At the heart of the climate-change debate is a paradox: we've never had more information about our changing climate, but surveys show that the public are, if anything, getting less sure they understand what’s going on.

This BBC TV programme (2nd March 2015) provided a new perspective on the subject, presented by mathematicians Dr. Hannah Fry, Prof. Norman Fenton and Prof. David Spiegelhalter.

It honed in on just three key numbers that clarify all the important questions around climate change. The stories behind these numbers involve an extraordinary cast of characters, almost all of whom had nothing to do with climate change, but whose work is critical to our understanding of the climate.

The three numbers are: 0.85 degrees (the amount of warming the planet has undergone since 1880), 95 per cent (the degree of certainty climate scientists have that at least half the recent warming is man-made), and 1 trillion tonnes (the total amount of carbon we can afford to burn - ever - in order to stay below 'dangerous levels' of climate change). We have already burned half of that.

Understanding how scientists came up with these three numbers gives a unique perspective on what we know about the past, present and future of our changing climate.

I felt I had to watch it twice before I could take it all in, but I found it a fascinating programme.

It can be viewed until 5th April on BBC iPlayer

P.O’B