How accurate is accurate enough for measuring sea-level rise and variability

Abstract

Sea-level measurements from radar satellite altimetry have reached a high level of accuracy and precision, which enables detection of global mean sea-level rise and attribution of most of the rate of rise to greenhouse gas emissions. This achievement is far beyond the original objectives of satellite altimetry missions. However, recent research shows that there is still room for improving the performance of satellite altimetry. Reduced uncertainties would enable regionalization of the detection and attribution of the anthropogenic signal in sea-level rise and provide new observational constraints on the water–energy cycle response to greenhouse gas emissions by improving the estimate of the ocean heat uptake and the Earth energy imbalance. Satellite radar altimetry enables the detection of sea-level changes by collecting data that have exceeded early expectations. This Perspective discusses potential advances that would enhance the data, allowing regional detection and attribution of sea-level change and improving ocean heat uptake estimates.