1. Natural factors:
- orbital changes only
- solar variation
- volcanic eruptions
- all three natural factors together.
2. Human activity:
- land use changes
- ozone changes
- aerosols
- greenhouse gas accumulation
- all human activity together.
3. Natural factors and human activity combined.
The graphic is worth bookmarking for showing to (normal) people to illustrate how human activity has led to the large rise in global surface temperatures since 1880. There's not much point showing it to deniers, the sort of people who relish articles like the one by David Burton at WUWT the other day (archived here).
You might remember David. He's the chap who spent 547.5 days and nights fretting about Doran & Zimmerman (2009) before coming up with a number-fudging brainwave (It was not a brainwave, it was nothing but Dave's bad arithmetic.)
You might remember David. He's the chap who spent 547.5 days and nights fretting about Doran & Zimmerman (2009) before coming up with a number-fudging brainwave (It was not a brainwave, it was nothing but Dave's bad arithmetic.)
