The consensus regarding the catastrophic global warming hypothesis is completely reliant on a proposed positive feedback producing runaway global warming that will destroy human civilization. Simply, is it happening?
(click on to enlarge)
To answer that question, one can examine the HadCRUT4 (HC4) empirical climate surface temperature record in order to identify if a positive feedback is evident.
The positive feedback would reveal its existence if global temperatures were accelerating to a tipping point of runaway warming, due to the ever-increasing human CO2 emission releases into the atmosphere,
As done with a previous article involving the analysis of the satellite record of temperature acceleration warming trends, the same can be accomplished with the HC4 global dataset. Thus, this analysis will also focus on both short and long-term warming trends to determine whether a constant state of acceleration is present.
First, the chart on the right represents satellite short and long-term acceleration plots used in the prior article; the chart of the left plots the short and long-term warming per century acceleration rates derived from the HC4 land/sea global dataset.
To attain the best apple-to-apple comparison, both charts are based on a start date that coincides with the advent of the satellite measuring technology in 1979 and through month-end February 2018.
Visually, the chart similarities of the two different temperature measuring methodologies are striking.
When scrutinized closely, there are differences, but those would be expected when one methodology is measuring lower atmosphere temps and the other methodology is based on near-surface temps of land and water.
As found in the prior analysis of the lower atmosphere temperature record, global surface temperatures accelerate at a faster pace and then always decelerate to a slower pace that may even indicate the potential of a cooling climate regimen.
More importantly, the HC4 temperature dataset verifies what the prior article on the satellite dataset established: despite multiple major warming El Nino events, and with over 60% of all 1850-2016 total CO2 emissions being released since 1979, there is absolutely zero indication of a positive feedback's existence producing a runaway, "tipping point" warming acceleration.
On the contrary, as of February 2018, all 3 short-term temperature HC4 acceleration trends at the end of February 2018 are well below their respective beginning trend values; and the ending February 2018 long-term per century trend is practically the same as the beginning trend value.
This finding matches with what was identified in the previous satellite analysis.
Additionally, as noted at the bottom of each chart, the positive correlations between the rolling monthly temperature trends and the cumulative growth of CO2 levels (ppm) are empirically not much different from zero; plus, both the long-term satellite and surface global trends seemingly have an inverse relationship with accumulating CO2 gases (a possible explanation?).
If correlation is an indicator of potential causation, then one would need to look at an entirely different reason other than CO2 emissions for any attempt to justify a belief in the runaway global warming scenario.
Analysis Summary:
Since a dangerous accelerating climate warming simply does not exist after decades of vast amounts of human greenhouse emissions being released, it is fair to conclude that the consensus of a catastrophic runaway global warming is debunked and entirely without any empirical merit or validity.
It still remains mere speculation after all these years, and should possibly be considered another candidate for the ash heap of group-think "consensus science."
Note: Excel used to calculate trends and to plot. HC4 dataset. The satellite dataset is 50/50 weighting of the RSS and UAH datasets. Monthly CO2 dataset. Calculated trends do not predict the future trends.