Claim that melting ice caps don't contribute to the rising sea levels is false

By: Rajeswari Parasa
May 6 2024

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Screenshot of the claim circulating on social media platform (Source:TikTok/Modified By Logically Facts)

What is the claim?

A TikTok video (archived here) of a man conducting an experiment of ice melting in a glass of water to claim that melting ice caps do not contribute to rising sea levels is gaining a lot of traction online. The video features a man speaking in Swedish, with a purported news article in Swedish about melting ice caps floating in the background, followed by another video in the background where one can see ice in a glass of water slowly melting.

The man in the video says in Swedish,  "Everyone's heard about global warming and that the biggest topic around global warming is that the Arctic is melting, which is elevating sea levels globally. But is that really the case?" He adds that he conducted an experiment where he filled a glass of water and, topped it with ice, and let it melt. "What do you think will happen? Do you think the ice will melt and that the water will spill out of the glass? Logically speaking, it should spill over because that's what they say, the polar ice is melting and causing the sea levels to rise (sic)." He then says that 45 minutes later, "all ice had melted, but there was exactly the same amount in the glass. And why is that? It's about two things; mass and volume. You've been fooled when it comes to global warming (sic)."

Screenshot of claim made online. (Source: TikTok)

However, the parallels drawn in the video are misleading, and the claim that melting ice caps do not lead to rising sea levels is not true.

What do experts say?

Logically Facts contacted several experts to understand the phenomenon of melting ice caps and its potential impact on rising sea levels. According to experts, melting ice caps on land contribute to rising sea levels, unlike the melting of ice already floating in the ocean. While ice that is formed in the oceans does not increase sea levels, the concern here is when ice from the land melts and adds to the ice present in the oceans.

Neil Arnold, the Director of Scott Polar Research Institute, who focuses on glacier hydrology at the University of Cambridge, said, "Melting an iceberg in itself does not raise sea level. The critical aspect is actually putting the ice in the sea in the first place. An ice cap or glacier on land can melt more, so there is more river runoff, which eventually enters the sea in larger quantities due to the higher ice melt. This will raise sea levels."

Arnold further explained, "If we go back to thinking about an iceberg in the ocean, the critical idea is actually how many icebergs are added to the sea over a period of time — say in a year. If that number increases, sea levels will rise because of that alone — it does not matter if they melt or not once they are in the sea. Climate change leads to more iceberg production, especially from Greenland and Antarctica."

Bill McGuire, a geophysical and climate hazards professor at University College, London (UCL), provided clearer examples indicating that ice takes up more volume than water. He said, "Ice cubes in a glass are floating in the water. Ice has a greater volume than a comparable weight of water so the level of water will fall as the ice melts. Floating ice shelves do the same. However, the Greenland and Antarctic ice sheets are mainly grounded on land."

McGuire added that every scrap of ice that melts on land is added to the volume of the oceans, driving up sea levels, which are now climbing at about 0.5cm a year. This contradicts the claim being made in the TikTok video. 

Rise in sea levels 

Data has shown the global mean sea levels have risen by 10.1 centimeters from 1992 to 2022 alone. Studies show most of it is because of two factors: one, the melting of ice sheets and glaciers, and the other, the expansion of seawater. 

An experiment suggested by NASA (National Aeronautics and Space Administration) shows how sea levels rise, which also debunks the claim being made in the now-viral video. Here, the organization tried to demonstrate the difference between the impact of ice melting, both on land and on water. As a part of this experiment, two identical tubs, A and B, were taken, and two equal amounts of clay were placed in both, representing land. Ice cubes were then placed on the clay in tub A along with water. In tub B, water was poured over ice cubes and placed in the tray till it reached the level of the clay. Through this experiment, one could understand how more water is being added to Earth's oceans when glaciers on land melt.

The verdict

The claim that melting ice caps do not lead to a rise in sea levels is false. The experiment cited in the video — showing that the water level in a glass of water does not increase after the ice in the glass melts — has been wrongly juxtaposed to downplay the effects of global warming. Experts say melting ice caps on land entering the oceans can increase sea levels and does contribute to climate change. Hence, we have marked this claim as misleading.