The claim: Measuring cup meme proves ice melt from global warming can't cause sea-level rise
Since 1993, average global sea levels have risen roughly four inches due to global climate change, according to NASA. However, a meme that suggests polar ice melt from climate change cannot cause sea-level rise has resurfaced on social media.
The meme shows two images side by side.
One image shows a measuring cup with water and ice in it. The ice is labeled "ice berg." The water is labeled "ocean."
The other image shows a measuring cup with water and no ice, with water at a similar level. The image is labeled "ice berg melts" (pointing to where the ice was in the other image) and "ocean level remains the same."
"A little science lesson for the #IDIOTS at the global warming conference," reads the meme text in a June 5 Facebook post.
However, the meme is misleading and the claim it makes is false. It depicts a situation where the melting of ice that was already floating in the container failed to significantly change the water level. That's not what happens in the oceans.
Sea-level rise occurs when water from melting land-based ice sheets and glaciers pours into the ocean. This adds more water to the ocean than it previously contained, which raises sea levels.
Sea-level rise is also exacerbated by global warming itself because water expands as it heats up.
Neither of these processes – the loss of land-based ice or the thermal expansion of ocean water – is represented in the meme.
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USA TODAY reached out to the social media users who shared the claim for comment.
Meme does not demonstrate processes that cause sea-level rise
The experiment depicted in the meme fails to demonstrate the processes that cause sea-level rise, according to Claire Parkinson, a NASA climatologist.
"It instead is showing something that doesn’t cause sea level rise – the melting of ice that was already floating in the ocean," such as sea ice, Parkinson told USA TODAY in an email.
Arctic sea ice – seawater that freezes and then floats on the ocean – is being lost to climate change, but the meltwater does not directly contribute to sea-level rise since it originated in the ocean.
"The main causes of sea-level rise is by the addition of land-based ice into the sea and the natural expansion of the ocean with warming," Sally Brown, a sea-level rise researcher and deputy head of the Department of Life and Environmental Sciences at Bournemouth University, told USA TODAY in an email.
The other major contributor to sea-level rise, ocean expansion due to global warming, is "responsible for one-third to one-half of global sea-level rise," according to the NASA website.
Parkinson said the experiment depicted in the meme would have to be altered to accurately simulate the processes that contribute to sea-level rise.
"This could be done by either adding water or ice to the cup – simulating the addition of (glacial) meltwater," she said. It could also be accomplished by "heating the water so much that its expansion" raises the water level in the cup.
The meme was previously debunked by Reuters.
Our rating: False
Based on our research, we rate FALSE the claim that a measuring cup meme proves ice melt from global warming can't cause sea level-rise. The experiment depicted in the meme does not simulate the processes that actually contribute to global sea-level rise – ocean expansion and the melting of land-based ice masses.
Our fact-check sources:
Sally Brown, June 15, Email exchange with USA TODAY
Claire Parkinson, June 15, Email exchange with USA TODAY
National Snow & Ice Data Center, Oct. 27, 2020, What are the impacts of Arctic sea ice loss?
NASA Vital Signs of the Planet, accessed June 15, Sea level
NASA Vital Signs of the Planet, accessed June 15, Arctic sea ice extent
NASA Vital Signs of the Planet, accessed June 15, Ice sheets
Carbon Brief, April 28, 2021, Melting glaciers drove ‘21% of sea level rise’ over past two decades
NASA Vital Signs of the Planet, accessed June 15, Ocean heat content
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This article originally appeared on USA TODAY: Fact check: Measuring cup meme misrepresents causes of sea-level rise