3.5 mil years ago, summer temps were ~8°C warmer than today, CO2 was ~400 ppm

Two recent studies on past temperatures… Pliocene Warmth, Polar Amplification, and Stepped Pleistocene Cooling Recorded in NE Arctic Russia Understanding the evolution of Arctic polar climate from the protracted warmth of the middle Pliocene into the earliest glacial cycles in the Northern Hemisphere has been hindered by the lack of continuous, highly resolved Arctic time…

Last 12 Years Were Among 13 Warmest On Record, World Meteorological Organisation Confirms

By Alex Kirby / Climate News Network.

The year just past confirmed the Earth’s warming trend, which will continue and is reason for concern, says the World Meteorological Organisation.

LONDON, 2 May – Last year was among the ten warmest years since records began more than 160 years ago, the World Meteorological Organisation says.

The WMO says 2012 was the ninth warmest year recorded since 1850, and the 27th consecutive year in which the global land and ocean temperatures were above the 1961-1990 average.

The WMO Secretary-General Michel Jarraud said the continuing warming was cause for worry, and that it was on track to continue.