Britain is accelerating plans to protect London from flooding caused by a warming climate and rising sea levels, bringing forward its scheme to protect the city center by 15 years.

London, which sits on a tidal stretch of the River Thames about 80 kilometers from the sea, is protected from storm surges by a 520-meter-wide movable flood barrier east of the city that is raised a handful of times each year.

The government said in a statement it was speeding up an existing climate adaptation program, bringing forward a target to raise defenses in the city to 2050, rather than by 2065 as originally set out in a 2012 document.

“Sea levels are rising at an accelerated rate across the Thames Estuary, and it is therefore essential that we act now to respond to the changing climate,” said Julie Foley, an official at the Environment Agency public body that developed the plans.

The government statement said the change was based on improved climate change models that showed the “heightened risk of flooding from a warming climate and rising sea levels.”

Rising sea levels, in part caused by melting glaciers and record ocean temperatures, are a global threat posing existential risk to some low-lying island states and coastal cities.

In April, the World Meteorological Organization said global sea levels were rising at more than double the pace they did in the first decade of measurements in 1993-2002 and touched a new record high last year.

The full revised plan from Britain will be published Wednesday, setting out how authorities plan to protect 1.4 million people and $405 billion in property from existing tidal risks and new ones driven by climate change.

The 2012 plan had said defenses in the section of the river running past London landmarks such as the Houses of Parliament and the Tower of London would need to eventually be raised by up to a meter.