{"id":359010,"date":"2024-12-27T10:28:42","date_gmt":"2024-12-27T09:28:42","guid":{"rendered":"https:\/\/climatescience.press\/?p=359010"},"modified":"2024-12-27T10:28:44","modified_gmt":"2024-12-27T09:28:44","slug":"new-study-finds-1970s-present-antarctic-ice-loss-is-unexceptional-and-not-due-to-climate-change","status":"publish","type":"post","link":"https:\/\/climatescience.press\/?p=359010","title":{"rendered":"New Study Finds 1970s-Present Antarctic Ice Loss Is \u2018Unexceptional\u2019 And Not Due To \u2018Climate Change\u2019"},"content":{"rendered":"\n
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From NoTrickZone\u2019<\/a><\/p>\n\n\n\n

By\u00a0Kenneth Richard<\/a><\/em><\/p>\n\n\n\n

Ice shelf collapse was much more pronounced and exceptional millennia ago than it has been over the last 47 years.<\/strong><\/h4>\n\n\n\n

The advent of post-1970s \u201cclimate change\u201d and polar amplification due to the rapidly rising trend in human greenhouse gas emissions was supposed to unleash catastrophic ice calving losses and increases in iceberg size throughout the Earth\u2019s cryosphere.<\/p>\n\n\n\n

But a new analysis (MacKie et al., 2024<\/a><\/strong>) indicates the size of Antarctic icebergs breaking off from the ice sheet has, contrary to popular assumption, slightly declined<\/em> since 1976. Calving events in recent decades therefore cannot even be conclusively attributed to climate change. Instead, they are representative of what occurs naturally.<\/p>\n\n\n\n

\u201c\u2026our results reveal that extreme calving events should not automatically be interpreted as a sign of ice shelf instability, but are instead representative of the natural cycle of calving front advance and retreat.\u201d<\/em><\/p>\n\n\n\n

Over the last 47 years (1976-2023) calving events peaked during the period from 1986 to 2000. Even so, the largest of the modern icebergs calved from Antarctica\u2019s coastal ice shelves were still four times smaller<\/em> than what would occur with an exceptional, once-a-century calving event.<\/p>\n\n\n\n

So even the presumably large calving losses in recent decades that were thought to have been extreme and unparalleled (i.e., the 2017 Larsen C 5,800 km\u00b2 iceberg) could not even reach statistical significance in terms of their exceptionality. It would take and iceberg about 40,000 km\u00b2 in size to be classified as an exceptional, once-a-century calving event.<\/p>\n\n\n\n

\u201c\u2026extreme calving events such as the recent 2017 Larsen C iceberg, A68, are statistically unexceptional and that extreme calving events are not necessarily a consequence of climate change.\u201d<\/em><\/p>\n\n\n\n

Not only has there been no sign of ice shelf instability with the \u201cunexceptional\u201d modern changes, but paleoclimate studies indicate there were periods of ice shelf collapse throughout the Holocene that were much more pronounced than anything occurring in recent decades.<\/p>\n\n\n\n

\u201cNotably, paleoclimate studies suggest that significant ice shelf collapse, on a scale greater than the maximum observed sizes in our data set, has already occurred during the Holocene.\u201d<\/em><\/p>\n\n\n\n

Succinctly, there is nothing even remotely unusual about the calving events occurring across Antarctica today.<\/p>\n\n\n

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Image Source:\u00a0MacKie et al., 2024<\/a><\/strong><\/figcaption><\/figure>\n<\/div>\n\n\n

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