Antarctica is likely warming at almost twice the rate of the rest of the world and faster than climate change models are predicting, with potentially far-reaching implications for global sea level rise, according to a scientific study.
In West Antarctica, a region considered particularly vulnerable to warming with an ice sheet that could push up global sea levels by several metres if it collapsed, the study found warming at twice the rate suggested by climate models.
I donât know about over the last 1,000 years, but over the past four decades Antarctica has been cooling as can be seen in this article by Singh and Polvani.
Low Antarctic continental climate sensitivity due to high ice sheet orography
https://www.nature.com/articles/s41612-020-00143-w
DB2
Except for maybe those red sections on the chart you post. If the red sections have some melting and/or breaking off of ice, in the past and/or next few years and the blue sections stay frozen, letâs suppose, then still on average Antarctica could be melting.
Also, Antarctica is only one portion of the planetâs water. The earth is full of water that is available to absorb heat trapped by greenhouse gases and no one expects these different areas across the globe to respond in a homogeneous way to warming: some areas will warm more or less than others. Perhaps Antarctica is one area that, for now, is warming less maybe in part due to reasons noted in the article cited here. But that makes me concerned about the rest of the worldâs water and the portions that are warming faster.
Many smaller ice cubes melt faster than fewer larger cubes having the same basic shape and same total mass. This makes me concerned that as polar ice melts and fragments, its rate of future melting will accelerate. This means we cannot simply linearly extrapolate past melting to forecast future melting. A less fun future will be upon us faster, leaving less time to agree on how to respond with policy - we are possibly seeing this happen with property insurance ($ at risk will crystallize oneâs view of the data, it seems).
Bob,
It is till it isnât.
Meaning the slight warming of the earth over the next hundred years will make their research look stupid.
When the Vikings found Iceland and then North America they set up settlements. The temperature of the North Atlantic dropped by one degree and those settlements were lost as the ocean froze over. The risks involved going forward for Antarctica are huge. What is happening in the west of the continent will spread and get worse.
Hereâs what science has to say about it.
Well written appraisal of what is happening.
To my point
Unfortunately, adding more greenhouse gases to the atmosphere wonât strengthen Antarcticaâs negative greenhouse effect, Sejas says. A warming world will, in fact, boost the amount of water vapor in the stratosphere globally, eventually rendering the continent as susceptible to greenhouse warming as the rest of the planet.
Which make up only a few percent of the continent. However, it seems the Antarctic Peninsula has also been cooling for the last couple of decades.
Recent regional climate cooling on the Antarctic Peninsula and associated impacts on the cryosphere
Oliva et al.
⢠We examine climate variability since the 1950s in the Antarctic Peninsula region.
⢠This region is often cited among those with the fastest warming rates on Earth.
⢠A re-assessment of climate data shows a cooling trend initiated around 1998/1999.
⢠This recent cooling has already impacted the cryosphere in the northern AP.
⢠Observed changes on glacial mass balances, snow cover and permafrost state.
Absence of 21st century warming on Antarctic Peninsula consistent with natural variability
Turner et al.
https://www.nature.com/articles/nature18645
DB2
I donât think âa few percentâ can be dismissed. In the same way I wouldnât dismiss these few percent:
âThese cancers make up only a few percent of your pancreas.â
âThese fire hotspots make up only a few percent of the grassland.â
Actually, while temperature is obviously relevant, I can think of other measures that I find more directly relevant to making an aggregate, high-level measure of global warming. As one example related to the Antarctic region, I am more interested in the water balance in mass terms across the globe. Specifically, how much mass of water is in ice (e.g., our polar ice) and liquid (our oceans) and also how much mass is transitioning between the two states over some time interval?
For example,
New IMBIE assessment published in Earth System Science Data (20/04/2023):
âThis new assessment of ice sheet mass balance shows that Melting of the polar ice sheets has caused a 21 mm rise in global sea level since 1992, almost two thirds (13.5 mm) of which is due to Greenland and one third (7.4 mm) to Antarctica. In the early 1990s, ice sheet melting accounted for only a small fraction (5.6 %) of sea level rise. However, there has been a fivefold increase in melting since then, and they are now responsible for more than a quarter (25.6 %) of all sea level rise.â
(imbie.org)
âOverall, the long-term trend in Antarctic sea ice is nearly flat. (in contrast, the glaciers and ice sheets over land in Antarctica are losing mass.)â
(Understanding climate: Antarctic sea ice extent | NOAA Climate.gov)
