Antarctic ice sheets may be more stable than previously thought

The main ice shelves in Antarctica seem to have survived the hot period more than 120, 00 years ago. This indicates that the Westwest Pole ice sheet is not as vulnerable as it is thought to complete the complete collapse caused by climate change. You can raise the sea surface by one meter. However, great uncertainty remains.

“It's good news and bad news.” Eric Wolf At Cambridge University in the UK. “There was no worst scenario, but I can't say that it won't happen in the next century or the second century.”

The climate change caused by humans uncertains the future of the Ice bed in the Southwest Pole. If you continue to release high -level greenhouse gases, some models will completely disappear the ice sheet over the next few centuries. The most extreme scenarios projected by the inter -government panel on climate change in 2023 can lead to up to 2 meters up to the sea level by 2100.

Wolf and his colleagues looked at Ronne's ice shelves, a large part of the ice sheet that extends to the sea, to see how they behaved from 117, 00 to 126 to 00 years. Meanwhile, it was part of the last inter -glacier, and the change in the orbital of the earth increased the temperature of the Antarctica even higher than today.

In order to judge the range of Ronne's ice shelves during the warm period, researchers measured the concentration of the sea salt of the ice core about 650 km away from the end of the shelf. When the ice shelf melted between the last glacier, the edge was approaching the core. As a result, the researchers expected that the core was much closer to the ocean, so the core salt concentration would rise 8 times. “It would have been a seaside resort,” Wolf says.

Instead, they discover that the salt concentration between the last glacier is similar to today's concentration or even lower, indicating that the edge of the ice sheet remains far. Other measurements of the coat of water in the core, which maintain evidence of weather patterns affected by the change in the ice sheet, suggest that Ronne's ice shelves lasted during the last ice age.

Wolfff suggests that ice stability in the previous warm period is unlikely that climate change will be completely collapsed as the climate change increases the global temperature. However, he and other researchers say that the rise of the sea surface due to melting of ice is still a big risk.

“That means that there was no complete removal cation in the South Pole, but we do not provide enough information to relax.” Timothy Naish At Werrington Victoria University in New Zealand.

One is that the survival of Ronnes Ice Shelf does not mean that other ice areas such as Swaites and Pine Island have not melt. In fact, Wolf says the record of the core's water level suggests what they did. The ice score used by the researcher did not cover the warmth of the last ice age.

The dynamics of glacial warming between glaciers, which change in the region, are different from today's global warming, where the temperature is rising throughout the planet. For example, Wolf says that warm seawater that reaches Antarctica can accelerate melting by invading under ice.

“This is a really important observation, but I think it will take more time to understand what it means.” Andrea Duton At Wisconsin University Madison School. She emphasizes that researchers are spending 50 years and trying to think about what happened in the Westwest Pole in the last ice age.