Climate Models Don’t Work

Guest essay by Larry Hamlin (*)

In February 2016 climate scientist Dr. John Christy presented testimony to Congress demonstrating that climate models grossly exaggerate and over estimate the impact of atmospheric CO2 levels on global temperatures . Dr. Christy noted in his testimony that “models over-warm the tropical atmosphere by a factor of approximately 3″.


NOAA climate activist scientist Dr. Gavin Schmidt challenged Dr. Christy’s work claiming that it was “partisan” and using vague statistical arguments claimed that Christy’s work improperly presented the performance of climate models. These claims by government scientist Dr. Schmidt peaked the interest of statistics expert Steven McIntyre who was one of the most prominent  experts to expose the flawed science (proxy shenanigans) and mathematics (statistical errors) behind the now disgraced thousand year long global temperature profile infamously known as the “hockey stick” (

Mr. McIntyre conducted a review of Dr. Schmidt’s claims ( noting that his analysis evaluates the diagram used by Schmidt allegedly supporting his claims against Christy by “first discussing the effect of some sleight-of-hand and then showing that Schmidt’s diagram, after removing the sleight-of-hand and when read by someone familiar with statistical distributions, confirms Christy rather than contradicting him.”

Additionally Mr. McIntyre provided expert findings of his review of the statistical results of Dr. Christy’s work as showing that climate models were indeed  “over warm” in their projections as follows:

  • a model run will be warmer than an observed trend more than 99.5% of the time;
  • will be warmer than an observed trend by more than 0.1 deg C/decade approximately 88% of the time;
  • and will be warmer than an observed trend by more than 0.2 deg C/decade more than 41% of the time.

McIntyre concluded:

“The bottom line is that Schmidt’s diagram does not contradict Christy after all, and, totally fails to support Schmidt’s charges that Christy’s diagram was “partisan”.”

Climate scientist Dr. Judith Curry has prepared a new presentation (highlighted in 56 slides) on climate issues ( which addresses many climate science topics including global temperatures and the growing divergence between actual temperature measurements and the overly warm exaggerated temperature projections of climate models.

She notes in her presentation that the latest 2013 UN IPCC AR5 climate report presented information showing (slide #24) how climate models over state and exaggerate projections of global temperatures versus actual measured data. Dr. Christy’s Congressional testimony data on climate model global temperature exaggerations is also included in her presentation (slide #25).


In addition to climate models over exaggerating global temperature projections these models also have failed to account for the behavior and impact of major natural climate variation events such as those associated with ENSO as discussed in the Watts Up With That  article “Once Again El Nino Didn’t Do What Was Forecast. Why?.

In his article Dr. Ball notes that

“The IPCC claimed with 90% certainty that global warming is due to human CO2. Lack of data combined with omission or lack of understanding of major mechanisms are major reasons why all past, present, and future predictions are wrong. The same is true of major events within the Earth/atmosphere system like El Nino or ENSO. As it is more frequently said these days, if your predictions are wrong the science is wrong.”

Naturally occurring El Nino events have and continue to influence increasing global temperatures and temperature trends and have done so multiple times every decade. (


Dr. Curry’s presentation provides global temperature data that show natural climate variation associated with the strong El Nino’s of 1997-1998 and 2015-2016 as well as other smaller El Nino events have major impacts on recent increasing global temperatures and temperature trends (slide #13). Some climate alarmists have claimed that man made CO2 emissions are causing recent increasing global temperatures and temperature trends but these claims inappropriately ignore the significant strong EL Nino influences on recent temperatures.


The impact of El Nino events is present in both surface temperature and atmospheric temperature data measurements (slide

#14) as well.


Climate alarmist media such as The New York Times drone on about recent record high global temperatures in 2016 being caused by man made CO2 emissions. ( )  However these alarmist claims are based upon arbitrarily minimizing and understating the importance of the strong El Nino of 2015-2016 as the driving force behind these recent warming temperatures and temperature trends as clearly illustrated in Dr. Curry’s presentation.

Analysis of global temperature data shows clear exaggeration and over statement of projected temperatures by climate models versus actual measurements as demonstrated by both Dr. Christy and Dr. Curry’s work. Additionally the significant impact of natural climate events, such as El Nino’s, on recent global temperatures and temperature trends is clearly evident but unaddressed in climate model results as noted by Dr. Ball.

Climate alarmist scientists and media seek to downplay and ignore the demonstrated failures of climate models to provide valid temperature projections as blatantly exposed by the ever increasing temperature divergence of these models results from actual measurements as well as for these models failures to address natural climate event impacts such as El Nino’s.

Dr. Curry notes that the climate change issue is a “wicked” one (slide #46) and that both the problem and solution have “been vastly oversimplified”. Proposing costly and bureaucratically burdening climate policy actions based on poorly performing and scientifically inadequate climate models is simply not justified.