Climate change in focus at University of Hong Kong exhibition

Mankind may have been around for just four-thousandths of the earth's 4.5 billion year history but the last 300 years of human activity have been enough to alter climate patterns.

A new exhibition at the University of Hong Kong's Stephen Hui Geological Museum traces the history of climate change back 65 million years to the start of the Cenozoic Era - the advent of the age of mammals, which continues into the present.

On display will be a range of paleoclimate "proxies", from 3,000 year-old tree rings and marine sediments to fossilised marine micro-organisms and mammals, all of which serve as organic "records" of the planet's climatological past.

"It is important to look to the past to help understand how human activity will impact climate change in the future," said museum curator Dr Petra Bach. "We study the long-term trends rather than the short-term trends."

A look into the earth's Cenozoic past will reveal short-term "abrupt climate changes" when temperature and CO2 levels rise rapidly, sometimes causing highly disruptive effects including extinctions of certain species, she added.

And carbon dioxide concentrations have risen steeply since the beginning of the industrial revolution with atmospheric CO2 levels increasing from 280 parts per million to 400 in just under three centuries.