My 3000th post!
Of course, Arctic ice has been shrinking since at least 1980, with both seasonal maxima and seasonal minima getting lower in volume every year:
![[Image: 220px-Plot_arctic_sea_ice_volume.svg.png]](https://upload.wikimedia.org/wikipedia/commons/thumb/5/51/Plot_arctic_sea_ice_volume.svg/220px-Plot_arctic_sea_ice_volume.svg.png)
(Graph from Wkipedia on Sea Ice).
[/url]
[url=https://en.wikipedia.org/wiki/Sea_ice#Yearly_freeze_and_melt_cycle]
Maxima in 1980 and 2017 were 33 thousand and 21 thousand square kilometers, and minima were 17 thousand and 5 thousand square kilometers (the latter the late summer of 2016). Note that recent maxima for winter ice are approaching old summer minima for ice.
Of course you may be referring to Antarctic ice, which is far larger and has protection from warm air masses by the Antarctic Convergence, a phenomenon that seems to have been in place for about 40 million years, that effectively keeps warm air masses from reaching Antarctica. I concede that there is no cause to believe that the Antarctic Convergence that shields Antarctica from warm air masses that would melt huge amounts of ice will disappear.
Most people live in the northern hemisphere, the biggest exception to that pattern in Indonesia. People most likely to feel the effects of global warming are in the northern hemisphere. But let me make a crude regression line. The ice minima have gone from 17 K km^2 in 1979 to 5 K km^2 in 2016... 12 K km^2 in 37 years gives roughly 1 K km^2 shrinking of Arctic sea ice in every three years -- there might be an ice-free Arctic Ocean (or practically so) in September 2031. Ice maxima are shrinking at a similar rate, so following the regression, the Arctic Ocean could be ice-free year-round in 2080. Sure, this is extrapolating a trend which is a risky proposition as a prediction, but I see no tendency to stop the progression of the trend.
In the Northern hemisphere, the fastest cooling in autumn is on the lands just south of the Arctic Ocean, typically in northern Russia (especially Siberia), Alaska, Canada, and northern Scandinavia and over extant bodies of ice (mostly Greenland and the ice on top of the Arctic Ocean. Open water does not cool as fast. The low albedo and heat capacity of water make reductions of temperature far slower than over ice and snow (almost 100% albedo) or dry land (low heat capacity).
If you have noticed some warm spells with slow-to-end summers (it is close to the middle of October and around here we have yet to have any frost), then this may reflect the slowness of Arctic air masses to flow into the middle latitudes. October is almost another summer month in Michigan, not that it was such when I was a child.
Winters are getting shorter and milder, and they are not reaching as far south as they once did. This is enough to change climate bands. If you are familiar with the Koeppen classification, then such is enough to have moved Nome, Alaska from ET (tundra) to Dfc (cold winter, short summer boreal). Reykjavik has gone from borderline between Cfc (mild winter with a short cool summer) and ET (tundra) to unambiguously Cfc. The borderline between Cfa (subtropical rainy with mild winters but above-freezing winters) and Dfa (fire-and-ice climates with adequate rainfall all year) as in Iowa or greater Chicago) has moved from Philadelphia through New York City to Boston. Tropical climates (no real winters) that barely grazed the Florida Keys are now at places like Fort Myers and Fort Pierce.
The projections make sense if one looks at shrinking ice in the Arctic Ocean and a shrinking ice cap in Greenland. The Arctic Ocean will still be a chilly sea, but not so chilly that its sea breezes will fully thwart inland locations from warming under the intense sunlight of the Midnight Sun to above 10C for at least a month in the summer, a temperature threshold close to the Arctic, subantarctic, and montane tree lines. Shorter and less intense winters would push mild winters into places like Chicago, Detroit, and Toronto. People will be asking what such antiques as snow plows were used for. Frost-free conditions will appear as far north as Orlando, Florida (I was tepted to say Tampa-St. Petersburg, bit those places will likely be inundated).
If you live in Indianapolis, you will not have to go about 300 miles south to find the Cotton Belt. It will have reached you.
(10-13-2017, 09:14 AM)Kinser79 Wrote: https://phys.org/news/2017-10-thousands-...ctica.html
Well apparently global WARMING means that there will be more ice in the polar regions some how. Never mind the physical properties of water.
It should be noted that sea ice does not form at 0C but at much colder temperatures as formed out of a saline solution.
https://en.wikipedia.org/wiki/Sea_ice
Of course, Arctic ice has been shrinking since at least 1980, with both seasonal maxima and seasonal minima getting lower in volume every year:
(Graph from Wkipedia on Sea Ice).
[/url]
[url=https://en.wikipedia.org/wiki/Sea_ice#Yearly_freeze_and_melt_cycle]
Maxima in 1980 and 2017 were 33 thousand and 21 thousand square kilometers, and minima were 17 thousand and 5 thousand square kilometers (the latter the late summer of 2016). Note that recent maxima for winter ice are approaching old summer minima for ice.
Of course you may be referring to Antarctic ice, which is far larger and has protection from warm air masses by the Antarctic Convergence, a phenomenon that seems to have been in place for about 40 million years, that effectively keeps warm air masses from reaching Antarctica. I concede that there is no cause to believe that the Antarctic Convergence that shields Antarctica from warm air masses that would melt huge amounts of ice will disappear.
Most people live in the northern hemisphere, the biggest exception to that pattern in Indonesia. People most likely to feel the effects of global warming are in the northern hemisphere. But let me make a crude regression line. The ice minima have gone from 17 K km^2 in 1979 to 5 K km^2 in 2016... 12 K km^2 in 37 years gives roughly 1 K km^2 shrinking of Arctic sea ice in every three years -- there might be an ice-free Arctic Ocean (or practically so) in September 2031. Ice maxima are shrinking at a similar rate, so following the regression, the Arctic Ocean could be ice-free year-round in 2080. Sure, this is extrapolating a trend which is a risky proposition as a prediction, but I see no tendency to stop the progression of the trend.
In the Northern hemisphere, the fastest cooling in autumn is on the lands just south of the Arctic Ocean, typically in northern Russia (especially Siberia), Alaska, Canada, and northern Scandinavia and over extant bodies of ice (mostly Greenland and the ice on top of the Arctic Ocean. Open water does not cool as fast. The low albedo and heat capacity of water make reductions of temperature far slower than over ice and snow (almost 100% albedo) or dry land (low heat capacity).
If you have noticed some warm spells with slow-to-end summers (it is close to the middle of October and around here we have yet to have any frost), then this may reflect the slowness of Arctic air masses to flow into the middle latitudes. October is almost another summer month in Michigan, not that it was such when I was a child.
Winters are getting shorter and milder, and they are not reaching as far south as they once did. This is enough to change climate bands. If you are familiar with the Koeppen classification, then such is enough to have moved Nome, Alaska from ET (tundra) to Dfc (cold winter, short summer boreal). Reykjavik has gone from borderline between Cfc (mild winter with a short cool summer) and ET (tundra) to unambiguously Cfc. The borderline between Cfa (subtropical rainy with mild winters but above-freezing winters) and Dfa (fire-and-ice climates with adequate rainfall all year) as in Iowa or greater Chicago) has moved from Philadelphia through New York City to Boston. Tropical climates (no real winters) that barely grazed the Florida Keys are now at places like Fort Myers and Fort Pierce.
The projections make sense if one looks at shrinking ice in the Arctic Ocean and a shrinking ice cap in Greenland. The Arctic Ocean will still be a chilly sea, but not so chilly that its sea breezes will fully thwart inland locations from warming under the intense sunlight of the Midnight Sun to above 10C for at least a month in the summer, a temperature threshold close to the Arctic, subantarctic, and montane tree lines. Shorter and less intense winters would push mild winters into places like Chicago, Detroit, and Toronto. People will be asking what such antiques as snow plows were used for. Frost-free conditions will appear as far north as Orlando, Florida (I was tepted to say Tampa-St. Petersburg, bit those places will likely be inundated).
If you live in Indianapolis, you will not have to go about 300 miles south to find the Cotton Belt. It will have reached you.
The ideal subject of totalitarian rule is not the convinced Nazi or the dedicated Communist but instead the people for whom the distinction between fact and fiction, true and false, no longer exists -- Hannah Arendt.