Uncoupled: CO2 And Sea Ice
Anthropogenic CO2 emissions have risen linearly since the mid-1940s.
According to climate models, anthropogenic CO2 emissions drive trends in polar sea ice. The sea ice extent in both the Northern and Southern Hemispheres should therefore gradually decline (linearly) as human emissions rise.
However, neither the Arctic nor Antarctic sea ice trends appear to be cooperating with these modeled expectations.
In newly published papers, scientists have reported that Arctic sea ice extent grew during the decades from the 1940s to the 1980s before declining after the 1980s. The Arctic sea ice trend has thus undergone an oscillation rather than a linear recession, contradicting the models.
Furthermore, the instrumental record indicates that Arctic temperatures have stopped rising since about 2005.
On the other side of the planet, the sea ice surrounding Antarctica has been growing since the 1970s, or for nearly 40 years now. This sea ice expansion coincides with an overall Southern Ocean cooling trend of about -0.3°C per decade since 1979.
Again, the climate models that stipulate changes in CO2 concentrations are what drive polar sea ice trends have been contradicted by observational evidence. As Connolly et al. (2017) conclude:
“[C]urrent climate models are still quite poor at modeling past sea ice trends.”
Climate models may also be quite poor at modeling current sea ice trends.
Read papers at No Tricks Zone