Global warming is happening for real. Climate is changing and sea levels are rising.

Recently, a massive cavity two-thirds the size of Manhattan has been discovered in an Antarctic glacier.

Thwaites Glacier is currently responsible for approximately 4% of global sea level rise. 

Source: Newsweek

In a statement, NASA's Jet Propulsion Laboratory stated:

"The huge hole measuring almost 1,000 feet (300 meters) tall, was found growing at an 'explosive rate' at the bottom of a glacier in West Antarctica."
Source: The Conversation

The researchers had expected to find some gaps between ice and bedrock, however, they were shocked to see the size and growth of the newfound hole. 

The hole is big enough to have contained 14 billion tons of ice, and most of that ice melted over the last three years.

Source: abwnet

If this melting of glaciers continues, the world would witness a great rise in sea levels.