The recording of my Software Engineering for the Planet talk is now available online. Having watched it, I’m not terribly happy with it – it’s too slow, too long, and I make a few technical mistakes. But hey, it’s there. For anyone already familiar with the climate science, I would recommend starting around 50:00 (slide 45) when I get to part 2 – what should we do?

[Update: A shorter (7 minute) version of the talk is now available]

The slides are also available as a pdf with my speaking notes (part 1 and part 2), along with the talk that Spencer gave in the original presentation at ICSE. I’d recommend these pdfs rather than the video of me droning on….

Having given the talk three times now, I have some reflections on how I’d do it differently. First, I’d dramatically cut down the first part on the climate science, and spend longer on the second half – what software researchers and software engineers can do to help. I also need to handle skeptics in the audience better. There’s always one or two, and they ask questions based on typical skeptic talking points. I’ve attempted each time to answer these questions patiently and honestly, but it slows me down and takes me off-track. I probably need to just hold such questions to the end.

Mistakes? There are a few obvious ones:

  • On slide 11, I present a synoptic view of the earth’s temperature record going back 500 million years (it’s this graph from wikipedia). I use it to put current climate change into perspective, but also also to make the point that small changes in the earth’s temperature can be dramatic – in particular, the graph indicates that the difference between the last ice age and the current inter-glacial is about 2°C average global temperature. I’m now no longer sure this is correct. Most textbooks say it was around 8°C colder in the last ice age, but these appear to be based on an assumption that temperature readings taken from ice cores at the poles represent global averages. The temperature change at the poles is always much greater than the global average, but it’s hard to compute a precise estimate of global average temperature from polar records. Hansen’s reconstructions seem to suggest 3°C-4°C. So the 2°C rise shown on the wikipedia chart is almost certainly an underestimate. But I’m still trying to find a good peer-reviewed account of this question.
  • On slide 22, I talk about Arrhenius’s initial calculation of climate sensitivity (to doubling of CO2) back in the 1880′s. His figure was 4ºC-5ºC, whereas the IPCC’s current estimates are 2ºC-4.5ºC. And I need to pronounce his name correctly.

What’s next? I need to turn the talk into a paper…