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Climate Change by Numbers

A look at three key numbers that clarify the important questions on climate change, giving a unique perspective on what we know about the past, present and future of our climate.

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

This programme aims to remedy that, with a new perspective on the whole subject. Presented by three mathematicians - Dr Hannah Fry, Prof Norman Fenton and Prof David Spiegelhalter - it hones 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)
1 trillion tonnes (the total amount of carbon we can afford to burn - ever - in order to stay below 'dangerous levels' of climate change)

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.

1 hour, 15 minutes

Last on

Sun 31 Oct 2021 00:15

Music Played

Timings (where shown) are from the start of the programme in hours and minutes

  • 00:10

    Max Richter

    H In New England

  • 00:30


    Bullet Proof

  • 00:38

    Jon Hopkins

    The Low Places

  • 00:40

    Django Django


Also watch Climate Change: A Horizon Guide

Also watch Climate Change: A Horizon Guide

Using the unique BBC archive, Helen Czerski reveals how our understanding of climate has evolved over the last 50 years.


Role Contributor
Presenter Hannah Fry
Presenter Norman Fenton
Presenter David Spiegelhalter
Producer Alex Freeman
Executive Producer Jonathan Renouf


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