‘Cruisezilla’ passenger ships have doubled in size since 2000, campaigners warn

Experts say booming demand for holidays afloat mean ocean liners' burden on the environment is growing

The huge passenger vessels sometimes known as cruisezillas" are getting bigger than ever, according to new research which has found that the world's biggest cruise ships have doubled in size since 2000.

If the industry's growth does not slow, the biggest ships in 2050 will be eight times larger, in terms of tonnage, than the Titanic - the largest ship on the seas before it sank a century ago, according to the campaign group Transport & Environment (T&E). The group also found that the number of cruise ships has risen 20-fold since 1970.