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Messages - roger white

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1
Antarctica / Re: Sea Ice Extent around Antarctica
« on: February 14, 2020, 11:01:55 AM »
Or to put it another way 2019 is the 20th highest sea ice in the satellite record.
With the 40 year record showing sea ice increasing in extent.
( 2010's more ice than 1980's).

2
Arctic sea ice / Re: 2020 Sea ice area and extent data
« on: February 12, 2020, 12:14:09 PM »
Very interesting what a cold winter it is in the arctic with the sea ice extent greater than 9 out of the 10 past years.
Indeed the sea ice this winter seems greater than the 2010's average.
Looks like a 2-3% decadal decrease in arctic sea ice since the 80's & no signs of acceleration of this trend decade by decade.

3
Antarctica / Re: Sea Ice Extent around Antarctica
« on: January 31, 2020, 08:00:31 AM »
So, sea ice extent in the antarctic has remained pretty  much the same over the past 40 years.

4
Arctic sea ice / Re: Global sea ice area and extent data
« on: January 28, 2020, 01:13:15 PM »
So  nearing the winter minimum ice cover in the arctic is currently greater than in 2005 or 2006 & greater than most of the 2010's.

The decadal decline in global sea ice appears to be around 2.5% per decade since the satellite measurements began in 1979.

Noteworthy, but begs the question of whether 1979 was itself a low point from which to begin measuring?


5
Arctic sea ice / Re: Global sea ice area and extent data
« on: October 31, 2019, 10:35:12 AM »
Just running over the latest global sea ice figures as we are close to the end of the freezing season (?) & also near the end of the 2010's decade.

Your decadal figures show:

Global sea ice extent loss ( averages 1980's-2010's) of 6%...or 1.5% loss per decade...( not evenly of course).

Do we have any idea of the shrinkage of expansion of global sea ice in other time frames - ie
1800's-1840's...1900's-1940's......etc to see if this kind of change is unusual?

6
Arctic sea ice / Re: 2019 sea ice area and extent data
« on: July 25, 2019, 06:45:23 PM »
September Average Extents, 2002-2018: Calculated by Walt Meier and Julienne Stroeve, National Snow and Ice Data Center. All values in this table estimated based on the NSIDC Sea Ice Index Version 3.ge Extents, 2002-2018:

Would anyone like to comment on these figs from NSIDC

2008 4.69
2009 5.25
2010 4.87
2011 4.56
2012 3.57
2013 5.21
2014  5.22
2015  4.62
2016  4.53
2017  4.82
2018  4.71

7
Arctic sea ice / Re: Global sea ice area and extent data
« on: June 10, 2019, 08:38:37 AM »
Thanks for all the comments. Of course all phenomena merit investigating, even 4 years of shrinking antarctic sea ice. Though surely this is too short a period for anyone to jump to conclucions.
Indeed the satellite record is very short surely when measuring the planet's climate.
My main point though remains. On it's own the decrease in global sea ice totals reported on this forum is.. ( 3% day to day -7% on other measures as pointed out ) from the 80's to the 2010's.
I'm now clear on that.

<snip, you're lagging again, the Hiatus BS is no longer a serious climate risk denier argument; N.>

8
Arctic sea ice / Re: Global sea ice area and extent data
« on: June 06, 2019, 05:08:55 PM »
Thanks to all for comments.

You seem to agree that on the stats regularly published on this site showing the decadal day to day changes, the figure is around 3% over 30 years from the satellite data.

But 7% or so when comparing maxima & minima.

Leaving aside all the snide comments, & responses to unasked questions- such as why the arctic decreases are quite large whereas the antarctic increases ( decadally) are also quite large - this still seems a small ( ish ) figure, without context of previous comparable measurements.

The comments that the picture has changed in the last 4 years seem remarkably silly. 4 years is no basis to measure such things. 30 years hardly seems very long..when there is no proper answer to the question.

Is a 3 or 7% variation unusual comparing several 30 year periods?

It also must seem suspicious that whenever a stat goes in the direction of a hypothesis ( the arctic ) the trend is real. But when it doesn't ( the antarctic ) special factors must be at play.




9
Arctic sea ice / Re: Global sea ice area and extent data
« on: June 04, 2019, 05:15:08 PM »
Which data are you using to get to the 6% decline in global sea ice from the 80's to 10's?
I am only calculating on the stats used on this site.

The latest post showed:
1980's 24,033,325
2010's 23,331...

3%.

Of course this varies from day to day. Other stats show 2-3% decline.

I'm not impressed by throwaway lines about " denial" or " sceptics."

My question simply follows the stats released on this forum. 

10
Arctic sea ice / Re: Global sea ice area and extent data
« on: June 02, 2019, 02:51:00 PM »
There are all sorts of very clever replies explaining why any increase in the antarctic sea ice is not significant, while the decrease in the arctic is very significant.
Yet the total for global sea ice which are published on this site continue to show:

No change ( sometimes tiny + or tiny -) in global sea ice between the 80's & 90's
2-3% decrease in global sea ice between the 80's & 2010's.

Contributors have confirmed there are no really accurate measures for global sea ice rise or fall in previous 40 year periods, to see if a 2-3% decrease is unusual.

So we seem to be left with observed very short term ( 40 years ) record of a decline in global sea ice of between 2 & 3%.

I wonder what, in a purely objective world, with no emotional commitment to hypotheses of warming, whether a scientific ( or indeed lay ) observer would make of such a trend.


11
Arctic sea ice / Re: Global sea ice area and extent data
« on: May 29, 2019, 05:16:58 PM »
The decadal figs given above your quote indicate either little or no decrease in sea ice from the 80's the 90's ( some days show an increase in global sea ice between those decades ) & a 2% decrease in sea ice over the past 40 years.
Do these stats justify your comments?
Do we have for example comparisons ( accurate ) of global sea ice changes between - say - the 1910's ^ the 1950's? To judge if a 2% swing is worth remarking upon? Or the 1880s - 1920's?
Or the 1840's to the 1880's?


12
Arctic sea ice / Re: Global sea ice area and extent data
« on: May 06, 2019, 08:15:21 AM »
By the latest chart the decade on decade reduction in sea ice extent globally looks like this:
1980's 22,126,425
1990's 22,131,370
2000's 21,872,152
2010's 21,562,353.

So sea ice extent globally went UP in the 1990's?
The decline certainly looks small to the layman...& what would one expect to be " normal" variations from decade anyway...of this magnitude...?


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