Anthony Watts suggested today that we could use the Cretaceous Period as an analogue for a 2°C warmer world. Excellent idea, we can use that warm period from the past to test how well climate models perform. If they perform well, it will increase the credibility of the model projections for the 21st Century. It’s is such a good idea that someone has already done it.

Oh wait, that not what he means. Watts thinks we can use the Cretaceous as an analogue for what it will be like to live in a 2°C warmer world.

Was the Cretaceous too warm for Earth’s diverse species? Absolutely not – the Cretaceous hosted a bounty of life and biodiversity, the emergence of the first flowering plants, the first appearance of our mammal ancestors. The Dinosaurs dominated the warm Cretaceous for 80 million years, a long period during which life flourished.

Cretaceous species had millions of years to adapt to warm conditions. Our current biota has perhaps a century. Species will need to adapt to the changing climate or migrate potentially hundreds of kilometres, often across human dominated landscapes, to remain in their ecological niche. Rates of climate change can be more important that the magnitude of change for biodiversity.

The dinosaurs didn’t care much about the high eustatic sea levels in the Cretaceous as they hadn’t built cities and nuclear power stations by the sea. Has Watts not noticed that the only dinosaurs are those that continue to promote the burning of fossil fuels, labouring under the delusion that they emit “harmless CO2 emissions.”