the problem with "actual changes" is direct causal linking to the effects and sometime even verification of the change. i dont know if he addresses such concerns in his examples. a couple ive read about in popular scientific media are the Himalayan glaciers which were supposed to be receding...
i think the correct place for scepticism can be summed up with this key finding: Global surface temperature change for the end of the 21st Century is "likely" to exceed 1.5C relative to the period 1850-1900. Likely is meant as 66% possibility. the last report in 2007 said the lower bound was...