Mr Milk said..
We'll compare it with map making.
Our understanding of terrain and spacial geometry is advanced. It's also an easy concept with essentially few variables involved in measuring something with good accuracy that is essentially static. To compare that with a complex, chaotic constantly changing system, that is effected by a huge number of other complex and chaotic forcings is hardly relevent. Our accuracy in even measuring the various climate variables is horrible, let alone being able to model the system with any meaning.
Mr Milk said..
And a bump in arctic sea ice in one year doesn't, of itself, mean that the ice cover isn't on a downward trend.
It's not a "bump", thats just the headlines you read. The data does not lie... the Antarctic has been static, there is no trend of declining ice at all in the Antarctic. Facts are facts, check the data.
The Arctic has been in a recent declining trend for sure. However it seems to have peaked back in 2013 and the trend seems to have stalled or is reversing. There was a similar trend back in the 40's, so it's not unprecendented.
What people don't see or is not reported is that even with the Arctic ice decline, decadal averages have not moved more than 20% away from the 1980 to 2010 average. Reports of imminent ice free Arctic and catastrophic ice loss are groundless, especially when the record summer minimums are usually balance with a high winter maximum.