Present-Day Sea Level Rise and Causes: The Role of Space Observations

ABSTRACT For several decades, sea level has been rising at an accelerated rate. This is what altimeter satellites that have routinely monitored sea level and its evolution for more than three decades, show. Thanks to different independent observation systems, the causes of the global mean sea level rise are now well quantified. These include the warming of the ocean, which is expanding and the melting of land ice, two phenomena induced by the current global warming caused by fossil fuel combustion. Projections from climate simulations indicate that the sea level will continue to rise over the next decades, or even centuries, at a speed that will depend on future greenhouse gas emissions. In this review, we present the most up-to-date results about space-based sea level observations from global to local scales. We also discuss the causes of sea level changes and briefly address possible trajectories of future sea level rise.