The rise in global mean sea level (GMSL) is a critical indicator of climate change. Hong Kong Polytechnic University (PolyU) researchers have utilized advanced space geodetic technologies to deliver the first precise 30-year (1993–2022) record of global ocean mass change (also known as barystatic sea level), revealing its dominant role in driving GMSL rise.
The rise in global mean sea level (GMSL) is a critical indicator of climate change. Hong Kong Polytechnic University (PolyU) researchers have utilized advanced space geodetic technologies to deliver the first precise 30-year (1993–2022) record of global ocean mass change (also known as barystatic sea level), revealing its dominant role in driving GMSL rise.
Their research further indicates that GMSL has been increasing at an average rate of approximately 3.3 mm per year with a notable acceleration observed, highlighting the growing severity of climate change. The findings have been published in the Proceedings of the National Academy of Sciences.
GMSL is primarily driven by two factors: the thermal expansion of seawater—as the oceans absorb around 90% of the excess heat in the Earth’s climate system—and the increase in global ocean mass, which is mainly caused by the influx of freshwater from melting land ice. Therefore, long-term monitoring of global ocean mass change is essential for understanding present-day GMSL rise.
A research team led by Prof. Jianli Chen, Chair Professor of Space Geodesy and Earth Sciences of the PolyU Department of Land Surveying and Geo-Informatics (LSGI) and a core member of the PolyU Research Institute for Land and Space, together with Dr.
