"Earth is getting darker"

Here's the latest "must read" by James Hansen.

Key takeaways:

• Earth's albedo (reflectivity) has declined over the past 25 years, according to precise satellite data.
• This decline is primarily attributed to reduced reflection of sunlight by clouds.
• While reduced human-made aerosols contribute to some cloud change, most of it is due to cloud feedback related to global warming.
• The observed albedo change indicates that clouds provide a large, amplifying climate feedback.
• This large cloud feedback supports the conclusion of high climate sensitivity.

Read Hansen's full article: