappears." The study uses a different technique from the official estimates used in New Zealand's official greenhouse gas inventory. The official inventory uses a variety of methods, including so-called "ground up" estimates of natural carbon storage based on real measurements of trees growing in our native forests. For the latest study, scientists from several universities and research institutes analysed carbon dioxide measurements taken between 2011 and 2020 from Wellington's Baring Head and Lauder research station in Central Otago and used modelling to work out how that carbon dioxide was being transported. Beata Bukosa. Photo: Supplied / Lana Young They found much more carbon was disappearing than other methods had suggested -- around 50-140 million tonnes a year more than the previous estimates, or between one and three years' worth of all New Zealand's carbon dioxide emissions from human activities. Bukosa said they expected to get different results from using different methods, but the differences they found were bigger than could be explained by varying calculation methods. "You would expect some difference just from the way the methods there was still a stronger [carbon] sink in our estimates," she said. "Earlier estimates of how much carbon was removed by New Zealand land ecosystems ranged from a net 24 to 118 million tonnes a year. "Our research found that New Zealand's natural environment absorbed approximately 171 million tonnes of CO2 annually." As for what was behind the difference, she said the south west South Island location suggested it could be native forests but it could also be something less beneficial to nature and the climate, such as rain or landslides carrying soil - and the carbon it contains - down rivers and away from New Zealand, to be released somewhere else. "That's the crucial question we are trying to answer at the moment," said Bukosa. "The region where we found the biggest difference and the strongest sink is around Fiordland and the southwest coast of the South Island and these are also regions where we have quite a bit of erosion, which could lead to frequent landslides which transports carbon. "The forest might be behaving differently due to climate change, or even regenerating due to pest control. We need to add up all the numbers and see how it is contributing." If native forests are capturing much more carbon than previously thought, it could pave the way for New Zealand to use pest control and other conservation efforts to help meet its climate targets and boost the health of native species. Separate studies are tracking the impacts of pest control on boosting carbon storage in native forests in the South island and the East Coast of the North Island. "Depending what the answer is, that could open up new doors on how to mitigate climate change and potentially reduce our reliance in international carbon credits," Bukosa said. The research grew from a 2017 pilot study suggesting native forests in Fiordland and other parts of southwest New Zealand might be sequestering up to 60 per cent more carbon dioxide from the atmosphere than expected. Bukosa said the latest study extended the period analysed from three to 10 years and improved the atmospheric modelling used. "The results basically confirmed what we saw in 2017 as well, which is that it seems like there is more carbon dioxide being absorbed across New Zealand relative to what we thought before." Previous estimates used by the Ministry for the Environment and others to create the country's official greenhouse gas estimates say native forests are overall almost carbon neutral - releasing about as much carbon overall as they absorb. But those figures are uncertain, with some forests losing carbon and some forests gaining. Bukosa said previous studies may have underestimated the amount of carbon taken up by mature indigenous forests. Dr Andrea Brandon of the Ministry for the Environment was also involved in the study. She said the findings "indicate there may be additional carbon uptake somewhere in the system that we are currently not tracking. We need to identify what we are missing so that we can further refine our Inventory methods to capture it." As well as Brandon, the NIWA scientists worked with researchers from GNS Science, Manaaki Whenua, the University of Waikato and overseas as part of a Ministry for Business, Innovation and Employment-funded Endeavour programme called CarbonWatch NZ, which ended last year. Sign up for Ngā Pitopito Kōrero , a daily newsletter curated by our editors and delivered straight to your inbox every weekday.

RNZ News

11-06-2025

• RNZ News

Fieldays: Farmers expected to come on board as methane science advances

Prime Minister Christopher Luxon at the Science for Farmers tent at Fieldays. Photo: Eloise Gibson The Prime Minister's new chief science adviser believes farmers will come around to technologies that cut their emissions. Some farming groups oppose inventions like methane vaccines, but John Roche says farmers will accept change once they see the products work. For a long time, one of the main concerns for farmers about tackling climate change was the lack of new technologies to lower emissions, without hurting productivity. Prime Minister Christopher Luxon listen to a speech in the Farmers for Science tent. Photo: RNZ / Eloise Gibson Now emissions-cutting products are close to being launched, and some farmers are saying they don't want them. Groups such as Beef + Lamb say methane emissions shouldn't be priced because it would force farmers to use products such as methane vaccines and other technology when they shouldn't have to. Groundswell recently released a survey saying its members did not want to use methane-cutting products (called inhibitors) and didn't believe action on emissions should affect their access to overseas markets. Fonterra, by contrast, has signed up to reduce dairy emissions to secure what it says are higher value exports to customers such as Nestlé. Roche said although there was a noisy segment that still needed a little convincing he was confident most farmers will come round. "New Zealand farmers have always adopted technologies that improve their efficiency, that improve the saleability of their products," he said. "I think it will be the same here, and they will adopt the technologies as they come on board, as they become more affordable and importantly as they see other farmers use them and see that they work." Roche splits his time between his new role as Christopher Luxon's chief science adviser and being the chief science advisor for the Ministry for Primary Industries. John Roche has a split role. Photo: Supplied He helped arrange a tent called Science for Farmers at Fieldays, where farmers could speak to researchers working on scientific innovations, including emissions-cutting products. One stall housed rectangular planter boxes of lush pasture - not your typical ryegrass and clover, but diverse mixtures of up to seven species including the herb plantain. Danny Donaghy from Massey University said these pasture mixtures should better withstand droughts and/or floods, and contribute less to the problem of global heating by releasing less nitrous oxide from the soil and methane from the animals that eat them. Research funding group the Ag Emissions Centre was also there, sharing research showing dairy cow daughters inherit low-methane traits from their fathers. It said that paved the way for lower-methane breeding bulls from late 2026. Less advanced, but moving quickly, was Lucidome Bio's methane vaccine, currently being trialled in Palmerston North. Chief executive David Aitken said the company was aiming for a 20-30 percent reduction in methane from sheep and cattle lasting for about six months - and to have it on farms within five years. "The vaccine stimulates antibodies in the saliva of the ruminant. The antibodies are then transported into the rumen, where they bind onto the methanogens that produce methane, inhibit the growth and reduce the amount of methane." Over time the company hopes to get a productivity gain from the vaccine, since methanogens steal some of the animal's energy. "But at the minimum we are looking at a solution that's neutral on productivity so we get the climate benefits without losing profitability or productivity." At another stall in the tent, farm software company FarmIQ was explaining how its software can estimate changes in profits, production and emissions from changing various aspects of a farm. Chief executive Gavin McEwen said farmers can already reduce emissions by one to five percent through measures like using less nitrogen fertiliser and reducing stocking rates, often without sacrificing production. But bigger-hitting technologies are coming soon, like slow-release boluses that animals swallow to lower emissions. Head of sales Russell MacKay, a fifth generation farmer, says good financial times should help farmers buy new climate tech. "When the farmers are making money that means there more cash more money for fencing off waterways and bringing in new technology to help the environment."

RNZ News

11-06-2025

• RNZ News

Emperor penguin populations in Antarctica declining faster than expected

Photo: AFP / Biosphoto By Kelly Macnamara , AFP Emperor penguin populations in Antarctica have shrunk by almost a quarter as global warming transforms their icy habitat, according to new research on Tuesday that warned the losses were far worse than previously imagined. Scientists monitoring the world's largest penguin species used satellites to assess sixteen colonies in the Antarctic Peninsula, Weddell Sea and Bellingshausen Sea, representing nearly a third of the global emperor penguin population. What they found was "probably about 50-percent worse" than even the most pessimistic estimate of current populations using computer modelling, said Peter Fretwell, who tracks wildlife from space at the British Antarctic Survey (BAS). Researchers know that climate change is driving the losses but the speed of the declines is a particular cause for alarm. The study, published in the journal Nature Communications: Earth & Environment , found that numbers declined 22 percent in the 15 years to 2024 for the colonies monitored. This compares with an earlier estimate of a 9.5-percent reduction across Antarctica as a whole between 2009 and 2018. Warming is thinning and destabilising the ice under the penguins' feet in their breeding grounds. In recent years some colonies have lost all their chicks because the ice has given way beneath them, plunging hatchlings into the sea before they were old enough to cope with the freezing ocean. Fretwell said the new research suggests penguin numbers have been declining since the monitoring began in 2009. That is even before global warming was having a major impact on the sea ice, which forms over open water adjacent to land in the region. But he said the culprit is still likely to be climate change, with warming driving other challenges for the penguins, such as higher rainfall or increasing encroachment from predators. "Emperor penguins are probably the most clear-cut example of where climate change is really showing its effect," Fretwell told AFP. "There's no fishing. There's no habitat destruction. There's no pollution which is causing their populations to decline. "It's just the temperatures in the ice on which they breed and live, and that's really climate change." Some colonies have lost all their chicks in recent years because the ice has given way beneath them. Photo: AFP / Biosphoto Emperor penguins, aka Aptenodytes forsteri, number about a quarter of a million breeding pairs, all in Antarctica, according to a 2020 study. A baby emperor penguin emerges from an egg kept warm in winter by a male, while the female in a breeding pair embarks on a two-month fishing expedition. When she returns to the colony, she feeds the hatchling by regurgitating and then both parents take turns to forage. To survive on their own, chicks must develop waterproof feathers, a process that typically starts in mid-December. The new research uses high-resolution satellite imagery during the months of October and November, before the region is plunged into winter darkness. Fretwell said future research could use other types of satellite monitoring, like radar or thermal imaging, to capture populations in the darker months, as well as expand to the other colonies. "We really do need to look at the rest of the population to see if this worrying result transfers around the continent," he said, adding however that the colonies studied were considered representative. He said there is hope that the penguins may go further south to colder regions in the future but added that it is not clear "how long they're going to last out there". Computer models have projected that the species will be near extinction by the end of the century if humans do not slash their planet-heating emissions. The latest study suggests the picture could be even worse. "We may have to rethink those models now with this new data," said Fretwell. But he stressed there was still time to reduce the threat to the penguins. "We've got this really depressing picture of climate change and falling populations even faster than we thought but it's not too late," he said. "We're probably going to lose a lot of emperor penguins along the way but if people do change, and if we do reduce or turn around our climate emissions, then then we will save the emperor penguin." - AFP