Lessons from the Great Dying

We know the story: carbon dioxide released to the atmosphere from coal, oil and gas deposits leads to accelerating global warming, putting stress on species and ecosystems around the world.

Except this is not now, but about 252 million years ago, at the end of the Permian Period and the beginning of the Triassic. Beginning with a massive burst of volcanic activity over a large area of what is now north-central Siberia, the warming was turbocharged by the release of carbon dioxide from dead and dying plants, soils and fossil carbon deposits.

During that 60,000 year period nine in every ten species were extinguished, a near-death experience for the planet’s biodiversity from which it took millions of years to recover.

Cutting-edge technology is enabling science to add detail to what happened back then. A current China-US-UK study of fossil deposits in southern China – a shallow sea in Permian times – has cast new light on the world’s biggest extinction event.

In a recent paper in the US journal Current Biology, the research team concluded that the number of species lost was not as important as losing the functions that keep ecosystems going. This involved a relatively small number of key species.

The team’s research suggests that most of that huge number of Permian species extinctions made no difference to functioning ecosystems. But the end of a crucial few species, the last ones serving a key function in an ecosystem, created tipping points leading to that whole ecosystem’s inevitable collapse along with all its remaining species.

Lesson number one for policymakers: Put conservation efforts into ecosystem health, including habitat conservation, ahead of individual species. We need to think in terms of organisms that keep things ticking over, like pollinating insects and soil communities.

There are a few other things worth keeping in mind about the Permian-Triassic extinction, or “the Great Dying”. It spanned 60,000 years – about the length of time humans have lived in Australia and about a quarter of the entire span of human existence.

Modern climate change dates from early industrialisation 250 years ago. It has seen carbon dioxide levels rise 1.5 times and the mean global temperature climb by 1.2C. The Permian-Triassic mass extinction, which saw the atmospheric CO2 level rise and fall sixfold and the global mean temperature climb by 8C before falling again, took place over 60,000 years.

While we are still discovering details of how the Permian-Triassic mass extinction event played out, it’s safe to say that today’s rate of change in both mean temperature and atmospheric carbon is many times – in the case of the latter at least 40 times – greater than back in end-Permian times. Considering that CO2 molecules released today will on average stay in the atmosphere for 1000 years, global fossil-fuel emissions remain completely out of hand.

Lesson number two for policymakers: Stop boasting about climate leadership and a role for coal or gas in our future – both unfounded. Do everything humanly possible to eliminate fossil fuels from our economy and our lives, and start now. If only yesterday was an option.

All top decision makers should be across current science, but where does that leave others, especially those who unlike me have most of their lives ahead of them? Scary comparisons with ancient extinction events do nothing for the state of mind of ordinary folk with enough worries keeping a roof over the head and food on the table.

We inevitably have our own pessimistic or optimistic thoughts about the future, but preaching doom or sliding into optimistic complacency are both equally useless. Nothing in the future is written in stone, and some genuine revolutions are ahead in the technology, rollout and economy of new energy, energy storage and transport options.

Blind optimism is dangerous and destructive, but informed optimism is empowering. We need to bear in mind that the world won’t recover if people don’t act to help it out. The actions needed involve a lot of effort over many years, a lot of persuading and cajoling and going out on limbs. And responsible leadership. But we can still win this.

ON FRIDAY (21 April) and through next weekend, people concerned that we need a stronger response to the climate crisis are invited to gather on Hobart’s Parliament Lawns to explore how the Tasmanian community and their leaders can together contribute to the global effort to restore our planet to health.

“Uniting to Survive”, from 1 pm Friday and 10 am Saturday and Sunday, is being planned as a family-friendly event aiming to bring people together. It is being organised by a wide array of community and conservation groups. Full disclosure: I am a speaker at this event.

This entry was posted in Uncategorized. Bookmark the permalink.