Sea level rise is increasing fastest in populous coastal areas, study says

This aerial picture shows people rowing a raft over a flooded road in Jakarta on February 20, 2021, following heavy overnight rains. The combination of so many people and the multitude of rivers has made this city especially prone to relative sea level rise.

(CNN)Coastal communities are experiencing sea level rise four times worse than global water rise, according to a new study released Monday.

Groundwater pumping, extraction of materials from the ground and sediment production are all happening near the coasts and that is causing the land to actually sink -- compounding the effects of a rising sea level.
It is no coincidence that these are the same locations where people live, worsening the impacts and increasing the vulnerability.
    Many of the largest, most populated cities in the world are built along the deltas of major rivers, where there is the added exposure of rivers connecting to the ocean.
      Much of the coast is uninhabited by people, but where there is civilization, there tends to be a greater rise in water levels.
      According to the study, it quantifies "global-mean relative sea-level rise to be 2.5 mm per year over the past two decades. However, as coastal inhabitants are preferentially located in subsiding locations, they experience an average relative sea-level rise up to four times faster at 7.8 to 9.9 mm per year."

      Coastal lands are sinking

      This is the first ever study that factors in land subsidence into current sea level rise observations globally.
      "We've actually quantified (sea level rise) and are able to get the relative magnitude. And it's surprising -- it's surprisingly large. We're making the point that climate change is bad and climate induced sea level rise is bad," Robert Nicholls, lead author of this research and director of the UK's Tyndall Centre for Climate Change Research, told CNN.
      "But we have this additional process that is making things even worse. And of course, these things add up. It doesn't really matter whether the sea rises or the land sinks, the people living on the coast still have the sa