Posted onDecember 14, 2022| Comments Offon Arctic Report: primary productivity still high & sea ice flatline continues despite warmer temperatures
NOAAs annual Arctic Report Card is, for the most part, a valiant effort to turn good and ambiguous news into harbingers of climate change disaster. Primary productivity is up across most of the region (good news for wildlife) and despite Arctic temperatures being “twice as high” as the rest of the world in recent years, the summer sea ice ‘death spiral’ has failed to materialize.
Oddly, there is no bad news about polar bears (last mention was 2014). However, the media were told that the few hundred sea birds that died this year in the enormous Bering/Chukchi Sea region over the four months of summer in 2022 is a portend of climate change catastrophe–even though the authors of the NOAA report admit they have no conclusive evidence to explain the phenomenon. However, here are also some honest figures that are quite illuminating.
The graph at the bottom of this graphic, spread out rather than bunched up to make changes seem more dramatic, makes it much easier to see the lack of a declining trend in sea ice extent since 2007, and that winter (March) coverage has changed hardly at all.
My question – which part of this real world story of ecological disaster and recovery shouts fragile food web?
In my opinion the European supercomputer food web experiment is way too unrealistic to draw real world conclusions. New connections in the real world food web appear all the time, no food resource remains underutilised for long, even when the underutilised resource is a deadly toxic toad. Any breaks in the food web caused by climate change or disease or whatever, in the real world are rapidly filled.
There are a handful of species which are so specialised they actually would die if their food source was removed. For example, Koala Bears are so specialised at eating Eucalyptus leaves, they would likely all die if say a Eucalypt version of Dutch Elm Disease killed off all the Eucalyptus trees.
But are 17.6% of vertebrate species so specialised they cannot adapt to a small change in temperature? Are 27% of vertebrates about to die out? That seems highly implausible.
A few degrees of warming, if it occurs, is not an asteroid scale ecological catastrophe, or a million year duration volcanic eruption, it is a mild shift in climatic conditions, which life will have no problem adapting to if the paleo record is any guide. Just like life has already adapted to the many climatic shifts, introduced species and other disruptions which have occurred in Earth’s geological past.
A new study by a team of leading climate scientists suggests that the effect of carbon dioxide this century might be small if not undetectable when compared to natural climate variability.
Global surface temperature is and always has been the key climate parameter. Whatever is happening to the Earth’s climate balance, it must, sooner or later, be reflected in the global annual average temperature, and not just in regional variations. [emphasis, links added]
But therein lies what is to some an inconvenience as the changes in the global temperature this century are open to differing interpretations including the suggestion that increases in anthropogenic greenhouse gas emissions are not needed to explain the changes we have seen in the last 20 years or so.
It’s a conclusion that many would dismiss as coming from climate “skeptics,” or downright deniers.
But what if it’s the view of scientists from two of the world’s leading institutes researching climate change; the University of Oxford and the US National Center for Atmospheric Research? Then it must be taken seriously and not dismissed offhand.
It is important research because it is the trend in the increase of global temperature caused by anthropogenic [human-caused] greenhouse gas emissions that is the most important variable for policymakers considering the scale and timescale of action in the coming decades.
However, this vital parameter is uncertain because recent decades have shown that we are living through a period of considerable natural climate variability.
The researchers contend that recent temperature trends might indicate that there is no detectable increase in global temperature due to greenhouse gas emissions.
While this suggestion is interesting it must be said that the researchers get themselves in a muddle when estimating temperature trends this century.
On the one hand, they acknowledge the existence of the global temperature hiatus between 2000 – 2014, but on the other hand, they do not properly distinguish the effects of the natural El Nino eventsthat have taken place in the past seven years.
This is why they conclude there might have been an acceleration in global temperature increase over this period.
They say that most of the increase is not due to greenhouse gases but to aerosol emission reductions.
The combustion of fossil fuels releases greenhouse gases but it also causes pollution that cools the Earth,offsetting any warming.
They assess that aerosol emissions have contributed to an increase in the rate of anthropogenic warming since 2000 although they have large uncertainty.
When considering estimates of the amount of warming due to aerosol reduction along with natural climate variability, they find a solution with all the post-2000 temperature trends being due to natural variability alone.
They say (p 4283) it’s a credible hypothesis that global temperature changes since 2000 could be “arising largely from internal variability.”