The key take - home conclusion is that the rate and magnitude of recent global warmth appears unprecedented for at least the past 4,000 years and the rate at least the past 11,000. (dotearth.blogs.nytimes.com)
It is not any one proxy, but the agreement among them, that provides the most convincing evidence that the recent global warmth is very unlikely to be due to natural causes. (history.aip.org)
Current spatial coverage, temporal resolution and age control of available Holocene proxy data limit the ability to determine if there were multi-decadal periods of global warmth comparable to the last half of 20th century. (ipcc.ch)