Our Changing World

GNS Science is measuring how much carbon dioxide we're producing in different towns as part of the Carbon Watch NZ project.

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Fifty years ago Dave Lowe started measuring carbon dioxide in New Zealand's atmosphere. And Gordon Brailsford and Sara Mikaloff Fletcher talk about Carbon Watch NZ project.

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Dave Lowe on measuring CO2 in New Zealand for 50 years, and how Carbon Watch NZ is a bird's eye view on our carbon balance.

Carbon Watch NZ is a collaborative project to measure our greenhouse gases - where they are coming from and where they are going to.

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When it comes to greenhouse gases in the atmosphere, the biggest culprit is carbon dioxide (CO2) - and it's something that New Zealand has been interested in for a long time.

New Zealand is home to the longest running continuous carbon dioxide measurements in the southern hemisphere, second only to Hawaii in the northern hemisphere.

Measurements began here fifty years ago, initially at Makara, near Wellington. They were set up by atmospheric scientist Dave Lowe, who worked for many years at NIWA.

Since 1972, measurements have been made at the Baring Head clean air station on the north side of Cook Strait near Wellington.

Atmospheric carbon dioxide levels before the Industrial Revolution were 280 parts per million (PPM).

Dave vividly remembers the first measurements he recorded at Baring Head.

"It was in December 1972, and yes, it was very exciting," says Dave. "We used chart recorders back then and you saw this straight line, which meant that you were measuring an incredibly stable CO2 concentration - and it was around 323 parts per million."

Carbon dioxide concentrations in the atmosphere have since risen to around 410 PPM.

"In my working lifetime it's gone up around 90 parts per million," says Dave. "And that's the whole of the earth's atmosphere. It's a huge hit on the chemical and physical properties of the earth's atmosphere - the only atmosphere that we have."

Keeling's contribution

NIWA technician Gordon Brailsford is an expert in measuring atmospheric gases, and he says that when he began work in this area, CO2 levels were at 347 PPM.

Although sophisticated technology is now used for measuring many types of atmospheric gases, Gordon says that they also still use a method that Dave began using back in the early 1970s.

Keeling bottles were developed by American scientist Charles 'Dave' Keeling, who began the first long term CO2 measurements in Hawaii in 1958.

They are a vacuum flask, which are filled with air by opening the valve "into the teeth of a southerly wind" and sucking in air that, at Baring Head, has blown across the southern ocean from Antarctica.

This clean oceanic air provides background measurements of CO2 concentration that are not influenced by processes on land…

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A replay of a story from May 2018: a citizens' jury on euthanasia.

A replay of a story from May 2018: a citizens' jury on euthanasia.

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When is the Covid-19 vaccine coming? Will it work? William Ray talks to NZ experts charting our path towards immunity.

The Covid-19 vaccine. When is it coming? Will it work? How do we get it to the people who need it most?

William Ray talks to the New Zealand experts who have been tasked with charting our path towards immunity.

Computer generated image of the Covid-19 virus

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Graham Le Gros is an immunology expert. In the days before Covid-19 his work as research director of the Malaghan Institute focused on convincing the human immune system to attack cancer cells.

These days he has another job.

"We could see New Zealand desperately needs to be able to access ," Professor Le Gros says.

"So we put our hands up and said 'why don't we build a consortium of the best people who've got the skills and experience?'"

Professor Le Gros' coalition of the willing is Ohu Kaupare Huaketo - The Aotearoa New Zealand Vaccine Alliance. Back in May 2020, the government gave the Alliance 10 million dollars to research, develop and evaluate Covid-19 vaccines.

That's pocket change compared to massive investments from international pharmaceutical companies and nation states, but Professor Le Gros thinks it's still important for New Zealand to do its part.

"A number of the leading candidates may actually fall over. They may have adverse reactions, or they might be too expensive, or they may not be available in New Zealand," he explains. "As insurance, we are making our own local New Zealand vaccine."

Professor Graham Le Gros is the director of Ohu Kaupare Huaketo - The Aotearoa New Zealand Vaccine Alliance

Testing, testing

Even if we don't end up using a home-made vaccine, Professor Le Gros thinks New Zealand may have an important role in testing vaccines developed overseas.

He says our mostly Covid-free environment gives us an unusual advantage in vaccine testing.

"Having the community completely virus-free is a really powerful way to test the ability of your vaccine to stimulate neutralising antibodies in an unprimed, naive population. It's gold"

Put simply, if you give someone a vaccine in New Zealand and that person develops Covid-19 antibodies, you can be confident those antibodies are there because of the vaccine - not because the person had been exposed to the actual virus.

Professor James Ussher from Otago University works alongside Graham Le Gros at the Vaccine Alliance…

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Lawn owner William Ray looks at the ecological benefits of not mowing and letting your grass grow longer.

We're heading towards summer, and the warmer weather that goes hand-in-hand with fortnightly lawn mowing for lots of New Zealanders.

But a number of ecologists are encouraging Kiwis to cut down on cutting the grass.

William Ray investigates how a 'no-mow' movement might be a win for people, plants, animals - and the climate.

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Associate Professor Bruce Burns thinks a lot about lawns. He's an ecologist at the University of Auckland, specialising in human modified environments.

His interest in lawns was first piqued on a holiday to Europe.

"If you go into those old cities the urban form is very condensed ... there's very little space between houses," says Bruce.

"It got me wondering: why do we have cities in New Zealand which are more spread out? I realised part of the answer was lawns."

Olivia Rooke-Devoy is a PhD student at Auckland University who's been researching lawns alongside Bruce Burns.

She said lawns are a relatively modern invention. They go back to 17th century England and France, where aristocrats had lawns cut by hand using scissors or scythes (the lawnmower wasn't invented until the 1820s).

" was a sign that you had enough money to own useless land," Olivia explains. " was a really exclusive endeavour which only opened up to the suburban class in the early 20th century."

Of course, today's lawns aren't just useless land; they're valued for sport and recreation.

But a lot of lawn is still just there for the sake of it, and some ecologists are encouraging people to think more critically about the environmental and financial costs of lawns.

The cost of lawns

Olivia surveyed a thousand Auckland households on lawnmowing and uncovered some truly astonishing numbers.

Her study found Aucklanders spend $131-million on lawn upkeep every year. And Bruce says local councils spend millions more on the upkeep of public parks, berms and walkways.

It's a big number, but Bruce points out that lawns account for 15 to 20 percent of most urban areas in New Zealand. In Auckland alone, that's 150 to 200 square kilometres.

Trimming all that lawn with petrol-powered mowers creates a lot of carbon. One study in Australia found that lawn mowing accounted for five percent of carbon dioxide emissions on a single summer weekend.

But even if you're using an electric mower, you're still contributing to air pollution…

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Emily Parker and her team at Victoria University of Wellington are identifying the genes that allow fungi to create natural medicinal compounds.

Emily Parker and her team at Victoria University of Wellington are identifying the genes that allow fungi to create natural medicinal compounds.

The idea is to create a genetic recipe book for possible drugs.

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When chemical biologist Emily Parker looks at fungi, she sees a treasure chest of potential medicines.

The Ferrier Research Institute professor has a Marsden grant from the Royal Society Te Apārangi to investigate how subtle genetic differences create diverse and useful chemical compounds in fungi. The results, say Emily, will help tailor-make compounds with medicinal uses.

Emily says that natural chemicals are a leading source of new pharmaceuticals, and she gives penicillin as an example of a compound produced by a fungus that has strong antibiotic properties.

Emily and her team are particularly interested in a group of bioactive compounds produced by fungi known as indole terpenes.

These compounds have been shown to have anti-viral, anti-bacterial and anti-cancer properties, as well as acting as a natural insecticide.

PhD student Rose McLellan works in the Synthetic and Chemical Biology Laboratory at Victoria University of Wellington.

She says that her research project involves creating "some circular pieces of DNA. What I do is transform them into fungi or mould, trying to understand how they make certain compounds so that we can produce them on a larger scale."

The idea, Rose says, is to identify potentially useful compounds and also produce them on a larger scale.

Rudy Bundela's PhD project in the same lab is seeking to understand how "these fungi make these wonderfully complex secondary metabolites."

Secondary metabolites are a by-product that aren't needed by the fungi for its basic survival, but which nonetheless have useful features that could be harnessed by humans.

Emily says that once we understand what individual genes produce, they can be treated as basic ingredients and recombined to make new useful compounds.

Listen to the podcast to hear Emily, Rose and Rudy talk about their research.

More on drug discovery from the Our Changing World archive

Ferrier Research Institute chemist Peter Tyler won the 2017 MacDiarmid Medal for designing and synthesising many potential new drugs to treat diseases such as cancer.

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Unlocking the genetic secrets of natural compounds and the evolution of tieke calls.

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An ecologist and a mathematician discover that teaching a computer to recognise bird calls from acoustic recorders is an interesting challenge.

Training a computer to recognise bird calls turns out to be a thorny mathematical challenge.

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Imagine you are in a forest in New Zealand. It's night. A light wind is rustling through the canopy, and it is raining. Off to the right you can hear the shrill hunting trill of a ruru.

In the distance a pair of North Island brown kiwi are duetting - the higher whistle of the male is answered by the low growl of the female.

You are using sound to identify which birds are calling and you can easily make out the direction the call is coming from. Without you even noticing your brain subtracts the white noise of the wind and rain so you concentrate on the important cues.

Now imagine you are back in your office, you have an acoustic recording of the same night forest and you want to analyse it to find out what species are present and how any there were. How can you do it without having to listen to the entire recording?

Because it turns out that there isn't a computer programme that can do what we humans can do.

And the avian equivalent of the Shazam app that lets you identify any song from just a few seconds of audio doesn't exist. Yet.

But it's something that Massey University ecologist Isabel Castro and Victoria University of Wellington mathematician Stephen Marsland would like to create.

Isabel and Stephen are now the first to admit that if automated birdsong analysis was easy someone would have already done it, and after more than six years of work they are only just making progress.

Stephen says that computer recognition of sound uses pictures. The pictures are visual representations of the bird's calls, spectrograms or sonograms which show time on the horizontal axis and frequency on the vertical axis.

What Stephen and a group of students have been doing is finding mathematical ways of describing the shape of a bird call that a computer can use as its 'search image'.

"But what we've discovered is how hard the real world is," says Stephen. The bush is a very noisy place and a faint bird call in the distance is easily obscured by an amorphous wide frequency band of wind and rain.

The AviaNZ project is developing birdsong analysis software. To date Stephen has worked on kiwi, ruru, kakapo and bittern.

AviaNZ is an open source project with a website where people are encouraged to add filters for new New Zealand species that other researchers can then use…

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An ecologist and a mathematician are collaborating on open source software called AviaNZ that will allow a computer to identify bird calls.

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