The following summarizes selected considerations [including: (1) transient masking factors, (2) misinterpretations of paleo & observed climate sensitivities, (3) misinterpretations of the stability of the WAIS and (4) underestimates of the likeliness of continued high anthropogenic radiative forcing] as to why our climate change situation is more dire than the IPCC AR5 consensus (which represents scientism) currently acknowledges:
1. Masking mechanisms which allow scientists to match model results to paleo & observed conditions while calibrating for relatively low climate response (while either ignoring many masking mechanisms [such as paleo-dust & paleo-SOA], or diminishing their effectiveness in the models); and which allow decision makers to procrastinate in exactly the timeframe when it was critical that they take immediate action.
Hodzic, A., Kasibhatla, P. S., Jo, D. S., Cappa, C. D., Jimenez, J. L., Madronich, S., and Park, R. J.: Rethinking the global secondary organic aerosol (SOA) budget: stronger production, faster removal, shorter lifetime, Atmos. Chem. Phys., 16, 7917-7941, doi:10.5194/acp-16-7917-2016, 2016.
http://www.atmos-chem-phys.net/16/7917/2016/W.R.T. GMSTA: Specific masking mechanisms include:
(a) Temporary (observed at least from roughly 1998 to 2013) atmospheric conditions in the Tropical Pacific that not only temporarily increased the frequency of lower level cloud cover with negative feedback, but also above average La Nina-like conditions and generally negative PDO values; which, accelerated the sequestration of heat in the ocean, which was partially release during the 2015-16 El Nino.
(b) The temporary acceleration of anthropogenic aerosol emissions (largely associated with coal-fired power plants in both in China and elsewhere) that temporarily induced both negative forcing & negative feedback.
(c) A temporary acceleration of the absorption of carbon dioxide by land-based plants associate both with higher atmospheric carbon dioxide concentrations, and with global warming.
i. Keenan et. al. (2016) "Recent pause in the growth rate of atmospheric CO₂ due to enhanced terrestrial carbon uptake", Nature Communication, doi:10.1038/ncomms13428.
http://www.nature.com/articles/ncomms13428Erik Hans Hoffmann, Andreas Tilgner, Roland Schrödner, Peter Bräuer, Ralf Wolke and Hartmut Herrmann (November 2016), "An advanced modeling study on the impacts and atmospheric implications of multiphase dimethyl sulfide chemistry", PNAS, vol. 113 no. 42, 11776–11781, doi: 10.1073/pnas.1606320113
http://www.pnas.org/content/113/42/11776(d) Decadal scale thermal inertia fluctuations associated the ocean, atmosphere and cryosphere.
(f) A probable underestimation of both natural and anthropogenic negative aerosol forcing and feedback.
W.R.T. SLR: Specific masking consideration include:
(a) The tidal gauges around the world are located so as to be biased against the Greenland Ice Sheet, GIS, fingerprint contribution, likely underestimating SLR;
(b) In 2011 atypical atmospheric river event deposited large quantities of snow in Eastern Antarctica, thus underestimating SLR trends.
(c) Isostatic rebound associate with ice mass loss in the WAIS can mask the true ice mass loss measured by either gravity (GRACE) or ice surface elevation.
(d) If the WAIS is a major contributor to SLR this century, then due to the fingerprint effect this contribution could be increased by up to 40% in the NH.
W.R.T. Anthropogenic Bias: Other masking issues relate to the phrase "To err is human" in that AR5's projections contain so many caveats that it obfuscates the seriousness of our climate change challenge. Specific anthropogenic masking factors include:
(a) The referenced standards for reporting observed GMST have been demonstrated to be biased on the low side.
(b) Anthropogenic forcing began earlier than assumed in AR5.
(c) Common use of old values for GMSTA above pre-industrial.
(d) Common use radiative forcing scenarios that err too far on the side of least drama.
(e) Focus on linear Frequentist theory thereby underreporting the findings of chaos theory, of Bayesian analysis; of non-linear theory and of preliminary research that does yet meet the Frequentist confidence levels for evidence.
(f) Organized intimidation of climate scientists by denialists have contributed to ESLD reporting.
2. The TCR, ECS and ESS are all likely higher than consensus science is willing to currently acknowledge, due to a combination of:
(a) Masking factors biasing the recent observed climate change.
(b) A misinterpretation of paleo-data with regard both the role of negative forcing from paleo dust and the role of Lorenz strange attractors in progressively ratcheting Earth Systems into higher states (such as an early albedo flip for the Arctic; and increased frequencies for strong El Nino events).
(c) The synergistic acceleration of non-liner positive feedback mechanisms (including Polar Amplification and permafrost degradation).
3. Instability of the WAIS could lead to a rapid acceleration of Hansen's ice-climate feedback mechanism within coming decades. The likely earlier than expected collapse of key portions of the WAIS are due to reasons such as:
(a) The formation of the ozone hole over Antarctica accelerated the westerly winds over the Southern Ocean that together with the Coriolis effect drove warm circumpolar deep water, CDW, to the exposed ice of many key marine glaciers and associated ice shelves.
(b) The likelihood that GMSTA will approach (or exceed) 2.7C above pre-industrial conditions which per DeConto (2016) should trigger hydrofracturing and cliff failures of key WAIS marine glaciers.
(c) The rapid ocean heat uptake by the Southern Ocean's CDW (which is partially related to a climate change related increase in intense ENSO events).
4. Anthropogenic radiative forcing would continue at higher than advisable levels, and for a longer than expected periods, due to such trends as:
(a) The transfer of industry from first world to third world countries (thus allowing high emissions to continue for some decades to come).
(b) An increase in fracking and farming led to an increase in methane emission rates.
(c) The domination of US policy by the GOP (soon including by Donald Trump) and their protection of the fossil fuel industry.
(d) The relatively rapid decline of the coal industry (particularly in China) that has accelerated aerosol forcing.
Thus we should not over rely upon the finding of AR5, as it errs on the side of least drama.