March 22nd, 2015
Econintersect: The BBC has a new documentary "Climate Change by Numbers BBC Documentary 2015" which is a review by three mathematicians of the data and methodology used in the study of climate trends and changes. One thing you will learn is the reason that 1880 is the date from which sea temperature reference data is used in modern climatology. You will also learn why the assumption of the accuracy of that data is problematic. In addition you will learn how mathematics is used to "clean" spurious fluctuation or data noise - and how that creates questions of bias and objectivity, giving rise to skeptics and "deniers".
In addition to quality issues for data there is also a continuity problem. Some data is missing from different measuring points and the measuring points are not uniformly uniformly distributed on the earth's surface. For example, there are very few surface measurement points in places like the Sahara and the arctic. Again mathematics is applied to improve uniformity. In this case you will learn that the mathematics is the same as used by gold miners to map gold deposits.
The question of use of models is discussed which is one of the focal points of critics of climatology research.
By the end the film explains why three numbers are at the core of climate change controversy: These are 0.85%, 95% and 1 trillion tonnes.
The summary from YouTube:
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.
This documentary is available for viewing only through 31 March 2015.