http://www.metoffice.gov.uk/climatechange/news/latest/clouds.html
"New research has added more evidence to suggest low-level clouds may be reduced by climate change, causing further global warming. The study, published in Science, relied on the Met Office’s climate model as the only one which accurately reflects real-life observations. The findings also support many years of Met Office research looking at how climate change may affect clouds and how clouds may affect climate change.
Low-level clouds, such as stratocumulus, play a vital role in keeping the Earth’s climate cool by reflecting sunlight. Because they are so important, climate researchers have been studying how they might react to a changing climate on a regional scale. However, this remains one of the biggest sources of uncertainty in understanding future climate change."
The research
"If global warming means more low-level cloud develops, then more sunlight would be reflected, helping cool the planet and offset climate change — known as a ‘negative feedback’. If the opposite occurs and we see less low-level cloud, more sunlight would get through and the planet would heat even more, further escalating the warming — known as a ‘positive feedback‘.
The new research studied whether our warming climate will result in more or less low-level cloud by examining changes over the north-east Pacific in real-life observations and computer generated climate models. Analysis from observations showed cloud was affected by regional temperature changes and shifts in the atmospheric circulation of air and water.
They then studied 18 of the world’s leading climate models to see which of them accurately reflected this pattern. This method provides a new way to date of testing how realistically climate models represent low-level cloud changes and, therefore, which we can most rely on. The researchers found only two models fitted with their observations — including the Met Office’s HadGEM1. Further analysis led them to rely only on the Met Office model, which employs the sophisticated atmospheric simulations required.
Our model showed low-level cloud cover over the test area decreased under global warming, creating a positive feedback. This is apparently due to an increase in sea-surface temperatures and weakening of the large-scale atmospheric circulation."
To be fair, they state at the end:
"While this provides a significant step in understanding the link between low-level cloud and climate change, as well as proving the robustness of the Met Office model, there are still no conclusive answers."
Mat Collins then goes on to say:
“There is still much work to be done before the uncertainty in this area of climate modelling can be fully eliminated.We’ve been researching the relation between clouds and climate change for more than a decade. It’s not surprising our model came out top because of the amount of effort we have put into developing the model, but there is still a long way to go. This research is only part of the jigsaw and one more test of the models. There are still a lot of questions to answer before we can be sure we’re getting this absolutely right.”
Hey Matt, try harder on the seasonal forecasts first!