Guest Post by Bob Tisdale
Alternate Title: Climate Models Undermine the Hypothesis of Human-Induced Global Warming
According to the hypothesis of human-induced global warming, manmade greenhouse gases create an energy imbalance at the top of the Earth’s atmosphere, which causes the Earth to retain heat. One of the hypothetical results of that retained heat is global surface warming. The opening sentence of the abstract of Trenberth et al. (2014) Earth’s Energy Imbalance confirms that statement. It reads:
Climate change from increased greenhouse gases arises from a global energy imbalance at the top of the atmosphere (TOA).
Another hypothetical result of the energy imbalance at the top of the atmosphere is the accumulation of heat in the oceans. In the post Climate Models are NOT Simulating Earth’s Climate – Part 3, we presented the top-of-the-atmosphere energy imbalance of the climate models stored in the Climate Model Intercomparison Project Phase 5 (CMIP5) archive. (The CMIP5-archived models were used by the Intergovernmental Panel on Climate Change (IPCC) for their 5th Assessment Report.) As is commonly done by the climate science community, we then converted the simulated top-of-the-atmosphere energy imbalance to ocean heat uptake, and we discovered that there was a very wide range of modeled ocean heat accumulation and losses. See Figure 1, which is Figure 1.24-14 from Part 3. It is for the depths of 0-700 meters.
In Part 3 of this series, we discussed how 8 of the models were outliers, with simulated ocean heat accumulation either way too high or with the simulated oceans losing heat. And as you’ll recall, the ocean heat accumulation for the full oceans showed the same outliers. (See Figure 1.24-7 from that post.) So in Part 3, we eliminated the outliers and found that the remaining climate models all showed ocean heat accumulation that was higher than observed, with the average (the consensus, the groupthink) being twice as high as the observed ocean heat accumulation for the period of 1955 to 2015. In other words, the remaining models were too sensitive to manmade greenhouse gases by a wide margin.
In this post, we’re going to take another look at the outlying climate models and illustrate a peculiarity inherent in those models.
CLIMATE MODEL DRIFT
As a preface, we discussed climate model drift in Part 3 of this series and that model drift may be the cause for the models with the outlying ocean heat accumulation and losses. See the discussion under the Part 3’s heading of THE IPCC’S PRESENTATION IS TOTALLY DIFFERENT. Climate scientists adjust climate model outputs to account for drift. That is, instead of correcting a problem that has plagued climate models for decades, they tweak the model outputs.
If the models presented in this post are suffering from drift, then this post exposes one of the problems of drift.
THE 8 OUTLIERS
Figure 2 shows the ocean heat accumulation of the 8 outlying climate models, for the depths of 0-700 meters, and for the period of 1955 to 2015. They include BCC-CSM1-1, BCC-CSM1-1-M, FIO-ESM (3 runs), MIROC5 (3 runs), MIROC-ESM, MIROC-ESM-CHEM, NorESM1-M, and NorESM1-ME.
Five of the models show the oceans losing heat from 1955 to 2015, while three of the models show way too much ocean heat accumulation. (You’ll note that I’ve changed the color-coding for this post.)
And as discussed in Part 3 of this series, the reason the 3 models showed too much ocean heat accumulation was because their simulated top-of-the-atmosphere energy imbalances were too high. Conversely, the reason the 5 models showed the oceans losing heat was because their simulated top-of-the-atmosphere energy imbalances were negative. See Figure 3.
In the real world, according to the hypothesis of human induced global warming, if the Earth had a negative energy imbalance (that is, the outgoing energy was greater than incoming), wouldn’t global surfaces be cooling? They aren’t in the 5 models with the negative energy imbalances. See Figure 4.
In fact, regardless of whether the climate models are showing the extremely high positive top-of-the-atmosphere energy imbalances or showing negative imbalances, all of the models show global surface warming. In other words, global surface warming is not dependent on a positive energy imbalance in 5 of the climate models used by the IPCC for their 5th Assessment Report.
THE FOUR EXTREMES
According to the hypothesis of human induced global warming, in the real world, if the Earth had a very high positive energy imbalance (much more incoming than outgoing radiation), wouldn’t global surfaces be warming at a very high rate? They are not in the models with the high energy imbalance.
To help drive home the point of this post, Figure 5 illustrates the ocean heat accumulation and losses from 4 of the climate models: MIROC-ESM, MIROC-ESM-CHEM, NorESM1-M, and NorESM1-ME. Those are the models with the extremely high simulations of ocean heat accumulation and losses.
And Figure 6 shows the reasons for the extreme ocean heat gains and losses in those models: the high positive and negative simulated energy imbalances at the top of the atmosphere. They are roughly +2.5 watts per square meter and -2.5 watts per square meter for those four models.
Yet, as shown in Figure 7, regardless of whether the average simulated energy imbalances for the period of 1955 to 2015 are roughly +2.5 watts per square meter or -2.5 watts per square meter, they show comparable rates of global surface warming for that period.
Bottom line: According to some of the climate models used by the IPCC for their 5th Assessment Report, global surface warming for the period of 1955 to 2015 is NOT dependent on the simulated top-of-the-atmosphere energy imbalance. In other words, those climate models undermine the hypothesis of human-induced global warming.
If climate model drift is the reason for those odd relationships, the modelers need to fix the models, not adjust the outputs.
OTHER POSTS IN THIS SERIES
Climate Models are NOT Simulating Earth’s Climate – Part 1 illustrated and discussed how climate models fail to simulate the spatial patterns of warming and cooling of the surfaces of the global oceans over the past 3+ decades and why they should simulate them.
Climate Models are NOT Simulating Earth’s Climate – Part 2 presented time series graphs of sea surface temperatures (not anomalies) globally and on hemispheric and individual ocean-basin bases, from 1982 to 2015, showing that climate models fail to properly simulate the warming rates (far too much warming in most cases) and the actual temperatures of the surfaces of Earth’s oceans.
Climate Models are NOT Simulating Earth’s Climate – Part 3 illustrated and discussed how climate models, excluding the outliers presented in this post, show way too much ocean heat accumulation since 1955. This strongly suggests that most climate models are far too sensitive to manmade greenhouse gases.