From NoTricksZone

By Kenneth Richard on 19. February 2024

“Here, we have demonstrated a major discrepancy between observation-based and climate model-based historical trends in near-surface atmospheric water vapor in arid and semi-ari regions.” – Simpson et al., 2024

A new study published in PNAS has demonstrated, once again, that climate models fail to simulate what happens in the real world with regard to fundamental climate change variables like water vapor. This is a devastating finding, as water vapor is the most significant greenhouse gas due to its alleged “feedback” capacity, accelerating warming well beyond what CO2 is said to be capable of alone.

The authors do not understate the significance of this climate modeling failure.

“This represents a major gap in our understanding and in climate model fidelity that must be understood and fixed as soon as possible in order to provide reliable hydroclimate projections for arid/semi-arid regions in the coming decades.”

Per state-of-the-art climate models, specific humidity (SH) should increase as a consequence of CO2-induced global warming. But 40 years of observations (1980-) show no increasing SH trend over arid/semi-arid regions.

Per state-of-the-art climate models, relative humidity (RH) should decline slightly as a consequence of CO2-induced global warming. But 40 years of observations (1980-) show not a slight declining trend, but a declining trend that is “about an order of magnitude more than the models on average.” In other words, the climate models are wrong by a factor of 10.

A few years ago another study documented how wildly wrong 102 state-of-the-art climate models have been with regard to a 60-year temperature trends (1958-2017) over tropical regions.

The models say the tropical warming rate should have been nearly 3 times larger than the observations show – “0.389 ± 0.173°C per decade (models) and 0.142 ± 0.115°C per decade (observed)” – due to the assumed feedback response to CO2 forcing over warm regions. Instead, there is a “clear and significant tendency on the part of the models to overstate warming.”

These authors also do not understate the significance of this modeling failure. Climate models are not even realistic.

“Instead, we observe a discrepancy across all runs of all models, taking the form of a warming bias at a sufficiently strong rate as to reject the hypothesis that the models are realistic.”

“[T]he major hypothesis in contemporary climate models, namely, the theoretically based negative lapse rate feedback response to increasing greenhouse gases in the tropical atmosphere, is incorrect.”

There may be no other branch of physical science with model-observation discrepancies (failures) this profound, this fundamental.

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