How bad are bananas? : the carbon footprint of everything
by Mike Berners-Lee (not to be confused with Tim Berners-Lee who invented the World Wide Web)
This is an non-technical look at how our daily activities may contribute to global warming.
There is no one area of our lives that is especially responsible for our carbon footprint. It's a combination of 8% this and 5% that. Cars are probably over-emphasized as the main cause of global warming. There is no main cause. Agriculture is significant, especially raising cows and sheep. Electricity generation is very significant, of course. Home heating is significant. So is air travel. (Emissions at higher altitudes are particularly problematic.)
Some things that are promoted as low carbon, such as burning wood, or running diesel engines, actually contribute significantly to global warming in ways other than carbon dioxide emissions.