The Earth has gained coastal land equivalent to the size of Jamaica in the past 30 years with man-made construction outpacing erosion caused by rising sea levels, mapping data showed on Thursday.

Expansion of ports off China, construction of luxury resorts off Dubai and land reclamation in the Netherlands were among causes of coastal expansion, according to a study by Dutch research group Deltares.

Using satellite data with Google Earth, Deltares said coastal regions had gained a net 13,565 sq. km of land since 1985, roughly the size of Jamaica or the U.S. state of Connecticut.