"Abrupt climate change" was discovered by accident by Russell Coope (1930-2011), over 50 years ago.
More recently he said:
"We are messing with the trigger that causes climate change....the outcome is likely to be ferocious."
In the 1950s, Russell Coope was a young geologist.
He was studying layers of sediment formed during the "Ice Ages", a time geologists call the Quaternary.
He spotted something unusual in a quarry in the English Midlands.
This is his own description of what he found ...
"I happened, entirely by accident, to visit a Quaternary gravel pit in which were exposed the spectacular bones of mammoth, woolly rhinoceros and bison.
Looking at their sediment matrix I was amazed to find enormous numbers of equally spectacular, if somewhat smaller, insect remains.
I was hooked instantly!
Particularly exciting to me was the fact that these insect fossils showed that Quaternary climates had changed abruptly.
Thus, at times, fully glacial climates gave place to temperate interglacial conditions within the span of one human lifetime."
A well-developed sequence of ice age deposits at Bridgwalton Quarry near Bridgnorth, Shropshire. (Photo: Dave Evans).
This was the first discovery of evidence that the climate can change really quickly.
His discovery was later confirmed by evidence from ice cores from the Greenland ice sheet.
So how does Russell Coope's method work?
Different beetles prefer different temperatures.
By identifying the overall collection of beetles in a layer of sand or gravel, Coope could tell what climate existed in that place, and how it changed.
This is slow, meticulous work - but beetles can be identified even if only wing cases survive, because they are unique for each species.
Experts still use Russell Coope's method.
This fossilised beetle is well preserved.
This particular fossil is of a diving beetle found in the La Brea Tar Pits in California.
“We know from ice cores in Greenland that large climate oscillations occurred during this time,” lead study author Gene Henry told Gizmodo. “We wanted to see if those climate oscillations had an imprint in circulation patterns.”