Nature CLOUD Study Author: ‘The Climate May Be More Sensitive Than Previously Thought’


New research from the CERN laboratory in Switzerland suggests that the climate’s sensitivity to carbon dioxide may be higher than expected.

CERN is the world’s leading particle physics laboratory. In 2011, we reported on their Cosmics Leaving Outdoor Droplets (CLOUD) experiment, which used a special cloud chamber to examine whether their was a link between galactic cosmic rays and cloud formation. This and other research show “cosmic rays play a minor role in cloud formation, and have not contributed in any significant way to the global warming over the past 50 years.”

The CERN news release explains that the new research looked into how “aerosols – tiny solid or liquid particles suspended in the air” form, which matters because “aerosols cause a cooling effect by reflecting sunlight and by seeding cloud droplets.” The two key findings:

  • “minute concentrations of amine vapours combine with sulphuric acid to form aerosol particles at rates similar to those observed in the atmosphere.”
  • “ionising radiation such as the cosmic radiation that bombards the atmosphere from space has negligible influence on the formation rates of these particular aerosols.”

Amines are atmospheric vapors that are closely related to ammonia and emitted by natural sources and human activities such as farming cattle and other animals (aka animal husbandry). They are “responsible for odours emanating from the decomposition of organic matter that contains proteins.” The release notes:

The measured sensitivity of aerosol formation to amines came as a surprise, and points to a potentially significant climate cooling mechanism.

Why does this matter? The UK Independent talked to research team leader Jasper Kirkby:

The global average temperature on land and sea rose by 0.85C from 1880 to 2012, the IPCC said in a major report last month. The fact that amines are produced by animal husbandry means that humans are responsible for a previously unknown cooling effect on the planet. So the overall man-made “forcing” of the climate -– once greenhouse gases are taken into account -– may actually be less than thought.

And that could be bad news because, Professor Kirkby said, it suggested “the climate may be more sensitive than previously thought”. “If there’s been more cooling from aerosols than thought at the moment then this temperature rise will have resulted from a smaller forcing – or change – than previously thought,” he said. “That would mean the projected temperatures this century for a doubling of carbon dioxide may be bigger than current estimates.”

Notwithstanding some research that has suggested climate sensitivity is on the low side, considerable research suggests that the Earth system’s actual sensitivity to CO2 is on the high side: