Cape Grim climate milestone underscores need for urgent action


Tasmania’s Cape Grim atmospheric monitoring site has passed the symbolic but significant milestone of 400 parts per million (ppm) of carbon in the atmosphere for the first time, again highlighting the growing burden burning fossil fuels is putting on the planet. This is not the first time the milestone has been passed globally, with sites in the Northern Hemisphere registering 400ppm at various times since 2012. What is different, is that Cape Grim’s very clean air represents a stable baseline with less seasonal variation than other sites, and now that it has passed this milestone it will not dip below it again. We’re already seeing the many brutal impacts of rapidly increasing concentrations of CO2 in the atmosphere, including the Tasmanian wildfires, unprecedented bleaching of the Great Barrier Reef, and the relentless smashing of temperature records. Unfortunately, under the Turnbull Coalition government CSIRO cuts – including at Cape Grim – are continuing, and they are leaving us flying blind on climate change.


Key Points

  • Greenhouse gas levels have hit a symbolic, but record peak. Until around 1850, global CO2 levels were running at roughly 280 parts per million (ppm). 350ppm is a level considered “safe” from the worst impacts of climate change, but that was eclipsed in 1988. As Cape Grim, Tasmania, has the “world’s cleanest air” and a strong, stable baseline for atmospheric measurements, its passing of the 400ppm milestone is significant. It has come much earlier than anyone expected, as record fast increases are being logged at other stations, and as now that is is past the 400ppm point it is unlikely to drop below it again on a meaningful timescale or unless “we get very good at mitigation”.
  • We have entered uncharted territory on climate change, and the largest single cause is the burning of fossil fuels. The ink on the Paris agreement is well and truly dry now, and the hard work of rapidly phasing out fossil fuels for clean, sustainable alternatives must get underway. The increase of atmospheric concentrations of CO2 measured at Cape Grim are a sign that more must urgently be done to stop burning fossil fuels, and for Australia that means a strong move away from bothy burning and selling coal.
  • We have changed the climate for the worse, but we can still change it for the better. Milestones such as Cape Grim’s 400ppm are reminders that while we are rapidly changing the global climate through our actions, it is within our power to remedy it. Better still, we know that the solutions, such as switching to clean, renewable energy sources, yield huge economic and health benefits.



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Key Quotes

  • “During the last 4 days, the CO2 [carbon dioxide] levels at Cape Grim have risen above 400 parts per million (ppm) […] I don’t believe we’ll go below 400 for many years—if at all.– CSIRO Atmospheric scientist Paul Krummel
  • “It’s probably one of the last places on Earth to actually reach this milestone, and it just highlights the ever-increasing levels of CO2 in the atmosphere. It’s another milestone that we’ve reached where it’s indicating that the health of the planet is probably in trouble.” – CSIRO Atmospheric scientist Paul Krummel
  • “Once it’s over [400 ppm], it won’t go back.”– Retired CSIRO fellow Paul Fraser
  • “This is a global emergency and alarm bells should be ringing for Malcolm Turnbull and Bill Shorten who are championing new coal mines and fossil fuel subsidies. Australians already understand the need to rapidly transition to clean energy but the old parties are stuck in the past, continuing to approve new coal mines to please their big mining donors. The science out of Cape Grim is clear – our atmosphere cannot take any new coal mines. We must actively reduce our carbon pollution, not pump out more by digging up more coal or fracking more gas.” – Australian Greens climate change spokesperson, Senator Larissa Waters

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