Copenhagen: Food insecurity

A sobering presentation by Marshall Burke of Stanford on future agriculture. He and colleagues looked at historical climate and yield data for various crops in various parts of the world and projected the relationship they found into various future climates as found in the IPCC. As the IPCC itself reported, much of the tropics did badly in this analysis, and the worst performer was maize in southern Africa which was down in yield by about 30% by 2030.  Read more

Copenhagen: Who’s reporting?

I had a look this morning at a breakdown of the press registration at this conference by country. Clear winners are Denmark and the UK, with 40 or so people each. Both of those are inflated figures, because some third-country and international organisations are covering the meeting out of Copenhagen and London (Japanese TV stations are listed as UK, for example, as is Al Jazeera English). But still there is a lot of genuine UK interest: national papers and the BBC. And the locals are out in force.  Read more

Copenhagen: Has the Amazon tipping point tipped?

It appears that the action on Wednesday afternoon was where I was not: in the session on tipping points. Chris Jones of the Met Office’s Hadley Centre presented some studies of the Amazon (abstract in pdf) that have caused a big media stir. The studies suggest that a) there is a threshold level of warming beyond which much of the Amazon forest is committed to die back (probably being replaced by savanna) and b) that for significant parts of the forest that threshold is alarmingly low. Indeed it is quite possibly either unavoidable in the near future or already dwindling in the rear-view mirror.  Read more

Copenhagen: Twittering geoengineering

There’s a technical session on geoengineering at the meeting today, and I thought I’d try twittering from it. Since this is a personal experiment and may not pan out, I’ll be using my personal twitterfeed,, not the naturenews feed.  Read more

Copenhagen: Greenland tipping points

Like Olive, I’m at the Climate Change Congress in Copenhagen. My first impression is that it’s like a scaled up version of the Avoiding Dangerous Climate Change meeting that took place in Exeter in 2004: a venue for up-to-date (ie more recent than the most recent IPCC) science to be presented in a polciy relevant atmosphere. And by odd coincidence the first paper I heard presented was on a topic that in my mind is quite strongly linked to that Exeter meeting.  Read more

Geoengineering by the numbers

Geoengineering by the numbers

Cross-posted from Heliophage A very useful paper (abstract|pdf|discussion space) comes out today in Atmospheric Chemistry and Physics by Tim Lenton and his student Naomi Vaughan. Tim told me when I was reporting the Andy Ridgwell paper on leaf albedo (Nature story|blog entry) that he’d become pretty interested in evaluating geoengineering schemes, and was setting up a group at the University of East Anglia to assess them. This paper presumably represents the first fruits of that interest, providing a ranking of most of the geoengineering schemes proposed in the literature in terms of the amount of radiative forcing they can provide.  Read more