Extreme weather
The IPCC committee clearly reported that there was no observable trend in either the frequency or intensity of extreme weather that could be attributed to anthropogenic CO2, and that much more data would need to be available before such a determination could be made.
Everyone likes cherries :-)
The thing that always puzzles me about reports of changes in animal populations caused by climate change is how they actually make the determination that it's climate change that's responsible. I'd have thought that for the most part you can say that there's correlation, but causation? Given the increase in temperatures over the last 19 years, which would be what, ~0.1c? It's hard to believe that any butterfly would be affected by a change that small, when the average day/night temperature shift is probably 50x greater, let alone seasonal variation.
What about development, crop spraying, shift in predator populations, butterfly collectors, planting changes and disease. Getting a climate signal from that lot. Wow.
Not saying climate change isn't the cause, just that I find it hard to believe they're able to conclusively prove it.