Floods are New Zealand’s most frequent disaster, and one of the most costly. But regions have varying abilities to predict floods depending on local councils’ ability to buy weather data. And though that data is publicly funded, scientists who have created a national flood-forecasting system cannot put it into practice without free access to the same information. Should we prioritise profitability of our research institutes, or public safety?
A new study reveals that New Zealand’s huge ocean territory contains two billion tons of carbon, locked in the seafloor. If we want to fight climate change, it might be a good idea to keep it there.
For almost 25 years, marine biologist Vreni Häussermann has been opening people’s eyes to the wonders of the Chilean Patagonia fjords and using her research to push for greater protection of the marine environment.
Two scientists mapping New Zealand’s light pollution have found our nights became a lot brighter over the past decade—and that most of our public lighting is now bright blue-white light-emitting diodes (LEDs) which negatively affect human and animal health. Te Pūkenga Nelson Marlborough Institute of Technology ecologist Ellen Cieraad and wildlife biologist Bridgette Farnworth used satellite data to map New Zealand’s light pollution and found it grew by 37.4 per cent from 2012 to 2021. That’s faster than the global average. Using the Official Information Act, they also found most councils used millions of dollars of Waka Kotahi funding to replace streetlights with LEDs—but at least 77 per cent of those are cool, blue-white LEDs with a colour temperature of 4000 kelvin (K), shown to affect human circadian rhythms and wildlife. In a paper recently published in the New Zealand Journal of Zoology, bat scientists experimented with 4000K LED floodlights illuminating trees at a Tamahere home, discovering that local critically endangered long-tailed bats avoided the area when lit. That’s contrary to a popular theory that night-time light attracts insects, which attract bats. In humans, circadian rhythm disruption has been implicated in cancer, obesity, diabetes, depression and sleep disorders, and possibly increases the risk for dementia. [caption id="attachment_493565" align="alignnone" width="1600"] Councils rapidly adopted LED streetlights. Trace each "stream" to see a region's journey: Waimate, for example, only started installing them in 2020 yet by 2021, all of its streetlights were LEDs. Ashburton, on the other hand, started the process in 2000 and is now sitting at 83 per cent.[/caption] The International Dark Sky Association recommends lights should be 3000K or less; some European countries don’t allow anything over this. A few councils in New Zealand are light-savvy, too. Kaikōura, for example, recently installed dimmable 3000K and 2200K LEDs to help protect the light-sensitive Hutton’s shearwater, which kept crash-landing in town. But the default was 4000K, says Cieraad. If councils wanted a different temperature of outdoor lighting, they faced extra difficulties to obtain it. “So most councils didn’t.” It’s bad news for dark-sky scientists and enthusiasts, who long ago realised the plethora of cheap LEDs is threatening the natural night already lost in so many places around the world. A petition to legislate against light pollution, spearheaded by University of Canterbury emeritus astronomy professor John Hearnshaw, is now before a select committee. But most councils have now spent more than $150 million installing lights that interrupt our circadian rhythms and dazzle wildlife—lights that are too much like daylight for the night under which we evolved. They will be in place for some time. It’s frustrating, but Cieraad is optimistic. Public lighting makes up only about a fifth of light pollution, so there is space for businesses and citizens to be more thoughtful. We can buy less intense lights, or use dimmer switches and motion sensors, or shields that direct light downwards. Or, of course, the off switch.
Giselle Clarkson, Gecko Press, $39.99
Gina Moseley is unearthing secrets about our climate in some of the world’s most remote caves.
The sea ice around Antarctica melts and refreezes with the seasons, usually doubling the size of the continent by the end of winter. For most of 2023, about two million square kilometres has been missing in action—a record low. We’ve only been keeping satellite records of sea ice for 44 years, but the extent of the melt is “an alarming drop off the cliff” and very unlikely to be natural variability, says NIWA’s Natalie Robinson. “We’re essentially missing between seven and 10 New Zealands’ worth of sea ice.” Some Australian researchers have even suggested the Southern Ocean is entering a new state of lower ice levels—a so-called “regime shift” with worldwide flow-on effects. Sea ice reflects heat and absorbs carbon dioxide from the atmosphere. It controls how oceans distribute warmth, nutrients and oxygen across the planet. And the ice provides crucial habitat—from the algae and krill that live underneath and form the basis of the marine food chain to the penguins and seals that breed on its surface. New Zealand is one of the closest nations to Antarctica, and our climate is strongly influenced by the Southern Ocean, says Craig Stevens, also from NIWA. “Some of these effects will be felt here first.”
New Zealand and Nepal share a close connection, largely through the work of Sir Edmund Hillary, Tenzing Norgay and their families. But for Rinzin Phunkjok Lama there’s a different connection to New Zealand that has had a huge impact on his life - and on the wildlife of his home country.
Few native New Zealand plants produce a sweet and tasty fruit that you can pick and eat straight away. Pātōtara, a prickly, low-growing shrub, is one of them. Its juicy yellow-orange berries, about the size of currants and tasting like apricots, were once a popular sweet treat for children. The heath-like shrub spreads laterally, often forming quite dense stands of upright stems up to about 15 centimetres tall. The leaves have a hard texture and a tip that narrows to a fine, sharp point that can be prickly to touch. It’s common in dryland sites at all altitudes throughout Aotearoa, ranging from coastal sand dunes at sea level to rocky outcrops, low tussock grasslands and sub-alpine herb fields. Pātōtara has a long flowering season, from September to January, with flowers and fruit appearing at the same time, and fruit ripening from February through to April. Its white, tubular flowers have a strong honey scent. When the plant was more plentiful, its fragrance filled whole alpine valleys; with an offshore wind, it was apparently perceptible to mariners at sea—even before land was within sight. In Traditional Lifeways of the Southern Māori, Herries Beattie’s informants told him the kiore/native rat, weka, and even the koreke/extinct native quail relied on a diet of berries from native plants, including pātōtara. This plant also features in a number of recipes for traditional Māori perfumes and scents, including an oil to anoint bodies before burial. In this recipe, the root of the pātōtara was carefully scraped and smelled like cloves, according to one source in Murdoch Riley’s Māori Healing and Herbal. Medicinally, crushed leaves of pātōtara, mānuka, tarata and kawakawa were mixed with taramea gum and oil from kōhia/New Zealand passionfruit seeds to make a scented oil to treat chronic aches and pains. Excerpted from Treasures of Tāne: Plants of Ngāi Tahu by Rob Tipa (Huia Publishers).
Of all the species living on Earth, perhaps two-thirds of them live in the dirt under your feet, according to a group of Swiss scientists who set out to make an educated guess on the matter. Obviously, it isn’t possible to count everything in the soil everywhere on Earth. The scientists’ estimate is built on multiple estimates made by other groups of researchers. The Swiss trio looked at the entire tree of life—they wanted to know how many bacteria and viruses lived in the soil as well as how many plants, worms, bugs and fungi. Viruses were particularly hard to measure, because viruses aren’t categorised as species, like plants and animals are. Instead, the researchers decided that viruses with sufficiently different DNA or RNA would count as different species. What’s the point of making such a guess, if it’s just a guess? We know that dirt is the basis of life on Earth, and that it even has an impact on human health—previous research has shown that the soil microbiome and human microbiome are connected. That means it’s useful to have a big-picture idea of what lives down below.
After three warm, wet La Niña summers in a row, El Niño is coming. The climate pattern is well known for its effect on New Zealand’s weather, but what will it mean for the sea? Marine heatwaves have plagued our oceans since 2020. In some places, sea temperatures spiked by five degrees. Tens of millions of sponges bleached in Fiordland and 1300 tonnes of farmed salmon died in the Marlborough Sounds. This July, winter sea temperatures around Rakiura Stewart Island remained more than four degrees above average. El Niño may bring some respite, says NIWA oceanographer Erik Behrens. Whereas La Niña winds tend northeasterly, shuttling warm air down from the tropics and heating the surface of the ocean, El Niño usually brings strong westerlies and southwesterlies. Colder winds over warm oceans make the water column unstable, mixing cool water from underneath with that on the surface, dissipating built-up heat. “We will still see heatwaves, but they shouldn’t be as intense,” says Behrens. Still, southerly winds battered the South Island this winter, yet the marine heatwaves remained. “You’d expect a few good southerlies to stand up the oceans and make [the heatwaves] vanish,” says Behrens. That they didn’t suggests the ocean is overwarm all the way down, he says—holding a “memory” of three scorching years.
New data released by Stats NZ suggest Aotearoa has turned a corner in greenhouse gas emissions, reducing from a pre-pandemic peak of 21 million tonnes in March 2019 to 18.4 million tonnes in December last year. But the story for each industry sector is a little more complex than the total might suggest. Both mining and commercial transport emissions have increased, while an economic slowdown has led to reductions in agriculture, forestry, fishing and manufacturing. Record rainfall teamed with new solar and wind generation has meant our energy sector has been flush with renewable power—rather than importing and burning coal—resulting in a whopping reduction of 1.7 million tonnes of emissions. So has New Zealand really turned a corner? Can we sustain these lower numbers? The graph suggests it’s possible. In the COVID-19 lockdown of 2020, emissions plummeted from 21 to 18.3 million tonnes, then rebounded to 20 million within months, but the trendline since 2019 describes a long downward ramp—not yet fast enough to meet our climate goals and obligations, but heading in the right direction nonetheless.
Many of the world’s oceans are greener than they were 20 years ago, a new study published in Nature has found—suggesting climate change is altering sea-surface ecosystems. A single satellite orbiting the Earth for the past two decades has been keeping tabs on the colour of the oceans by measuring the way different wavelengths of light reflect from its surface. Scientists had thought we’d need many more years of data before signs of climate change would show up in this way, but by looking at seven light wavelengths, the researchers found that more than half of the oceans worldwide have significantly altered in hue— especially in temperate and tropical areas—and that the shift can’t be explained by natural variability. What’s causing the deviation isn’t yet clear, but it likely has something to do with the interaction between warming waters, ocean nutrients and phytoplankton—tiny aquatic plants that contain the green pigment chlorophyll. Changes in plankton communities on such a vast, global scale have implications for ocean carbon storage, food webs and fisheries, the study authors say, meaning the switch from blue to green could be an early-warning signal of wider shifts.
Lines on a map have led to countless conflicts over the centuries. But in Chad, Hindou Oumarou Ibrahim, an environmental activist and defender of the rights of Indigenous Peoples, is using maps to try and avoid conflicts that are being exacerbated by the impacts of climate change.
After 23 years, we have made the first tangible step towards recovery of the Hauraki Gulf.
New Zealand Geographic and Heritage Expeditions invite readers to experience some of New Zealand’s most remote southern shores on our next special voyage. Departing on March 1 2024, the eight-day itinerary combines three amazing destinations - Stewart Island, Fiordland and The Snares - into one journey, with ex-director general of DoC and renowned conservationist Lou Sanson joining as our onboard expert.
Scientists fear that the world's coral reefs could disappear if we don't do enough to reduce our impact on the oceans. But Dr Emma Camp sees a glimmer of hope in super-resilient corals that are able to withstand higher temperatures, greater acidification and lower oxygen levels and her research has shown that they could play an important role in reef preservation.
Southern right whale calves are born right here at the Auckland Islands, during winter, and weigh in at a tonne on day one. The calf will remain with its mother for up to two years, at which time it will have doubled in length.
Scientists gather the day’s samples in the cosy saloon of the expedition ship Evohe. Every sample tells a story, but first you need to extract it from the dart. But the blubber can only tell you so much—the scientists also rely on data from drones to build three-dimensional models of the whales, satellite tags to trace their migration, and scoops of poo to understand what they’re eating.
Scientist Emma Carrol is trying to understand the population dynamics of the southern right whales that over-winter at the Auckland Islands—how are they related to each other, how many there are, and where they travel over summer. Using a biopsy dart she can capture a plug of blubber about the size of a pea from an individual which reveals it’s DNA to unravel some of these mysteries.
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