We have made considerable progress in defining the ÒfingerprintsÓ of different forcings
1. Solar
3.
Well-mixed greenhouse gases
5. Sulfate aerosol particles
2. Volcanoes
4. Ozone
6. 1stfive factors combined
¡C/century
Santeret al., Climate
Change Science
and Policy, 2007
Detecting ÒsignificantÓ climate change
means showing that a given change in climate is unusual relative to some
yardstick that you have of ÒnormalÓ behavior.
If you feel hot, and measure a body
temperature of 102oF, then youÕve ÒdetectedÓ a fever - you know
that that this elevated temperature is outside the limits of ÒnormalÓ body
temperature.
But this measurement doesnÕt give you
the cause of the fever.
To deduce the cause, youÕll probably
need to undergo some more sophisticated tests - perhaps urine and blood
analyses, maybe even x-rays or CAT scans.
Once you have the results from these
tests, itÕs much easier to narrow down the potential causes of the fever.
This is attribution - the process of
establishing cause and effect.