We know global warming has been unprecedented in the past several hundred years. A new report from Oregon State and Harvard researchers goes much further back, reconstructing temperature over the past 11,300 years, from the time almost of the last ice age. It’s not a pretty sight.
Current temps (so far) aren’t ahistorical. It was this warm for a long period that extended from five to ten thousand years ago (the Early Holocene). What’s shocking is the speed of warming. The warmup from the ice age to the Early Holocene took about 2,000 years. Thanks to human industry it just took 50 years with no end in sight.
Commentary in the New York Times is here and here. The abstract from the research follows.
Surface temperature reconstructions of the past 1500 years suggest that recent warming is unprecedented in that time. Here we provide a broader perspective by reconstructing regional and global temperature anomalies for the past 11,300 years from 73 globally distributed records. Early Holocene (10,000 to 5000 years ago) warmth is followed by ~0.7°C cooling through the middle to late Holocene (<5000 years ago), culminating in the coolest temperatures of the Holocene during the Little Ice Age, about 200 years ago. This cooling is largely associated with ~2°C change in the North Atlantic. Current global temperatures of the past decade have not yet exceeded peak interglacial values but are warmer than during ~75% of the Holocene temperature history. Intergovernmental Panel on Climate Change model projections for 2100 exceed the full distribution of Holocene temperature under all plausible greenhouse gas emission scenarios.