Predicting the future based on the past

It is August, the Northern Hemisphere summer. It gets warm in summer and some summers are warmer than others. Having lived there for a number of years it all seemed to depend on whether the winds were predominantly from the Sahara Desert or not.

Yes, the Gulf Stream moved a few degrees north or south from year to year and that had an effect as well. Sometimes many factors combined and that produced even hotter summers, heatwaves even. In the winter other factors combined to blanket the U.K in snow for a few days, (something else not normal? but that does not advance the cause so we will ignore that.)

2018 was one of these heatwave years so the papers rolled out of ‘academia’ blathering on about “Hothouse Earth”.? The media loved it.? Article upon article about how we are all going to fry and there will be 60m of sea-level rise etc.

We have covered the ’60’ metre number before.? It requires every gram of ice in Antarctica to melt in order for the sea to rise 58 metres. And, yes, the maths is quite correct. But after that story was published, even the warmist National Geographic covered the new record for the coldest temperature measured on earth, minus 98C, recorded in Antarctica.

To get all the ice melted would thus require that the earth’s current average temperature rise by close to 100C.? That certainly would be a ‘hothouse earth’ and is quite clearly impossible.

Checking the maths and logic does not seem to be a strong point in the media or in some of the papers from ‘academia’ and another wonderful paper has just been published purporting to show that climate change is going to get hotter.? The media have jumped on it with glee. See Stuff.

Before we look at the paper though, as an aside, has anyone ever seen a reference to ‘climate change’ that implied the ‘change’ could be getting cooler?? It intrigues me that ‘change’ is only ever in one direction – warmer.

But back to the recent paper. Here is the abstract in full: Quote.

A novel probabilistic forecast system predicting anomalously warm 2018-2022 reinforcing the long-term global warming trend

In a changing climate, there is an ever-increasing societal demand for accurate and reliable interannual predictions. Accurate and reliable interannual predictions of global temperatures are key for determining the regional climate change impacts that scale with global temperature, such as precipitation extremes, severe droughts, or intense hurricane activity, for instance. However, the chaotic nature of the climate system limits prediction accuracy on such timescales. Here we develop a novel method to predict global-mean surface air temperature and sea surface temperature, based on transfer operators, which allows, by-design, probabilistic forecasts. The prediction accuracy is equivalent to operational forecasts and its reliability is high. The post-1998 global warming hiatus is well predicted. For 2018?2022, the probabilistic forecast indicates a warmer than normal period, with respect to the forced trend. This will temporarily reinforce the long-term global warming trend. The coming warm period is associated with an increased likelihood of intense to extreme temperatures. The important numerical efficiency of the method (a few hundredths of a second on a laptop) opens the possibility for real-time probabilistic predictions carried out on personal mobile devices. End of quote.

It starts off well.? The climate changes, yup always has, always will.? Society would like to have accurate and reliable predictions.? We surely would, we are heartily sick of “the models say” nonsense.

Then the wheels fall off and the bias appears. Scaling up temperatures causes “precipitation extremes, severe droughts, or intense hurricane activity” etc.

Oops, sorry, wrong graph …

No, not that one either!? Moving on …

A little bit of truth sneaks in, “the chaotic nature of the climate system limits prediction accuracy on such timescales” but we will box on regardless as we have a ‘novel’ system based on ‘transfer operators‘ which allow ‘probabilistic forecasts’.? This has a prediction accuracy?equivalent to operational forecasts and its reliability is high.??

Excellent. The prediction accuracy of operational weather forecasts in New Zealand is ‘reliably’ close to zero for anything more than a few hours ahead.

They then pat themselves on the back that the post-1998 global warming hiatus was “well predicted”. Yes, and I can reliably predict, with 100% accuracy, all past winning Lotto numbers.

Their conclusion is that the ‘probabilistic forecast’ for 2018 – 2020 is going to be warmer than the ‘forced trend’ of global warming as it will “reinforce the long-term global warming trend.”

Spoiler Alert:? There is no significant long-term ‘forced’ global warming trend.

Then we got the really exciting news, “the possibility for real-time probabilistic predictions carried out on personal mobile devices.

Give them a couple of weeks and there will be ‘an app for that’. We will all be able to accurately predict things that happened in the past and make probabilistic determinations about a warmer future, as increasing warmth will already be factored into the app – oh goody!