Our planet’s pre-industrial climate may have been cloudier than presently thought, shows CERN’s CLOUD experiment in two papers published today in Nature
CLOUD shows that organic vapours emitted by trees produce lots of aerosol particles in the atmosphere when there’s no sulphuric acid – a main product of burning fossil fuels.
Previously, it was thought that sulphuric acid was essential to initiate the formation of these aerosol particles but the new research shows that these so-called biogenic vapours are also key to their growth, and can help them grow up to sizes where they can seed clouds.
“These results are the most important so far by the CLOUD experiment at CERN,” said CLOUD spokesperson, Jasper Kirkby. “When the nucleation and growth of pure biogenic aerosol particles is included in climate models, it should sharpen our understanding of the impact of human activities on clouds and climate.”
The Intergovernmental Panel on Climate Change (IPCC) considers that the increase in aerosols and clouds since pre-industrial times represents one of the largest sources of uncertainty in climate change. The CLOUD experiment is designed to better understand such processes.
CLOUD has also found that ions from galactic cosmic rays strongly enhance the production rate of pure biogenic particles – by a factor 10-100 compared with particles without ions. This suggests that cosmic rays may have played a more important role in aerosol and cloud formation in pre-industrial times than in today’s polluted atmosphere.
http://home.cern/about/updates/2016/05/cloud-shows-pre-industrial-skies-cloudier-we-thought
A quiet sun diminishes the magnetosphere, which then lets more high energy cosmic rays rain down on the earth, with the potential to create more clouds, thus more global cooling. This could be the mechanism that results in mini-ice-ages. Your thoughts.
The Next Grand Minimum 
Pleased to see Svensmark’s theories being confirmed by CERN
Checked through all of their references and carried out a search on the text.
I couldn’t find a single mention of Svensmark
I’m having trouble with “The pre-industrial climate has much less contrast than it has with today” @2:08 in the video clip.
Does this mean that in the pre-industrial plants were more responsible for the cloud cover.
Just a thought:
If the plants produce more clouds that will cool the planet, which leads than to the plants to grow less. This in turn would reduce the cloud cover and the planet would warm up.
I guess you call this a natural cycle.
What?? I thought global warming science was settled?
Science is never settled, it is an ongoing process of discovery.
Yes ”science is settled” for airport heat, LIA, vineyards in England and Vikings on Greenland” gospel… Now the phony skeptics don’t have plan B… must carry the smelly diapers and brown paper bag over their heads… Holocene, Eocene, Crapocene… amennnn…Hi Russ I hope you are in better health than I’m – winter started here in the tropics, and I resemble 3 year old,snotty kid… cheers!