Residents in New Orleans, the Florida Keys, and other coastal areas around the country may have a vested interest in Antarctic octopus love stories from about 125,000 years ago.
That's because the plotline — perhaps fodder for a steamy romance novel (of the eight-limb variety) — could mean hot water for the rest of us. If the past repeats itself, experts fear that sea levels could rise dangerously. The findings also solve a mystery for the team about how warming impacts ice sheets.
What's happening?
Scientists studying octopus DNA have found evidence that breeding between previously separated groups of the species was made possible when ice sheets melted in Earth's distant past, per research from Australia's James Cook University.
The creatures waited hundreds of thousands, even millions of years, for pathways to melt open in the West Antarctic Ice Sheet (WAIS) between the Weddell, Amundsen, and Ross Seas, which allowed interbreeding. The interest for romance readers may end there.
That's because the planet's temperature when the ice sheets collapsed back then is close to current levels, according to a university release. If the ice shrinks again, the consequences could be far-reaching, especially if sea levels rise, according to a Phys.org story on the research.
Scientists are confident that octopus genetic mixing has happened during two arctic meltdowns long ago. The first was between 3 million and 3.5 million years ago. The second, most recent incident is a warmup around 116,000 to 129,000 years ago, per Phys.org.
Professor Jan Strugnell, one of the study's lead authors, said that global temperatures may have reached up to 2.7 degrees Fahrenheit "warmer than pre-industrial levels" during that melting. Global sea levels, she said, were 16.4 to 32.8 feet "higher than today," all per the university.
Why is it important?
To avoid worst-case environmental scenarios, climate experts warn that the global average temperature can't exceed pre-industrial times (1850-1900) by 2.7 degrees Fahrenheit.
Unfortunately, the global average surface temperature has already increased by about 2 degrees Fahrenheit since that time, according to Climate.gov.
"What makes the WAIS important is that it's also Antarctica's current biggest contributor to global sea level rise. A complete collapse could raise global sea levels by somewhere between 3 and 5 meters [about 9.9-16.4 feet]," Strugnell said in the report.
NASA has a map of areas around the planet that will likely be impacted by sea level rise during the next 100 years. The coasts of most continents, including North America, are marked.
"Rising sea levels in the 3- to 6.5-foot range will cause widespread damage to coastal areas," per NASA.
Researchers from other universities, commenting on the study, noted in Phys.org's story that other factors might also be impacting ice melt, including ocean current changes. But the "latest piece of evidence from octopus DNA stacks one more card on an already unstable house of cards," they wrote, per Phys.org.
How to help
We can help to reduce planet-warming air pollution — and even save some money — by buying reusable products and recycling.
Consider an electric vehicle the next time you buy a car, and never pay for gas again. Simple decisions around the house, like unplugging energy vampires, can save you $165 a year. Better yet, it's a move that can help to reduce the amount of ice-melting air pollution we create.
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