Latest posts by H. Sterling Burnett (see all)
Even while misstating the facts concerning 2017’s temperature, James Hansen et al. make a surprising admission: the sun has a strong influence on temperature that may overwhelm rising greenhouse gas emissions and lead to decade-long hiatus in temperature rise.
Hansen and his colleagues say 2017 was the second or third warmest year since widespread surface instrumental records were kept. They attribute this warming to rising greenhouse gas concentrations, stressing it was not helped along by any boost from a tropical El Niño as was arguably the case in 2015 and 2016.
Their claim is false. According to the National Oceanic and Atmospheric Administration, an 11 week springtime El Niño anomaly occurred from April through July of 2017. Because it didn’t last five months, NOAA did not classify it as an El Niño event, but El Niño conditions persisted for three months, affecting both ocean and land temperatures, the latter of which take longer to recover from. El Niño conditions thus affected temperatures well into 2017.
More interesting than their temperature claim was the Hansen team’s admission solar variability has a powerful influence on temperatures. In the past, Hansen and others on his team have dismissed solar activity as not having any significant long-term impact on global temperatures, but in this paper Hansen et al. write:
The record 2016 temperature was abetted by the effects of both a strong El Niño and maximum warming from the solar irradiance cycle. Because of the ocean thermal inertia and decadal irradiance change, the peak warming and cooling effects of solar maximum and minimum are delayed about two years after irradiance extrema. [S]olar variability is not negligible in comparison with the energy imbalance that drives global temperature change. Therefore, because of the combination of the strong 2016 El Niño and the phase of the solar cycle, it is plausible … the next 10 years of global temperature change will leave an impression of a ‘global warming hiatus.’”
In one paragraph, Hansen acknowledges solar variability and oceanic oscillations could overwhelm any effect greenhouse gas concentrations could have on temperatures. And by the way, the result would not be just an “impression of” a global warming hiatus. It would be a real hiatus.