Warmist Chris Rapley suggests that 100 ppm changes in CO2 caused fluctuations between Ice Ages and interglacials?!

BBC News - Climate change 'grave threat' to security and health

Climate change poses "an immediate, growing and grave threat" to health and security around the world, according to an expert conference in London.

Officers in the UK military warned that the price of goods such as fuel is likely to rise as conflict provoked by climate change increases.
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Without urgent action, carbon emissions could rise to levels that should cause major alarm, said Chris Rapley, professor of climate science at University College London.

Already, he noted, the atmospheric concentration of carbon dioxide has risen to about 380 parts per million [ppm] - whereas in the millions of years before the pre-industrial era, it fluctuated between about 180ppm during Ice Ages and about 280ppm in the warm interglacial periods.

"If we don't do something, then at the rate we're going, carbon emissions will continue to accelerate, and the atmospheric concentration is not going to be 450ppm or 650ppm by the end of the century, but 1,000ppm," he said.

"That is 10 times the difference between an Ice Age and an interglacial; and you have to be a pretty huge optimist to think that won't bring major changes."