Topic: Space

Scientists at The Hong Kong Polytechnic University have created a precise record of ocean mass changes over 30 years. They used space lasers and found that the oceans are rising faster than ever, mainly due to melting land ice.

The Earth's oceans are getting bigger. This is one of the clearest signs of climate change. Researchers at The Hong Kong Polytechnic University have created a precise record of ocean mass changes over 30 years. They used space lasers and found that the oceans are rising faster than ever, mainly due to melting land ice.

The team led by Prof. Jianli Chen and Dr. Yufeng Nie developed a new method to track long-term changes in ocean mass. This is important for understanding why sea levels are rising today. They used satellite laser ranging (SLR) data collected between 1993 and 2022.

Their findings show that the oceans have risen by about 90 mm over this period. Roughly 60% of this increase was caused by the growing mass of the oceans. Since around 2005, rising ocean mass has been the main factor driving higher sea levels.

The primary source of this added water is accelerated melting of land ice, especially from Greenland. Over the full study period, melting from polar ice sheets and mountain glaciers contributed more than 80% of the total increase in global ocean mass.

Why It Matters

This research matters to Indian students because it shows how climate change is affecting our planet's oceans. As sea levels rise, coastal cities like Mumbai and Chennai are at risk of flooding. Understanding these changes can help us prepare for the future and take action to reduce our carbon footprint.

Key Facts

• The oceans have risen by about 90 mm over a 30-year period (1993-2022).
• Roughly 60% of this increase was caused by the growing mass of the oceans.
• Since around 2005, rising ocean mass has been the main factor driving higher sea levels.
• The primary source of this added water is accelerated melting of land ice, especially from Greenland.
• Over the full study period, melting from polar ice sheets and mountain glaciers contributed more than 80% of the total increase in global ocean mass.

Key Terms

Barystatic sea level

The change in the amount of water in the oceans, not just the height

Implications

This research matters to Indian students because it shows how climate change is affecting our planet's oceans. As sea levels rise, coastal cities like Mumbai and Chennai are at risk of flooding. Understanding these changes can help us prepare for the future and take action to reduce our carbon footprint.