Thursday, January 7, 2010

A bar chart look at CO2 Emissions

Yesterday, I commented on a cheeky political cartoon about C02 emissions from Feb 09. As a graduate student, I was told to read a tiny little 1954 book that has turned out to be an important part of my education as a skeptic: Huff's "How to lie with statistics".

Today, as part of my ongoing campaign to present a range of perspectives on climate change, I comment on two bar charts about C02 emissions.

Turn this bar chart on its side, and it looks like... a hockey stick. Hmmm. Top 12 emitters in 2002? US, China, Russia, Japan, India, Germany, UK, Canada, Italy, France, South Africa, Australia.

CAIT 7.0 offers another perspective on C02 Emissions. On page 3, the top 12 emitters in 2005/6 are summarized - Qatar, UAE, Bahrain, Kuwait, Luxembourg, Trinidad & Tobago, US, Australia, Canada, Saudi Arabia, Russia and Germany. But wait, where is China? Where is Japan?

Depending on the perspective, and the year, and how we look at the data, the "top 12 emitters" change - it depends on whether we are looking at total emissions or by capita. A different picture will emerge if we look at a computer model prediction of who the C02 emitter bad guys will be in 2020...

"Huffy" point to be made - how we collect data matters, how we read and represent and misrepresent data matters, and different visual and numerical representations can offer very different perspectives on an observed phenomena -- like the C02 emissions problem.

No comments: