Where have all the Clouds gone and why care? - Highlighted Article

From: Watts Up With That

By: Charles Blaisdell PhD ChE

Date: April 13, 2022

Where have all the Clouds gone and why care?

The earth’s cloud cover has long been an important puzzle in climate change.  Cloud cover has many types and varies significantly from year to year.  Ground records of global cloud cover over 40 years have shown a 0.41%/decade decrease in cloud cover. (A 37-year European only study found a 1.4%/decade decrease).  In the last 20 years, Dübal and Vahrenholt CERES satellite has data that confirmed the ground observations of cloud cover decrease and a correlation with earth’s net incoming energy flux, albedo, and earth’s temperature rise.  Albedo is derived from the Latin word for white, a high albedo, 1.0, is totally reflective of sun light and a low albedo, 0.0, is totally absorbent, with albedo the lower the hotter.  These few pieces of data beg some questions.   When did cloud cover start to decrease?  Is it cyclic?  How much of the of the observed global warming, GW, can be attributed to cloud cover reduction?  What is causing it?  Will the decrease stop?  And, why should I care?  Let’s start with why should I care, every 1% reduction in cloud cover could account for 1.6 W/m^2 (about 0.8’C) increase in earth’s net incoming energy flux – a significant part of all the observed GW.  If this decrease started a 100 years ago and the current decrease is 0.4%/decade the total decrease over that time could be 2% or 3.2 W/m^2 (estimated 1.6’C GW) – more than the observed 2.2 W/m^2 (1.1’C GW).  Sumerville and Gautier in 1995 summarized that if the cloudiness of the earth decrease it would have a much greater effect on GW than doubling the CO2.  In 1995 no data existed that suggested the cloud cover or relative humidity was changing over time.  That is no longer true. (continue reading)

Where have all the Clouds gone and why care?