Climate models are wrong?
Climate models are mathematical representation of an enormously complex system. They are intended to project trends, not predict events. They are an imperfect but indispensable tool to gain an understanding of what we can likely expect in the future.
Casting doubt on the reliability of climate models is a common theme among climate skeptics who commonly claim that models are not accurate – and sometimes the “skeptics” are right. Though not in the way they’d have us believe.
Underestimating climate sensitivity
A key finding from new research published in the journal Nature suggests that previous models underestimate the sensitivity of climate to carbon dioxide. Conducted by the Centre of Excellence for Climate System Science at the University of New South Wales, the study focuses on cloud formation and its role in climate.
“Our research has shown climate models indicating a low temperature response to a doubling of carbon dioxide from preindustrial times are not reproducing the correct processes that lead to cloud formation,” says lead author professor Steven Sherwood.
“When the processes are correct in the climate models the level of climate sensitivity is far higher. Previously estimates of the sensitivity of global temperature to a doubling of carbon dioxide ranged from 1.5°C to 5°C. This new research takes away the lower end of climate sensitivity estimates, meaning that global average temperatures will increase by 3°C to 5°C with a doubling of carbon dioxide.”
With carbon dioxide levels now hovering at 400 parts per million (ppm) we are already well on our way to a doubling of CO2 from pre-industrial levels of about 270 ppm. In fact, according to Joe Romm of Climate Progress we are barrelling toward a tripling or even quadrupling of CO2 concentrations this century, 820 to 1100 ppm, given a business-as-usual pathway of carbon emissions.
Sherwood explains the research in further detail in this video:
Image credit: efilpera, courtesy flickr