Here's a very clear, readable and well-researched site on how to respond to climate change skeptics. A great example of what you will find runs as follows:
So 2005 was a record year, one really warm year or two is not global warming.
This kind of objection only indicates an unfamiliarity with the actual long term temperature record and is just asking for a few good temperature facts, so let 'em have it!
2005 breaking the record is not convincing? Let's see then, how about:
- every year since 1992 has been warmer than 1992
- the ten hottest years on record occurred in the last 15
- every year since 1976 has been warmer than 1976
- the 20 hottest years on record occurred in the last 25
- every year since 1956 has been warmer than 1956
- every year since 1917 has been warmer than 1917
The five year mean global temperature in 1910 was .8oC lower than the five year mean in 2002. This and all the above come from the analysis by NASA GISS here: