This book’s concept is simple. It provides the data to understand the debates and options around the great issue of our times: climate change.

Our lifestyle is absolutely unsustainable: if everyone lived as we do, we would need three planet earths to support us. We need to decarbonise our energy supply. What’s more, with the UK now a net importer of gas after 30 years of exports, energy security – and, thus, energy efficiency – is a vital strategic issue.
 
So, can we wean the West off fossil fuels and still operate a modern economy that supports a modern lifestyle? Many departments are in the front line here, developing our national response to the challenge. And they are faced with many lobby groups, all wielding their own opinions and sets of statistics.

It’s not so much emissions of CO2 that perplex David MacKay, a Cambridge University physicist, as emissions of ‘twaddle’: assertions not backed up by a rigorous analysis of relevant data, and the misuse of statistics. So he’s written a book, aimed at the elected and unelected members of the government and Parliament.

The book calculates the energy consumption of our lifestyles and the potential energy output of the fossil- and renewable-powered generation technologies, using the common unit of kilowatt hours per person per day (kWh/p/d). So an average European citizen consumes a total of about 125kWh per day, much of it supplied by fossil fuels. Of this, personal motoring comprises about 40kWh/p/d; were we to cover 10 per cent of the entire UK landmass with wind farms, says MacKay, we would generate about half that amount.

MacKay goes on to look, for example, at the energy consumed by holiday flights (averaging 30kWh/p/d), food production (15kWh/p/d), and the consumption of goods (more than 48kWh/p/d). On the other side of the scale, he calculates that if we covered five per cent of the UK’s entire land area with photovoltaic cells, we could generate 50kWh/p/d; installing 10,000 offshore wind turbines would produce 4.4kWh/p/d; and a tidal power Severn barrier could generate 0.8kWh/p/d. The message is clear: very large areas would have to be dedicated to renewable power generation to collect the kind of amounts of energy that we consume. By contrast, fossil fuels are a very dense and compact source of energy.

Along the way, several myths are despatched. We learn that while 33,000 birds are killed by windmills each year in Denmark, one million are killed by cars and 55 million by cats; that leaving your phone charger plugged in for a year consumes as much power as boiling a half-filled kettle; that building a nuclear power plant emits 0.3 per cent of the CO2 emissions that it would take to generate the plant’s lifetime output using a fossil fuel power station.

With all this maths done for us, no-one taking part in the debate over the future of energy now has any reason for not knowing or understanding the basic numbers behind the arguments.

To make my own contribution to cutting twaddle emissions, I will be sending a copy of the book to the cabinet secretary and the permanent secretaries of the Departments for Communities and Local Government, Transport, and Energy and Climate Change. The debates may continue to be complex and full of difficult decisions, but at least the options will be much, much more clear.

Professor Michael J Kelly is the chief scientific adviser to the Department for Communities and Local Government, and a professor of technology at Cambridge University. Sustainable Energy can be downloaded via www.civilservicenetwork.com/links