Back in 2006 I wrote an Editor’s Choice called “What did you do about climate change Mum?” (BMJ 2006;332:10 June, doi:10.1136/bmj.332.7554.0-f). It suggested that doctors might start measuring their carbon footprint. The most interesting thing about this short piece was the response it received on bmj.com (www.bmj.com/cgi/eletters/332/7554/0-f). What was this stuff doing in a medical journal? What was I doing uncritically accepting the propaganda of the global warming lobby?

Things have changed since then. WHO’s director general Margaret Chan has called climate change the biggest public health challenge of the 21st century. And last week the UN and Red Cross warned that a …