Recent climate research highlights a critical factor in global sea-level rise: melting land ice. A study published in the Proceedings of the National Academy of Sciences reveals that space-based tools, including satellite laser ranging (SLR), can now measure ocean mass with incredible accuracy.
Traditionally, sea-level rise was largely attributed to the warming of ocean water—this is called thermal expansion. While that’s still important, new findings show that melting ice is becoming a bigger issue. The study claims that most of the water contributing to rising seas comes from ice loss, especially in Greenland and glaciers worldwide. Lead researcher Prof. Jianli Chen stated, “In recent decades, climate warming has led to accelerated land ice loss, which is increasingly driving global sea-level rise.”
Over the past 30 years, global sea levels have risen about 90 millimeters. Alarmingly, approximately 60% of this rise is due to the added mass of water from melting ice, rather than just water expanding as it heats. This swelling ocean contributes to more frequent coastal flooding and threatens ecosystems.
SLR represents a leap forward in measuring ocean mass. By using laser beams between satellites and ground stations, researchers can detect subtle changes in the Earth’s gravity. This offers a direct measure of how much ocean mass changes, a significant advancement over older methods that primarily assessed ocean surface height without considering mass. Dr. Yufeng Nie, another author of the study, noted the remarkable correlation between the ocean mass data from SLR and overall sea level changes measured by satellite altimeters.
The results of this research are crucial for improving climate models. Prof. Chen emphasized that the study allows for a direct assessment of ocean mass increase and its long-term implications for sea-level budgets. As temperatures rise, further loss of land ice in polar regions could accelerate sea-level increases, highlighting the urgent need for action against climate change.
Long-term, precise data is essential for understanding climate change. Advanced technologies like SLR and satellite altimetry provide valuable insights into shifts over decades. Without such data, predicting future climate trends and formulating effective policies becomes challenging.
This study serves as a reminder that the effects of rising sea levels aren’t just future problems; they are already affecting coastal cities and low-lying nations. The flooding issues these areas face are growing, underscoring the need for effective responses to protect vulnerable communities and ecosystems. Understanding these changes is crucial for everyone as we navigate the implications of climate change.
For more details, visit the Proceedings of the National Academy of Sciences.
