"It is very likely that there will be at least one sea-ice free Arctic summer out of 10 years for warming at 2 degrees C, with the frequency decreasing to one sea-ice-free Arctic summer every 100 years at 1.5 degrees C”
What's the reasoning behind this and how does it stand against the trends on the ice volume chart?
IPCC is said to be trying to improve their communication skills, but there is still room for improvement.
RE: "sea-ice free Arctic summer".
A literal interpretation would be that means zero ASI for every day between June 20 and September 21.
vs. September average going below 1 million km2 Extent.
vs. single day September minimum going below 1 million km2 Extent.
vs. September as a whole having zero ice.
vs. single day September minimum having zero ice.
So which is it? More precise specification of dates and definition of terms for statements about future ice losses would greatly improve clarity and reduce confusion about what is being said.
Speaking of confusion, this discussion belongs in the "When will the Arctic Go Ice Free" thread, not this one.