Read here. Often climate alarmists will point to warming ocean temperatures, or sea ice melting, and actually conclude that these conditions are caused by human CO2. Although there is no scientific evidence that even remotely suggests CO2 causes ice to melt or oceans to warm, that does not dissuade alarmists from spreading the bogus claims to the gullible MSM.
Real scientists are actually investigating the observed ocean temperature cycles across the world, and in the Arctic areas at least, the evidence is overwhelmingly pointing to the natural Atlantic Multidecadal Oscillation (AMO) as the culprit. (click image to enlarge)
"We present area-averaged time series of temperature for the 100–150 m depth layer of the Barents Sea from 1900 through 2006. This record is dominated by multidecadal variability on the order of 4C which is correlated with the Atlantic Multidecadal Oscillation Index."...."The hint in the conclusion (which the authors stop short of defining) is that the pattern of data, seen below, might be linked to the recent pattern of Arctic sea ice melt and some partial recovery seen in the last two years."