The Sound of Climate Change is an outreach project making climate change tangible through acoustic based experiments that connect us to the invisible world of infrared light, atmospheric gases, green technology and the creatures we have been entrusted to care for.

How we measure carbon dioxide in the air?

How is climate change connected to living creatures?

We want to first acknowledge the traditional owners on which this work was undertaken the Whadjuk people of the Noongar nation as Traditional Owners and Custodians of the area Boorloo (Perth) as well as the First Nations people of Mauna Loa (Hawaii), we give our respects to their ancestors and Elders and Senior Knowledge Holders, past, present and those following in their footsteps.

We also want to acknowledge the generous funding of

the Acoustical Society of Australia through the Richard Booker Education Grant,
Forrest Research Foundation,
Curtin University and
Danjoo Koorliny.

The project was developed and supported by

Curtin University: Curtin Carbon Group/Physics and Astronomy - Dr. Jacob Martin, Ryan van der Berg, Finn Manning, Carl Lares; Curtin Hub for Immersive Visualisation and eResearch - Dr Andrea Rassell; Centre for Marine Science and Technology (CMST) (Prof. Christine Erbe, Dr Chong Wei, Prof. Robert McCauley, Dr Iain Parnum); John Curtin Gallery - James Dudding, Bjoern Rainer-Adamson; Curtin Outreach - Andrew Hannah; Curtin Place Activation - Greg Dunn; School of Earth and Planetary Sciences - Renae Sayers, Mia Walker,
Danjoo Koorliny (Dr Noel Nannup OAM, Bruce Davies),
Forrest Research Foundation (Louise Renwick, James Arvanitakis) and Minderoo Foundation (Lara Smith).

Project updates

WA Acoustical Society Meeting | 21 Oct 2024

Presentation - How Acoustics is Used to Monitor Climate Change?

Demonstrated photoacoustics with an LED torch and portable CO2 monitors that use photoacoustics detection.

How Acoustics is used to monitor climate change.pdf

Richard Booker Education Grant | 12 Nov 2024

The Australian Acoustical Society awarded the "Sound of Climate Change" the Richard Booker Education Grant to explore the photoacoustic detection of carbon dioxide and the history of climate change measurements.

https://www.acoustics.org.au/activities/education-grant/

Casuarina Prison Programme | 29/30 Jan 2025

Presentation - Carbon Nanoverse and the Energy Transitions

Demonstrated photoacoustics with an LED torch and carbon inside green technology like lithium-ion batteries.

See the video to the left showing the activities undertaken.

Tiktok video | 30 March 2025

Ryan van der Berg's Tik Tok video explaining climate change with a infrared camera demonstrations developed as part of this project

Cosmos on Campus | 2 & 3 May 2025

Exhibition at the John Curtin Gallery showcasing the Climate Chair & infrasound research at Curtin University with the Planet Shaker Platform.

We had 3,200 people through the exhibition over two night. Feedback from the exhibition was that kids was that they are very keen to do something to combate climate breakdown. Many adults were very moved particularly when it got to 2030 when CO2 levels need to peak.

Thanks to Ryan van den Berg for running the exhibition alongside Andrea Rassell.

See photos from the event as well as infographics prepared for the Climate Chair and Planet Shaker platform below.

Bioacoustics laboratory | 15 May 2025

Slides for laboratory.pdf

Presentation - Feeling the climate and blue whales songs.

The Climate Chair was modified with a new class-D amplifier to be highly portable and to used during a undergraduate laboratory on bioacoustics.

Danjoo Koorliny Djilba Social Impact Summit | 5/6 Aug 2025

Exhibition - Kooranyi Nyinning: Mammung's Lost Song

Thanks to Danjoo Koorliny Elder Dr Noel Nannup for naming and developing the written description, and Bruce Davies for developing the graphics for this exhibitions and Narissa De Bruin for facilitiating the exhibition. Over 90 experience the chair and a small platform that was developed to stand on and feel the vibrations through the feet.

National Science Week | 16 Aug 2025

Exhibition Carbon Vibrations - Infrasound at the Forrest Hall National Science Week event

Physics@Adventure World | 25 Sept 2025

Demo - How Acoustics is Used to Monitor Climate Change?

Demonstrated photoacoustics with an LED torch and portable CO2 monitors that use photoacoustics detection.

Pecha Kucha Event with Minderoo | 23 Oct 2025

The Sound of Climate Change_Pecha_Kucha.pdf

Presentation - The Sound of Climate Change

Demonstrated Climate Chair and small platform with carbon dioxide signal.

See the presentation to the left.

Acoustics 2025 Conference | 13 Nov 2025

Workshop - The Sound of Climate Change (and other infrasound)

Abstract: Come and hear how sound has been used to measure climate change for over 60 years. The 20 Hz signal generated from the Keeling Curve recordings has been turned back into a sound that can be heard and felt using a data sonification led by Dr Andrea Rassell. The seasonal variation is extrapolated back to 1900 when the carbon dioxide level is stable and pushed forward to 2100 according to the RCP2.6 trajectory to provide people with a hopefull path towards the future. This cannot be heard but felt using a special infrasound equipment developed at Curtin University or through the commercially available Woojer belt. Here we demonstrate how low frequency sounds like those from blue whales, asteroids and rockets can be experienced!

A place activation was also set up before the dinner at the Western Australian Aquarium. Thanks to Finn Manning for running the photoacoustic demonstrations. Approximately 20 people visited the workshop and 20-40 people experienced the space activation before the dinner.

Navigating Climate Scepticism | 20 Nov 2025

Online course developed with AXA Climate and La Prod Jolie

During the Sound of Climate Change project we were approached by AXA Climate to support a documentary on Climate Scepticism. Dr Andrea Rassell filmed Dr Jacob Martin for integration into the course.

You can visit this link to the see the course video online.

Fires of Wisdom - Documentary Screening | 5 Dec 2025

Moondanark Kaartdijin / The Carers of Everything | The Practice of Mosaic Burning and Biochar

A documentary which explores the wisdom of traditional mosaic burning and its vital role in healing Country and climate. Dr Jacob Martin consulted on the project and was involved in the cultural burn taking audio recordings of the infrasound from the fire.

At the screening the Whale Chair and infrasound platform was demonstrated as well as recordings of the fire with approximately 20 people participating.

How we measure carbon dioxide in the air?

Charles David Keeling

The ground-breaking measurements of atmospheric carbon dioxide (CO2), started by Charles David Keeling in 1958.

Mauna Loa's fresh air

Keeling chose the island of Mauna Loa as fresh air from the trade winds blew over the island providing a representative sample far from human sources of carbon dioxide.

Model 70 Infrared analyser

Keeling installed an Applied Physics Corporation dual detector infrared analyzer from 1958 that operated until 2006.

What is infrared light?

Infrared light is invsible light with lower energy than red light. Radiant heat from a heater is infrared light.

This was discovered by Herschel in 1800 a recreation of the experiment can be found in the video on the left.

https://science.nasa.gov/mission/webb/science-overview/science-explainers/infrared-astronomy/

Photoacoustic effect

Alexander Bell (the inventor of the telephone) discovered the photoacoustic effect where flashing sunlight on some soot collected from a candle made a sound.

Si photodiode that demonstrates the rapid switching of the torch in the dim setting. This control of the power is called pulse width modulation.

Experiment 1 - LED torch photoacoustic demo

Many low cost LED torches have a dimming function that turns off and on the LED too quickly to be seen but at audible frequencies.

By shining an LED torch at a black object you can hear the photoacoustic effect audibly. A 500 - 1000 Lumen torch is needed to be able to hear the noise and more expensive torches will use current controlled power supplies so will not work.

A black beanie is a good option or some black ink printed on a paper. To create the loudest effect just like Bell collect some soot from a candle but onto a piece of aluminium foil and shine the torch onto this for an effect you can hear from less than a metre away.

Care must be taken to not shine the torch into the eyes and it is suggested to setup the demo in a clamp mount to students to listen to without being able to shine it into their eyes. See more details here on the safety of white LED and the issue of blue light exposure.

Recommended extensions for advanced students in physics include using the Phyphox iphone/android application to collect a spectrum and be able to see the many harmonics that are associated with the square wave audio signal being generated.

Similar experiments are listed below.

M. Euler, K. Niemann, and A Müller, “Hearing light,” Phys. Teach. 38, 356 (Sept. 2000).

Peters, Rachel E., and Han Jung Park. "Photoacoustic Demonstration: Making Music with Light." Journal of Chemical Education 98.4 (2021): 1342-1346.

https://physicsopenlab.org/2020/04/06/a-photoacoustic-demonstration-experiment/

Listening to infrared light

This was used to demonstrate the the sun produces near infrared light by splitting the light through a prism and listening to the invisble rays.

Thermal cameras

Today we can use a thermal camera, which is made up of thousands of tiny thermometers, to see the invisble infrared light or heat that is emitted from ourselves or the earth.

Carbon dioxide absorbs infrared heat

Tyndall in 1882 discovered that infrared light is absorbed by greenhouse gases like carbon dioxide using the photoacoustic effect. Flashing infrared light onto a vial filled with carbon dioxide allowed Tyndall to hear carbon dioxide emitting sound as it heated and cooled. A modern demonstration of this can be found here https://pubs.acs.org/doi/full/10.1021/ed8000446

Model 70 Infrared analyser

In Keeling's instrument a heat lamp was flashed very quickly using a rotating shutter. This flashing heat caused the carbon dioxide to warm and cool creating pulses of sound that were measured using a microphone.

The loudness of the signal could be directly used to measure the concentration.

More information can be read for free at this article https://pubs.acs.org/doi/10.1021/ac1001492

Inside the qingping co2 sensor has a Sensirion photoacoustic sensor on the top left of the circuit board.

Experiment 2 - Sensing CO2 in the classroom

During COVID many low cost carbon dioxide sensors were made as a way to see if the inside air was being well circulated and you were not breathing in other peoples breath.

The outdoor concentration of CO2 should be around 400 ppm. But with people indoors it can quickly rise. Above 1000 ppm you will start to feel sleepy and above 2000 you will become sleepy. From 2,000 to 5,000 ppm you can get headaches and nausea. Reaching 50,000 ppm or 5% of the air is a toxic level for humans but this does not happen in building as they are not air tight.

Some of these carbon dioxide sensors use a low-cost photoacoustic detection at 20 Hz just like Keeling did. There are two main brands Sensiron and Infineon, two microphone companies that produce evaluation kits as well as being integrated into many low cost sensors you can buy for <100 USD. Here are some we have tested.

Sensirion SCD4x comes in a USB type that connects to your phone (40USD) and are found in the qingping CO2 sensors (40 USD) that also connect to your phone and have a screen to nicely show you the reading as well as being battery powered.
Infineon PASCO2Vx which comes in a USB evaluation package called sensor2go that connects to your computer to plot a graph of CO2 on the screen (36USD).

In the graph below taken with the infineon sensor 50+ people were in a closed room during a conference from 9 to 11 am. The air was not circulated from 9-10 am and many people were feeling drowsy. At the break at 10 am I opened the windows and the CO2 levels came down. Then at 10:35 am the doors were closed and the air handling was turned on that keep the CO2 at a good level.

Keeling, Charles D., et al. "Atmospheric carbon dioxide variations at Mauna Loa observatory, Hawaii." Tellus 28.6 (1976): 538-551.

Keeling curve

Keeling was able to make many measurements very day to build up the

Keelings first found a seasonal variation as trees in the northern hemisphere took up more carbon dioxide during the summer. This can be thought of as the earth breathing.

By the 1970s the rising trend in carbon dioxide concentration was clear and indicated it was building up in the atmosphere.

https://gml.noaa.gov/outreach/faq_cat-3.html

Carbon dioxide into the past

To measure ancient carbon dioxide in ice cores scientists first crush or melt a small piece of ice inside a vacuum line to release the tiny bubbles of air that were trapped when the snow fell. The liberated air is then fed into a gas chromatograph which separates the gases and measures the amount of carbon dioxide with very high precision. Early systems in the 1970s converted the carbon dioxide to methane so it could be detected more easily and later systems improved the extraction and calibration steps to reach parts per million accuracy. These methods allow us to read the atmosphere of the past directly from the air trapped in the ice and provide the long record that links the Law Dome data to the modern Keeling curve.

Keeping temperature below 1.5 °C

In 2014 the Intergovernmental Panel on Climate Change (IPCC) began to use representative concentration pathways. The pathway labelled RCP2.6 provides us a chance of keeping temperatures below 1.5 degrees celcius.

This trajectory and the ice core data was integrated with the seasonal variation as part of a student project by Ty Riekart. The curve can be seen below.

Data sonification

In order to turn this data into something that you can listen to the concentration was mapped to the frequency of the sound. Our ears are most sensitive to frequency instead of volume so this most easily translates the data into something you can listen to.

We also developed a version that includes all of the frequencies up to 280 Hz this is brown/white noise and as the concentration increases the filter moves to a higher frequency.

Mauna Loa station to be closed! | 17 July 2025

In 2026 the budget for the Mauna Loa monitoring station for carbon dioxide will cease. This represents a significant challenge to the ability to measure and understand out atmosphere. While there are many other testing stations around the world it is still a loss the longest running measurement of carbon dioxide.

https://gml.noaa.gov/ccgg/about.html

How can you feel carbon dioxide?

Vibro-tactile technology for listening to Keeling's curve

Credit: https://dosits.org/

Infrasound

The 20 cycles per second (20 Hz) signal that Keeling recorded are below the audible frequencies for humans. Humans can hear from 20-20,000 Hz.

While we cannot hear these low frequencies we can feel vibrations down to one cycle per second (1 Hz).

Credit: https://audioxpress.com/article/building-a-haptic-dimension-the-science-behind-the-taction-transporter

Tactile bass

Tactile bass audio equipment has been developed to enable mixing of house music in a studio setting enabling the sound to be felt <100 Hz.

For a great article on tactile bass see this link. https://www.earthquakesound.dk/wp-content/uploads/2021/04/Bass_Shakers_and_Tactile_Sound_Audio-Express.pdf

As part of this project we tested different tactile bass equipment and only found the Buttkicker equipment to provide good bass response at 20 Hz.

Classroom demonstration

An audio amplifier can drive a shaker that is common in many high school class rooms to allow students to feel the orginial signal that Keeling would have measured.

The only other cost effective option for something that is plug and play is the Corsair Headphones with the patented Taction Transporter that can produce vibrations down to a few Hertz.

In the recording below the volume is related to the concentration and the frequency is set to the 20 Hz the frequency that Keeling originally measured CO2 with.

The infographic below and sound cloud link show the waveform where the width is the volume and the frequency for the signal is 20 Hz.

How is climate change connected to living creatures?

Climate change and blue whales

www.mammungthefilm.com/about

Losing MAMMUNG to the sea

"MAMMUNG is the Noongar name for the whale.

Around 10,000 years ago Western Australia experienced rapid sea-level rise. At that time, the indigenous Noongar people adapted to the loss of almost 30% of their land as the population moved inland ahead of a 'slow moving tsunami'. MAMMUNG the film explores the living memory that Noongar people hold of this event. The film follows Dr Noel Nannup in recalling the significance of places which are now below the sea and explaining the process of change that indigenous people endured through the narrative dreaming story of MAMMUNG the whale.

Indigenous cultures in Australia are one of the very few who have a living memory of a period climatic change that rivals what we are seeing today. MAMMUNG the film challenges us all to ask: can we learn to understand and value this rich body of knowledge as we too adapt to a changing climate? and what awaits us if we don't?"

www.mammungthefilm.com/about

Image credit: https://www.bas.ac.uk/data/our-data/publication/ice-cores-and-climate-change/ Osman, M.B., Tierney, J.E., Zhu, J. et al. Globally resolved surface temperatures since the Last Glacial Maximum. Nature 599, 239–244 (2021). https://doi.org/10.1038/s41586-021-03984-4 Shakun, J., Clark, P., He, F. et al. Global warming preceded by increasing carbon dioxide concentrations during the last deglaciation. Nature 484, 49–54 (2012). https://doi.org/10.1038/nature10915

Stability means peace

In the Mammung documentary Dr Noel Nannup speaks about a stable climate meaning peace for the people.

Over the last 10,000 years we entered into a uniquely stable period of the climate where the concentration has not changed by more than 20 ppm and the temperature by <1.0 degrees.

A stable climate allowed modern agriculture to thrive as crops relaibly grew in particular regions.

The great flood

Twenty to ten thousand years ago changes in the earths orbit around the sun led to a warming of the planet and a melting of glacials. The sea level rise was over 100 metres. Many ancient stories discuss the global flood that ensued and the significant impact it had on coastal people that saw their lands swallowed by the ocean.

The Whadjuk people of the Noongar nation of Boorloo (Perth, Western Australia) have a story of loss from this time.

Land bridge connecting Noongar to Wadjemup

Guidebook to the Geology of Rottnest Island by Phillip E. Playford

Perth Canyon the size of the Grand Canyon

Google Earth, Data: SIO, NOAA, U.S. Navy, NGA, GEBCO, Landsat/Copernicus, LDEO-Columbia, NOAA

WARNING: VIDEO SHOWS GRAPHIC SCENES OF WHALES BEING SLAUGHTEREDCredit: British Pathe, Whaling with new harpoon gun in the Indian Ocean (1937)

Industrial whaling

Starting in the 1900 oil powered boats and new harpoon technology with exploding heads enabled industrial whaling on a scale that had never been possible before.

https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1748-7692.2004.tb01190.x

Hunted to near extinction

Starting in 1934 the whaling industry began to be regulated under the league of nations as blue whales had almost completely disappeared from the ocean.

These regulations did not stop the almost complete extinction of blue whale populations by the 1950s.

Listening to the humpback whale

In 1970 bioacoustics scientist Roger Payne working with the Navy Engineer Frank Watlington released the Songs of the Humpback Whale [1]. In 2021 [2] Payne told the science magazine Nautilus;

“My idea was, if you can move people emotionally, you can also get them to act. To see if I was right, I started playing humpback whale sounds to friends and other small audiences, and soon it became very clear that these sounds moved people deeply. In fact, some friends wept when they heard them—they’re that powerful.”

[1] https://www.theguardian.com/environment/2023/jun/16/roger-payne-60-years-discovery-of-whale-song-their-haunting-sounds-reveal-new-secrets

[2] https://nautil.us/the-man-who-seduced-the-world-with-whale-songs-2-238297/

Banning whaling

These recordings inspired the growing Save the Whales movement that led to the 1972 United Nations Conference on the Human Environment ten-year global moratorium on commercial whaling.

Return of the blue whales

Since whaling was outlawed there has been a recovering in the numbers enabling the numbers to begin to recover and feeding areas like the Perth Canyon to begin to have blue whales return.

https://www.abc.net.au/news/2014-06-04/curtin-university-investigates-possible-mh370-signal/5500198

Listening blue whales songs

Scientists at Curtin's Centre for Marine Science and Technology have been listening to this recovery for the last two decades using underwater microphones. Here is a collection of recordings

Similar recordings from the Australian Antartic Program has shown similar recovery. Here is a collection of recordings and a video below.

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