Half a dozen recent papers show that man’s responsibility for Arctic ice melt has in reality been grossly exaggerated and that Arctic sea ice science is fraught with far greater uncertainty than we are often led to believe.
One paper even notes that Arctic sea ice decline could be over.
Alarmists often claim that almost all of the global warming occurring over the past 50 years is almost completely due to human activity, i.e. the burning of fossil fuels” Here they ignore the high levels of solar activity over the course of the entire 20th century and the warm phases of the oceanic cycles experienced over the past decades.
With such an obvious sloppy scientific approach, it is of course little wonder climate science is met with so much skepticism.
Arctic exaggerations and uncertainty
Two days ago Kenneth Richard posted on a number of papers that do show that man’s attributed share to Arctic warming has indeed been wildly overstated, and that estimates are fraught with great uncertainty. They also show ocean and solar cycles very much at play.
Arctic temperatures have been steady over the past decade. Image Source: Climate4you
As Kenneth wrote, the instrument-bare Arctic has been (mis)used to fudge global temperatures upwards. However other scientists have recently shown in half a dozen papers that only about 50% of the warming and sea ice losses for the Arctic region may be anthropogenic and that the rest of the warming and ice declines are attributed to natural factors.
The real figure is probably even less than 50%, which is a far cry from being completely due to man, as is often claimed.
Substantial portion “naturally driven”
According to Kenneth’s research that is based on a short review of the peer-reviewed scientific literature, there appears to be widespread agreement that a “substantial portion” of post-1979 Arctic-wide climate changes are naturally driven.
A scientific report by Indrani Roy appearing in Nature, March 2018, for example assigned about half of the blame for the Arctic melt of the past 15 years to natural factors. The paper itself implies that the estimate harbors uncertainty when it stated that 50-60% of the ice loss “is likely” caused by anthropogenic factors.
Here the anthropogenic factors also include soot, which is different from GHG effects. One could thus have an easy time arguing that the figure for CO2 greenhouse gas warming is less than 50%, even far less.
Looking back only to 1979
In another published paper by Qinghus Ding et al also appearing in Nature, the authors attributed the “recent” rapid Arctic ice melt over northeastern Canada and Greenland “around 50%” to natural variability.
Once again uncertainty is implied by the word “around”. Also the authors examine the ice conditions going back to only 1979. Surely if they looked back further, the natural factors would look even stronger.
Only “approximately” half due to man
Next a paper by Jennifer E. Kay and co-authors appearing in the Geophysical Research letters (2011) looked at Arctic sea ice going back only to 1979 and it too attributed “approximately half” of the melt to “internal variability”.
That’s a far cry from man being almost 100% responsible for the melt we often here from the media. And again, skeptical scientists would have an easy time arguing that the man-made share is significantly less. Many scientists have done so already — pointing to solar activity and powerful oceanic cycles.
Scientists playing down the huge uncertainty
It’s important to recall that datasets from the Arctic are scant at best, and have huge voids. Rough guesses are the best scientists could possibly some up with under such circumstances. Yet, too often do the authors come across as being “pretty sure” when in fact that’s impossible.
But some scientists do let the great scarcity of data interfere with their certainty. In another paper (2015) appearing in the Proceedings of the National Academy of Sciences, the authors found that internal variability “might be” 49% responsible for the September Arctic sea ice decline since 1979, and then stated that the sea ice trend could actually see a hiatus in the future.
A Nature paper by Quighus Ding and co-authors (2017) found: “Internal variability dominates the Arctic summer circulation trend and may be responsible for about 30–50% of the overall decline in September sea ice since 1979″.
And maybe not.
Greenland anthropogenic melt too small to be detectable
Finally Kenneth presented a 2016 paper by Thomas Haine appearing in Nature, where he found that the anthropogenic melt from the Greenland ice sheet “is still too small to be detectable”.
Soon: Natural factors dominate
April 22, 2018 at 07:39AM