{"id":472482,"date":"2026-09-20T07:40:28","date_gmt":"2026-09-20T14:40:28","guid":{"rendered":"https:\/\/climatescience.press\/?p=472482"},"modified":"2026-09-20T07:40:30","modified_gmt":"2026-09-20T14:40:30","slug":"satellites-reveal-greenland-and-antarctica-lost-over-11-trillion-tons-of-ice-since-the-1970s-84-driven-by-speeding-glaciers","status":"publish","type":"post","link":"https:\/\/climatescience.press\/?p=472482","title":{"rendered":"Satellites Reveal: Greenland and Antarctica Lost Over 11 Trillion Tons of Ice Since the 1970s \u2014 84% Driven by Speeding Glaciers"},"content":{"rendered":"\n
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AI generated by Grok<\/figcaption><\/figure>\n\n\n\n

Satellites show Earth lost more than 12 trillion tons of ice from Greenland and Antarctica over ~47 years (roughly 1979- 2023), according to a major study published in Scientific Data.<\/strong><\/p>\n\n\n\n

Key findings from the international collaboration (led in part by the European Space Agency\u2019s IMBIE<\/strong> initiative, incorporating NASA satellite data <\/strong>for a longer record):<\/p>\n\n\n\n

Total ice loss:<\/strong> about 12.5 trillion tons (11.3 trillion metric tons). This is enough to cover the continental United States with ice roughly 5 feet (1.5 meters) deep.<\/p>\n\n\n\n

Sea- level contribution:<\/strong> This melt alone raised global sea levels by about 1 inch (\u22483.1 cm) since 1979 (on top of other factors). Greenland accounts for a somewhat larger share.<\/p>\n\n\n\n

Main driver:<\/strong> ~5\/6 (about 84%) of the loss comes from dynamic processes<\/strong>, warmer ocean water undercutting and melting ice sheets from below\/sides, accelerating glacier flow into the ocean, rather than surface melting from warmer air.<\/p>\n\n\n\n

Acceleration: <\/strong>Ice sheets were relatively stable<\/strong> in the 1970s-1990s<\/strong>; losses ramped up later, especially in the 2010s. A temporary slowdown<\/strong> around 2020- 2023<\/strong> (partly due to heavy snowfall in East Antarctica<\/strong> offsetting West Antarctic losses) was viewed as short- term variability; the longer- term accelerating trend has resumed.<\/p>\n\n\n\n

Methods:<\/strong> Combined data from dozens of independent surveys and 27 satellites<\/strong> (including earlier Landsat archives) for the longest continuous satellite- based mass- balance record<\/strong> of the two ice sheets.<\/p>\n\n\n\n

Scientists involved (including Ines Otosaka of Northumbria University and Eric Rignot of UC Irvine) emphasize that the dynamical ice discharge raises concerns about potential tipping points or instability<\/strong>, particularly in parts of Antarctica<\/strong>, with implications for continued sea- level rise and coastal flooding risk even if warming stabilizes. Independent experts noted the multi- method approach increases confidence in the upward trend.<\/p>\n\n\n\n

The article is an Associated Press report by Seth Borenstein (dated around mid- to- late September 2026 in various outlets).<\/p>\n\n\n\n

This extends earlier satellite records (previously focused more on the 1990s onward) and aligns with the broader observed pattern of accelerating polar ice loss linked to climate change.<\/p>\n\n\n\n

_____________________________________________________________________________________<\/p>\n\n\n\n

SMB models refer to Surface Mass Balance models<\/strong> (or, more precisely, the surface mass balance components derived from regional climate models).<\/p>\n\n\n\n

In the context of the Greenland and Antarctic ice- sheet mass- balance study we discussed:<\/p>\n\n\n\n

What is Surface Mass Balance (SMB)?<\/strong><\/p>\n\n\n\n

SMB is the net gain or loss of mass at the surface of an ice sheet. It is calculated as:<\/p>\n\n\n\n

SMB<\/mtext>=<\/mo>snowfall accumulation<\/mtext>\u2212<\/mo>(<\/mo>meltwater runoff<\/mtext>+<\/mo>sublimation<\/mtext>+<\/mo>evaporation<\/mtext>+<\/mo>blowing-snow erosion<\/mtext>)<\/mo><\/mrow>\\text{SMB} = \\text{snowfall accumulation} – (\\text{meltwater runoff} + \\text{sublimation} + \\text{evaporation} + \\text{blowing-snow erosion})<\/annotation><\/semantics><\/math><\/p>\n\n\n\n

Positive SMB means the ice sheet is gaining mass at the surface (mainly from snowfall). Negative SMB means net surface loss (mainly from melting and runoff).<\/p>\n\n\n\n

Role of SMB models in the study<\/strong><\/p>\n\n\n\n

The paper uses regional climate models (RCMs) <\/strong>to estimate SMB. These models simulate the atmosphere\u2013 ice- sheet interactions at relatively high spatial resolution over the polar regions. Common examples used in ice- sheet research include:<\/p>\n\n\n\n