James Hansen's Faustian Bargain And The Deliberate Conflation Of Weather With Climate

Hansen, along with co-authors, has released a new study just ahead of COP 28 which basically claims ‘man-made climate change is much worse than we thought’. He derives a new, far higher estimate of climate sensitivity to doubling of atmospheric CO2 of 4.8C by re-examining paleoclimate data and furthermore claims that a reduction in man-made aerosol emissions - notably the recent near elimination of sulphates from ship diesel fuel - is driving a very recent ‘spurt’ in global warming which will mean that we pass the 1.5C ‘OMG we’re all going to DIE!’ threshold much sooner than previously expected. Nic Lewis and even Michael Mann have criticised his latest doom laden ‘scientific’ offering, but have re-iterated their respect for the great pioneering scientist. I’ll just stick to criticism here. In typical form, this is the Guardian headline:

Global heating is accelerating faster than is currently understood and will result in a key temperature threshold being breached as soon as this decade, according to research led by James Hansen, the US scientist who first alerted the world to the greenhouse effect.

The Earth’s climate is more sensitive to human-caused changes than scientists have realized until now, meaning that a “dangerous” burst of heating will be unleashed that will push the world to be 1.5C hotter than it was, on average, in pre-industrial times within the 2020s and 2C hotter by 2050, the paper published on Thursday predicts.

This alarming speed-up of global heating, which would mean the world breaches the internationally agreed 1.5C threshold set out in the Paris climate agreement far sooner than expected, risks a world “less tolerable to humanity, with greater climate extremes”, according to the study led by Hansen, the former Nasa scientist who issued a foundational warning about climate change to the US Congress back in the 1980s.

Yes, that’s right, the guy who kicked off this whole global warming boondoggle in the first place, is now warning us that it’s much, much worse than even he thought. Mann claims that ‘it’s bad enough’ and that we don’t need Hansen’s latest cry of alarm based on some decidedly dodgy science, but he’s missing the point (probably intentionally). Hansen is seeding the public consciousness and the minds of politicians with the notion that global warming is accelerating rapidly, right now, at this very moment and that this means we will break through the 1.5C supposed threshold of ‘dangerous’ (nay, catastrophic) warming much sooner than expected . . . . . . unless we destroy our industries and way of life much more quickly and we hack the atmosphere by injecting billions of tons of cooling aerosols into it, with dangerously unpredictable consequences. The man is a menace. He’s made a Faustian pact with the Devil, or Gates (or maybe they’re one and the same). The irony is, Hansen accuses the entire human race of making this Faustian pact:

“We would be damned fools and bad scientists if we didn’t expect an acceleration of global warming,” Hansen said. “We are beginning to suffer the effect of our Faustian bargain. That is why the rate of global warming is accelerating.”

Hansen is no damned fool and he’s probably not even a bad scientist, in the technical sense. But he is bad, bad to the bone, for advocating geo-engineering as a solution to an imaginary global environmental crisis, for deliberately obfuscating the most probable cause of the recent acceleration in warming and for dishonestly conflating weather with climate. No respect here.

Jenkins, Allen et al have already told us why we might expect to break through the 1.5C limit sooner than expected - because of the Hunga Tonga volcano. But even Jenkins et al can’t get the results of their own study right; I mean, they’re only PhD scientists, you can’t expect them to do simple arithmetic can you? The authors state:

Over the five-year period 2022-2026, the light grey historical+SSP2-45 scenario has a 50% probability of 1.5°C-exceedence, which increases to 57% once the HTHH eruption is included (green).

Despite this, the HTHH eruption temporarily does increase the GMST anomaly over the next five years, while stratospheric water vapour concentrations are perturbed. Over this period HTHH increases the likelihood we observe our first 1.5°C year by around 7%.

NO, it’s not 7%, it’s 14%! Good grief. How can such an elementary error be overlooked by peer-reviewers of a Nature paper? Probability - even expressed as a percentage - is a quantity. If you increase a quantity of 50 by 7, then the percentage increase is 14%. A 50% chance can alternatively be expressed as a probability of 0.50. If this increases to 0.57, then the % increase is 14%. 14% is significant; 7% not so much. Anyway, griping aside, there you have it, in the existing scientific literature (Nature no less), the tacit admission that Hunga Tonga will increase the likelihood of reaching or surpassing the 1.5C threshold by 14% in the next 5 years, but Hansen would have us believe it’s because climate sensitivity is much higher than previously estimated and that, as he calls it, “The great inadvertent aerosol experiment” is heating the planet right now by virtue of the sudden disappearance of ship’s fuel emissions. Even Mann poo poo’s this notion:

There is no evidence that changes in ship-based aerosols have played any substantial role at all in recent warming trends.

Mann says that there’s no evidence for an acceleration in the global warming trend:

There is, furthermore, no statistical support for the claim that surface warming is currently accelerating. It is certainly true that the rate has increased since the 1970s, but that's related to changes in aerosol forcing at that time that are not relevant to the warming of the past few decades. Over the past few decades, there is no statistically-supportable evidence of an increase in the rate of surface warming. Surface warming has continued at a remarkably constant rate for the past few decades, as I recently showed in this thread on twitter (see plot below). The warming of the planet (and all of the worsening impacts associated with it including extreme weather events and intensified hurricanes) will continue until we bring carbon emissions to zero. The truth, once again, is bad enough.

He’s right; the trend is remarkably constant, as is the (time lagged) trend in global atmospheric CO2 concentration, which is miraculously proposed as the cause of the temperature trend. Mann recognises that Hansen’s uber-alarmism is not scientific and probably counter-productive, but he’s not giving up on the catastrophe narrative and he deliberately and dishonestly conflates a monotonic and modest global warming trend with extreme weather events. He also patently ignores the most likely cause of the very recent real acceleration in global warming, which qualifies as a global weather event basically, which is almost certainly due to Hunga Tonga.

Science and data be damned. In the squabble between ‘bad enough’ scientists and ‘it’s much worse than we thought’ scientists each plugging their own particular hobby horse, both are victims.