A couple of years ago the question was asked “When will it start cooling?” Of course solar denialists misconstrued this innocent enquiry. There is no doubt – we all know that lower solar irradiance will result in lower temperatures on this planet. It is a question of when. Solar activity is much lower than it was at a similar stage of the last solar cycle but Earthly temperatures have remained stubbornly flat. Nobody is happy with this situation. All 50 of the IPCC climate models have now been invalidated and my own model is looking iffy.
Friss-Christenson and Lassen theory, as per Solheim et al’s prediction, has the planet having a temperature decrease of 0.9°C on average over Solar Cycle 24 relative to Solar Cycle 23. The more years that pass without the temperature falling, the greater the fall required over the remaining years of the cycle for this prediction to be validated.
The question may very well have been answered. David Evans has developed a climate model based on a number of inputs including total solar irradiance (TSI), carbon dioxide, nuclear testing and other factors. His notch-filter model is optimised on an eleven year lag between Earthly temperature and climate. The hindcast match is as good as you could expect from a climate model given the vagaries of ENSO, lunar effects and the rest of it, which gives us a lot of confidence in what it is predicting. What it is predicting is that temperature should be falling from just about now given that TSI fell from 2003. From the latest of a series of posts on Jo Nova’s blog:
The model has temperature falling out of bed to about 2020 and then going sideways in response to the peak in Solar Cycle 24. What happens after that? David Evans will release his model of 20 megs in Excel in the near future. I have been using a beta version. The only forecast of Solar Cycle 25 activity is Livingstone and Penn’s estimate of a peak amplitude of seven in sunspot number. The last time that sort of activity level happened was in the Maunder Minimum. So if we plug in TSI levels from the Maunder Minimum, as per the Lean reconstuction, this is what we get:
This graph shows the CET record in blue with the hindcast of the notch-filter model using modern TSI data in red with a projection to 2040. The projected temperature decline of about 2.0°C is within the historic range of the CET record. Climate variability will see spikes up and down from that level. The spikes down will be killers. The biggest spike you see on that record, in 1740, killed 20% of the population of Ireland, 100 years before the more famous potato famine.
I consider that David Evans’ notch-filter model is a big advance in climate science. Validation is coming very soon. Then stock up on tinned lard with 9,020 calories per kg. A pallet load could be a life-saver.
David Archibald, a Visiting Fellow at the Institute of World Politics in Washington, D.C., is the author of Twilight of Abundance: Why Life in the 21st Century Will Be Nasty, Brutish, and Short (Regnery, 2014).
For fairness and to promote a fuller understating, here are some replies from Joanne Nova