In east Antarctica, the sea ice sheets have been larger recently. Predictably this has been seized on by the scientifically simple-minded climate change deniers (CCD’s) as evidence that climate change models are incorrect. This is despite it being predicted very closely by the same climate models well before it happened. I remember it being pointed out as a counter-intuitive effect in the 1990’s (no link I’m afraid) of global warming. Hypothesis, prediction and confirmation are the essence of the scientific process. Finding a predicted effect happening tends to confirm an hypothesis rather than refute it.
Increasing greenhouse gases cause climate change, but not always climatic warming in particular areas. As the climate patterns change, some areas will get a lot colder as the overall world climate heats up. It all depends on that the weather patterns and ocean currents do in response to the changes in heat balance shifts. The heating and desertification of the tropics during temperate latitude glaciations is a similar counter-intuitive effect of weather pattern changes.
Why does increasing Antarctic sea ice not challenge current scientific thinking about global warming? I’ll defer to the US agency the National Snow and Ice Data Center
“Another important point is that the increase in Antarctic sea ice extent is not surprising to climate scientists. When scientists refer to global warming, they don’t mean warming will occur everywhere on the planet at the same rate. In some places, temporary cooling may even occur. Antarctica is an example of regional cooling. Even our earliest climate models projected that Antarctica would be much slower in responding to rising greenhouse gas concentrations than the Arctic. In large part, this reflects the nature of the ocean structure in Antarctica, in which water warmed at the surface quickly mixes downward, making it harder to melt ice.
In terms of sea ice, climate model projections of Antarctic sea ice extent are in reasonable agreement with the observations to date. It also appears that atmospheric greenhouse gases, as well as the loss of ozone, have acted to increase the winds around Antarctica. Perhaps counter intuitively, this has further protected the Antarctic from warming and has fostered more ice growth.
The one region of Antarctica that is strongly warming is the Antarctic Peninsula, which juts out into the Atlantic Ocean and is thus less protected by the altered wind pattern. The Antarctic Peninsula is experiencing ice shelf collapse and strongly reduced sea ice.”
Adding Noughts goes on to explain that the east Antarctica sea ice sheets aren’t that important in sea level calculations because they routinely break up in summer anyway and float away. They’d be of interest for climate change model if they remained in place over summer because that would constrain the flow of ice from the ice streams on land behind them.
The opposite effect has shown in the west Antarctica Peninsula ice sheets where the disintegration of relatively permanent ice shelfs have produced an increase in the speed of the ice-streams behind them. After the final breakup of the Larsen B sea ice sheet in 2002, there was a marked increase in the flow of the ice streams in that area (as had previously been observed in 1995 final breakup of the Larsen A sea ice shelf). This has resulted in considerable mass wasting across the ice streams on the Antarctica Peninsula as each of the sea shelf disintegrated.
There is a very good discussion of ice shelf disintegration at the NSIDC. The one to watch is the Ross ice shelf which is the exit point for the West Antarctica Ice Sheet (WAIS), which is fortunately still inside the stronger weather pattern around Antarctica.
The Ross Ice Shelf is the main outlet for several major glaciers from the West Antarctic Ice Sheet. This single ice sheet contains enough above-sea-level ice to raise global sea level by 5 meters. At present, the Ross Ice Shelf’s mean annual temperature is well below freezing. Although summer temperatures in the warmest part of this shelf are currently just a few degrees too cool for the formation of melt ponds, there is no evidence of a strong warming trend on the Ross Ice Shelf at this time.
If summer temperatures start to rise in this area as has happened over decades in the Antarctica Peninsula, we’re likely to get the same kind of breakups. Apart from the immediate drowning effect, there is a real risk that it would increase the speed of the WAIS.
The West Antarctic Ice Sheet(WAIS) is a unique marine ice sheet, anchored to bedrock, and in places it dips thousands of metres below sea level with margins that are floating. Other marine ice sheets existed in the Northern Hemisphere during the last glacial maximum but all disintegrated and melted away during the current warm period. The West Antarctic Ice Sheet is the only marine ice sheet remaining from the last glacial period.
The resulting mass-wasting of the WAIS after the Ross ice shelf disintegrated (as has been seen in the Antarctica Peninsula) would then start to cause some serious sea level rises. What has been shown is that once one of these shelves breaks up, everything happens rapidly.
Now to stop being so rational and enter the same space as the idiotic writings of some CCD’s. Fortunately for the BustedBlonde, her liver should have given out from gin poisoning within the decade long before any of this happens. Probably no real loss, as her brain looks like it is long gone already from her limited understanding and shallow pronouncements on climate change. If she isn’t getting the DT’s on schedule, she should get a lot more water in her gin over the next couple of decades because some of these effects look like they’re starting to feedback on each other.