Earth's deep blue oceans are fading and changing color — and scientists aren't sure why

• Earth's oceans are getting greener, scientists have found using satellite imagery. 
• More than 56% of the Earth's oceans have changed color over the past 20 years. 
• It's not clear exactly what's driving this, though it's likely linked to the changing climate. 

Earth's deep blue oceans have been fading and changing in color. Scientists aren't exactly sure why, but they think humans are to blame.