With interests and achievements in fields ranging from neural networks to software for disabled users and from information theory to energy policy, David stood out as a polymath.

Within the arena of climate change he made important contributions to developing the UK's energy policy through his time as chief scientific advisor in the Department of Energy and Climate Change (DECC), but he is better known through his 2008 book: Sustainable Energy Without the Hot Air.

This has been downloaded for free over half a million times and shows the limits and options for renewable energy technologies as we seek to decarbonise our societies. His ability to clearly communicate renewable energy issues is amply illustrated in the video “How many lightbulbs?”.

The inaugural CCLS 2017 lecture series occurred near to the first anniversary of David's death. Our choice of “Climate Numbers in Context” was a tribute to his achievements and inspiration within the areas of communication and social justice, as well as the idea that individual measures need to “add up” to reach an overall climate change goal.