Thread: Sweltering in this heatwave? Me too. And as this article makes clear, it's largely down to climate change. But here's how climate change 'skeptics' are going to try and play it - and how to not let them (1/n) theguardian.com/environment/20… 
..the go argument of climate change 'skeptics' (more on that term later) is to argue that 'computer models' are basically toys with no predictive value, a blackbox that means nothing. They'll fixate on paragraphs like this. So why is that wrong? (2/n)
..so my background - I work in mathematical modelling of physical phenomena (cancer growth, radiation dose, etc). Climate 'skeptics' pivoting on a devious mistruth. Broadly speaking, there are 2 major classes of model: phenomenological and mechanistic models. I'll explain (3/n).
..phenomenological models describe data, but mightn't be derived from theory. They might arise from fitting some function to a empirical data. A mechanistic model, by contrast, is built from first principles upwards. The underlying physics are mainly understood in this case (4/n)
..Climate change is HUGELY mechanistic. French Polymath Joseph Fourier hypothesized human impact on climate in 1827: effects of greenhouse gases demonstrated experimentally by Irish Physicist John Tyndall in 1864! That we shape climate isn't new info (5/n) blogs.scientificamerican.com/plugged-in/why…
..the whole objection to mathematical models in climate change is based on a deliberate ignorance of the fact these models arise from *known* physical laws. We need powerful computer modelling to follow them through to their conclusion, but the underlying physics is sound (6/n)
..incidentally, mathematical modelling underpins everything The car you drive was physically simulated, the planes you travel too, a patient's radiotherapy dose is simulated. All based on known physics. But you don't hear climate change 'skeptics' decrying these, do you? (7/n)
..the related gambit is to claims "well scientists can't even predict the weather for next month, how could they predict climate, eh?!" - which is either ignorant or disingenious; weather may be chaotic, but climate is a stable average over time. It's distraction. (8/n)
..we've LONG known humans hugely impact climate, and we can quantify how much with a mixture of observation and modelling, and constant refinement - exactly as science *should* proceed. Here's a nice bit on why we know how much human activity matters (9/n) skepticalscience.com/climate-models…
..so the climate is changing, and we're driving it. But 'Skeptics' try to distract from the science, or attack climate scientists like @MichaelEMann or communicators like @ProfBrianCox ... why is that? Because they're not skeptics - they're rank denailists. This matters...(10/n)
..being skeptical is a laudable thing: skepticism is crucial to the scientific method. But if you insist on DENYING evidence, or ignoring that which doesn't fit your narrative, this is not skepticism. It's something more odious, as I wrote here (11/n) theguardian.com/science/2014/f…
..to conclude, mathematical models of climate change are based on solid physics. The overwhelming evidence says we're driving it, and we cannot afford to deny this reality. Don't let deniers muddy the water - the consensus is clear. Fin. (n = 12, 12/n)
