Chris Packham's BBC Series Warning of "Mass Extinction" by CO2 is Propaganda, Not Science

Last year, Chris Packham hosted a five-part series on the BBC called Earth, which compared a mass extinction event 252 million years ago to the small rise in atmospheric carbon dioxide seen in the last 150 years. He said he hoped the “terror factor” generated by his programme would “spur us to do something about the environment crisis”. But as we shall see, the only terror factor is having to sit through an hour-long film consisting of cherry-picked science data and unproven assertions in the hope of persuading us that the increase in global temperatures in the last 150 years or so is comparable to the rise in temperatures over a considerable swath of geological time. Great play was made of a 12°C rise in average global temperatures 252 million years ago as CO₂levels started to rise, although Packham fails to report that CO₂ levels were already at least four times higher back then than in modern times. The ‘science’ that Packham cloaks himself with on every occasion is hardly served by terrorising the viewer with what is little more than a highly personal political message.

Think of all that suffering and wastage, he says about the fourth great mass extinction. I don’t think we want a comparable extinction to the one that happened 252 million years ago on our conscience, he adds. Of course, Packham is not the first person to politicise the end-Permian extinction when most plant and animal life disappeared to be replaced eventually with what became known as the age of the dinosaurs. As we can see from the graph below, even though that extinction event coincided with an uptick in CO₂ levels, the general trend over a 600-million-year period was downwards ending in the near denudation currently experienced today. But scientists note that the rise started some time before the extinction event, with most of the Permian characterised by very low levels of CO_2.

It is obvious why the three other great extinctions are of little interest to modern day climate alarmists. The Ordovician extinction 445 million years ago occurred when CO₂levels were 12 times higher than today, the Devonian wipe-out happen 372 millions ago when CO₂ levels were falling, while the later Triassic/Jurassic event 201 million years ago occurred at a time of stable CO₂. Hard to see a pattern there suggesting rising CO₂levels equals a mass extinction event. The disappearance of the dinosaurs 66 million years ago is generally attributed to the impact of a giant meteorite, while the current sixth mass extinction exists only inside the head of the Swedish doom goblin, and need not detain us at this point.

Since Packham was essentially making a BBC political film promoting Net Zero, he inevitably started with the fixed view that all our current environmental problems are the fault of CO₂. An intense period of volcanic eruptions that led to huge coal deposits catching fire increased CO₂ levels and almost instantly sent temperatures soaring at the end of the Permian period. About 20 million years of rain subsequently followed, he observed, taking some of the CO₂ out of the atmosphere and order it seems was restored. Certainly, CO₂ resumed a small descent but levels remained almost as high, or for some periods higher, as those at the end of the Permian period for another 120 million years. Packham does not provide an explanation of what happened to the average global temperature at this time.

The graph above shows why he avoided the subject. Temperatures did rise at the end of the Permian period after a long decline, but only as far as previous highs recorded 200 million years earlier. They then stayed at those levels for most of the next 200 million years, throughout the age of the dinosaurs. Helped by the increased levels of CO₂, this is considered one of the most verdant periods in Earth’s history.

Is it likely that volcanic eruptions triggered the substantial rise in temperature around 252 million years ago, as Packham claims? In a paper published in 2022, a group of European scientists said their data showed seawater temperature began to rise at least 300,000 years before the main volcanic eruptions. “Gradual warming by approximately 12°C was probably responsible for initial environmental degradation that eventually culminated in the global and Permian extinction,” they wrote. The scientists reviewed much of the published evidence and concluded “a temporal link between volcanic activity, environmental changes and biological impacts remains controversial”.

Carbon dioxide, of course, is the main cause of global warming in Packham’s world. Promoting his film to like-minded activists at the Guardian, he said it was the “urgency that makes me despair”. As we can see, this “despair” is the result of comparing events hundreds of millions of years ago with a small temperature rise in the past 150 years or so of around 1°C – and this after a short-term period of global cooling. You can of course argue about all this, but it is a bit rich to claim the science of recent global warming is ‘settled’ and refuse to debate anyone who disagrees with you.

From such a shaky base, Packham claims we’re all becoming far too complacent about pumping CO₂ into the atmosphere. “It’s an experiment we have been running for over 100 years,” he told the Guardian. “The more the CO₂, the more the heat is locked in and the hotter our Earth becomes.” But if Packham really believes that, how does he explain those geological periods when temperatures fall as CO₂ levels rise? And if a rise in temperatures and mass extinction is inevitable when CO₂ rises, how does that work in the current period when CO₂ levels are as low as they’ve ever been?

Could it be that the end-Permian extinction was actually caused by CO₂ starvation? During the Permian, it was the first time in Earth’s history that CO₂ concentrations fell below 1,000 parts per million, perhaps as dangerously low as 200 ppm at some points. This may well have started to stress plant life since 1,000 ppm is a concentration that supports maximum photosynthesis productivity. This is the view of Jim Steele, Director Emeritus of San Francisco State University’s Sierra Nevada Field Campus. In a recent paper, he noted that many researchers have pointed to competition between different plant species for declining CO₂during the Permian period. This was said to result in “severely reduced photosynthesis, the collapse of primary productivity and a significant malfunction of the global food webs”.

The truth is that the scientific jury is still out and the ‘science’, as with most climate science, is unsettled. Perhaps inadvertently, Packham has simply drawn attention to all the observational evidence that suggests CO₂, the gas of life, ‘saturates’ at around 300-400 ppm, and its warming effect is greatly diminished beyond that concentration. But “fear is motivating” he claims, and in the BBC he seems to have a compliant megaphone for whatever green propaganda he cares to promote.

Chris Morrison is the Daily Sceptic’s Environment Editor.