The updated NASA/Hansen climate model chart with the latest GISS and HadCRUT4 observations remains a testament to abject climate model failure by the anointed "experts"...chart includes updated GHG growth trends from IPCC AR5...not surprisingly, climate reality is very unkind to the CO2-centric computer simulation predictions...one could fairly surmise from the actual performance of models and experts that they can't predict squat...just say'n.....
No matter how many years go by, the trend towards ever worse climate model predictions continues.
Case in point: The NASA/Hansen climate model that was used by climate experts to convince the politicians, the media and pubic that the world was at severe risk for massive global warming if greenhouse gas (GHG) emissions were not drastically cut.
This model's predictions came to the forefront when NASA's James Hansen provided testimony to the U.S. Senate in 1988. As it was discovered much later, the Hansen testimony was stage-crafted for maximum fear-mongering impact, which should have been the first clue that there was a credibility issue regarding the climate model.
Before diving into the details, a short glance at the accompanying chart provides the critical policymaker insight:
- Essentially, the NASA model predicted temperatures would follow the bright green curve if GHGs were not curtailed. The cyan (aqua) curve datapoints are the predicted temperatures if GHGs were curtailed. Greenhouse gases have continued their accelerated growth, yet the observed temperatures (the green and pink circles) closely match the cyan curve. Simply, the model's predictions have been spectacularly wrong, worsening by the year.
The following provides more details:
The newly published 2014 IPCC AR5 summary report bemoaned the recent significant growth increase of GHGs. The IPCC established the per year growth, prior to 2000, to be at a 1.3% rate. The IPCC AR5 reports that GHG growth has now jumped to 2.2% per year through 2010 (see more details here).
[Editor: Speaking to CO2 emissions more specifically, using the 1999 year-end global CO2 emission level as the base year, CO2 emissions have grown at an average 3.0% per year pace as of the end of 2013. That's 14 years of exceptional growth. In contrast, the 14 years of CO2 growth prior to 1988 is only 1.8% per year (read below as to why prior to 1988).]
To say that GHGs have exceeded the 'business-as-usual" (BAU) scenario would be an understatement - according to the IPCC AR5, a 70% increase has taken place, on a per year basis.
Of course, the BAU scenario was made famous by during that 1988 U.S. Senate hearing.
Per Hansen: "We have considered cases ranging from business as usual, which is scenario A, to draconian emission cuts, scenario C, which would totally eliminate net trace gas growth by year 2000."
In a peer-reviewed article supporting his testimony, he stated that the 1970s and 1980s had an approximate annual growth average of 1.5% (prior to 1988). This was the paper's BAU 'Scenario A' that he spoke of in his testimony. In his written Senate statement, he included an appendix that verifies the ~1.5% BAU estimate for GHGs, plus a chart that depicted the scenarios A, B and C.
That chart is replicated above, with Scenario 'A' being the green curve; the 'B' scenario is the orange curve; and the cyan curve is the 'C' scenario, which represents the 'draconian' emission cuts Hansen states are required to minimize potential global warming.
As stated previously, the IPCC has confirmed the rapid, continuing growth of GHGs since the end of 1999, which per the NASA climate model, should have produced global warming equal to the bright green curve on the chart.
Instead, climate reality and natural climatic forces intruded - real world temperatures since 1988 resemble the cyan temperature curve of "draconian" emission cuts that Hansen's testimony implied would necessarily make global warming safe by end of 2014.
As it turns out, some 25+ years later at the end of 2014, we currently have achieved that implied 'safe' global warming that the climate modelers and experts predicted would not happen unless there were forced gigantic emission cuts.
Objectively, the empirical evidence leads to a couple of reality-based, undeniable and incontrovertible conclusions: policymakers should not rely on the unreliable climate models - they're egregiously wrong and not getting much better; and, climate experts truly do not understand the natural forces dominating the climate system.
Notes: This updated NASA/Hansen chart now uses the current HC4 and GISS V3 datasets, as of 12/31/14. Instead of plotting individual year datapoints for observed temperatures, plotted 3-year (36-month averages ending in December): this reflects an expectation that models can't predict accurately every annual period, but over longer 3-year periods the model and observation trends should better match. Starting in 1960, both GISS and HC4 3-year averages were offset to start at zero (0.0°C) anomaly. To reduce the clutter on chart, only 'even' year observed 3-year temperature datapoints were plotted. The small insert chart is data from IPCC AR5 summary report. The green, orange and cyan Hansen model plots came from this climate-doomsday site.