Perched atop a cliff in Tasmania’s remote north-west corner, the 80-metre-tall tower and small hut look rather unassuming.
But it was this site that helped deliver the monumental proof that humans are changing the Earth’s climate.
The Kennack/Cape Grimm Air Testing Station, run by a small team of scientists, also provided evidence that change can happen when the world comes together.
And as it celebrates its 50th birthday, this place that has been making history for half a century may be more important than ever.
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One world, one atmosphere
Former CSIRO scientist Graham Pearman was one of the few people originally involved in setting up what would become one of the world’s most important observatories for tracking human-induced changes in Earth’s atmosphere.
The early days were modest.
The equipment was stored in an old NASA caravan that was once used during the Apollo missions.
Graham Pearman helped establish the Cape Grim Baseline Air Pollution Station 50 years ago.
The story of how Dr. Pearman got there began far away, atop a rugged cliff overlooking the Southern Ocean.
In the early 1970s, he was measuring carbon dioxide (CO2) on a wheat crop for another project when he noticed something strange.
The Cape Grim Atmospheric Monitoring Station was originally built from an old NASA caravan used in the Apollo missions. (Provided by: CSIRO)
The levels were about the same as those recorded on the other side of the world by scientist Charles David Keeling, who was tracking Hawaii’s carbon dioxide levels.
It didn’t seem to make sense.
“We couldn’t understand why two very different hemispheres – one mainly covered by ocean and one mainly covered by land, one hemisphere with lots of people and one with not so many people – could have such similar concentrations,” he said.
But the following year, through an aircraft observation program, he realized that his measurements were correct, confirming the suspicions shared by Dr. Keeling.
CO2 levels are rising around the world, and fossil fuels are the culprit.
“I never believed that Mother Nature was so fragile that humans could actually interfere with it.” he said.
Over the next three years, plans are in place to establish a permanent Australian Background Observatory, jointly managed by the Australian Bureau of Meteorology and CSIRO, currently known as Kennaoak/Cape Grimm.
Technology has changed a lot since the early days of this site. (Provided by: CSIRO)
Bottling the cleanest air on earth
Twenty-four hours a day, air is drawn in from the surrounding coastline through an inlet 80 meters above the tower and analyzed in real time.
However, what the station sees is far from local. That’s why this site is one of only three “premier” world broadcasters.
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Strong westerly winds from the Southern Ocean, known as the “Roaring Forties,” placed the base directly in the path of air that had traveled thousands of kilometers without touching land.
This makes it one of the cleanest places on earth.
And for scientists, that’s gold.
Air is drawn in through the inlet from the surrounding coastline 24 hours a day and analyzed in real time. (ABC News: Jano Gibson)
CSIRO scientist Melita Keywood, who leads the aerosols and reactive gases program at Cape Grim, said the measurements taken there reflected the true background atmosphere of the entire planet, unaffected by local pollution.
“When you see the clean atmospheric changes that we’re measuring at Cape Grim, you know something has happened on a global scale. So that’s what’s really important about Cape Grim,” Dr. Keywood said.
“A lot of the things we’re interested in also impact people, human health, and ecosystem health.”
The Cape Grim site is part of a global network of atmospheric monitoring outposts and is the only one of its kind in Australia. (Provided by: CSIRO)
Each season, air samples are also bottled and stored in the world’s oldest aviation archive in Melbourne. This allows researchers to go back in time and test the air for gases that have not been studied in the past.
Recently, a donated scuba tank was also added to the collection, and its records go back even further.
How has the world changed in 50 years?
One of the clearest stories in the data on this site is the rising concentration of the greenhouse gas CO2.
As Dr. Keeling’s early measurements in Hawaii suggested, CO2, the main cause of human-induced warming, is steadily increasing.
In 1976 it was around 330 ppm, and today it is over 420.
This increase in itself is significant.
But when you compare that with records from ice cores that can go back hundreds of thousands of years, the true scale becomes clear.
“This is a huge change in the composition of the atmosphere that occurred over a period of less than 100 years, and changes of such magnitude have not been observed anywhere in the past million years,” Dr. Pearman said.
The story of the ozone hole
As Cape Grim’s greenhouse gas data continues to rise, another data set is showing a surprising turnaround.
Immediately after opening, the station began measuring chlorofluorocarbons (CFCs). This gas would later be associated with the Antarctic ozone hole.
It rapidly increased in the late 70’s and 80’s due to aerosol cans, refrigeration, and widespread use in manufacturing.
But levels began to decline in the 1990s after the Montreal Protocol, a global agreement to phase out ozone-depleting substances, was enacted.
British scientists discovered a “hole” in the sky above Antarctica in 1985, but long-term records from Cape Grim helped confirm the cause and track its subsequent recovery.
CSIRO scientist Paul Cramer said: He, who heads the Greenhouse Gas and Ozone Depleting Substances Program, said the data also helped detect illegal fluorocarbon emissions from China in the 2010s.
“We realized that CFC-11 was not declining as fast as we thought it would,” Dr. Krumel said.
“And because we are part of a global network, it turns out that through that we ended up with illegal emissions and production in eastern China.”
Paul Cramer at CSIRO’s Kennack/Cape Grim Aviation Archives in Aspendale, Melbourne. (ABC News: Jordan Young)
This recognition led to international pressure and a crackdown on illegal production.
Restoring the ozone layer is widely considered to be one of the most successful global environmental actions, demonstrating how unified global action can bring about change.
Uncertainty looms over “Cinderella Science”
Lacking the flashy discoveries of hypothesis-based science, research at Cape Grim is sometimes referred to as “Cinderella science.”
But Dr. Krummel said it confirms much of what we know about the atmosphere.
“You can’t really mitigate what you can’t measure,” he said.
Aerial view of Cape Grim Atmospheric Monitoring Station in Tasmania. (Provided by: CSIRO)
The observations also helped corroborate climate models and informed both domestic and international policy.
But Cape Grim’s 50th birthday comes at an uncertain time for science, as the world once again sets global emissions records.
Imminent CSIRO job cuts come at ‘pivotal moment’ for climate action
In Australia, the CSIRO is facing significant job cuts in its research departments, including reports that more than 100 jobs have been lost in its environmental research division, which covers atmospheric science such as Cape Grim.
In an open letter, Australian Meteorological and Oceanographic Society (AMOS) president Sarah Perkins-Kirkpatrick said long-term monitoring relies on continued investment and expertise and it was “essential” to protect that capability.
Professor Perkins Kirkpatrick said: “A decline in scientific capacity risks undermining the datasets that underpin our understanding of environmental change.”
“Ensuring this research can continue is critical to Australia’s contribution to global climate science and our ability to adapt to future changes.”
In the United States, President Donald Trump has already cut major climate change and science agencies, and further cuts are being considered.
The National Oceanic and Atmospheric Administration (NOAA) is already facing significant cuts in the United States, and further cuts are being considered. (Getty Images via AFP)
Proposals have been floated to scale back major climate and science programs, including the original Mauna Loa Observatory in Hawaii.
Dr Keywood said this would be a “significant loss” as each site played an important role in putting together a global picture.
“The Northern Hemisphere stations, especially the Mauna Loa station, are the first to see things changing,” Dr. Keywood said.
“But there will be a short delay before they move into the southern hemisphere and we measure them at Cape Grimm.
“These are all different pieces of information that are very important to put together to understand the big picture, especially if you want to predict what will happen in the future.
“We need to understand all of those different processes.”
