Very little happening in summer itself (as expected) as the melting ice surface and heat sensible heat gain in the mixed layer limit the surface air temperature change. (realclimate.org)
Climate sensitivity is a measure of the equilibrium global surface air temperature change for a particular forcing. (realclimate.org)
Just as changes in the rate of air temperature change over multi several year periods could be due to internal variability, even cessations (* which over a ten year plus period we haven't even seen) or drops in them (which we haven't seen) it's not likely. (judithcurry.com)