High Climate Sensitivity
Oct 2013 Discovery that agricultural practices help form clouds could change the way we calculate global warming- climate is more sensitive.
CLIMATE EMERGENCY INSTITUTE
The health and human rights approach to climate change
2012 Climate Sensitivity Estimated From Earth's Climate History
2008 James E. Hansen and Makiko Sato
Target Atmospheric CO2: Where Should Humanity Aim? James Hansen
Abstract: Paleoclimate data show that climate sensitivity is ~3°C for doubled CO2, including only fast feedback processes. Equilibrium sensitivity, including slower surface albedo feedbacks,is ~6°C for doubled CO2 for the range of climate states between glacial conditions and ice-free Antarctica.
Equilibrium sensitivity 6°C for doubled CO2 is relevant to the case in which GHG changes are specified. That is appropriate to the anthropogenic case, provided the GHG amounts are estimated from carbon cycle models including climate feedbacks such as methane release from tundra and ocean sediments. The equilibrium sensitivity is even higher if the GHG feedback is included as part of the climate response, as is appropriate for analysis of the climate response to Earth orbital perturbations. The very high sensitivity with both albedo and GHG slow feedbacks included accounts for the huge magnitude of glacial-interglacial fluctuations in the Pleistocene in response to small forcings
18 Dec 2015 NASA research Examination of Earth's recent history key to predicting global temperatures. The sensitivity is 70% higher than IPCC estimates used
Jan 2014 Drew Shindell Inhomogeneous forcing and transient climate sensitivity Transient C Sens is higher than IPCC estimates
7 April 2016 Global warming may be far worse than thought, cloud analysis suggests. Climate change projections have vastly underestimated the role that clouds play,
31 Dec 2013 Solution to cloud riddle reveals hotter future: Global temperatures to rise at least 4 degrees C by 2100
8 April 2016 Observational constraints on mixed-phase clouds
imply higher climate sensitivity Article on above paper
June 2016 Deep time evidence for climate sensitivity increase with warming
Jun 2016 Projection and prediction: Climate sensitivity on the rise
5 May 2015 Climate variability and relationships between top-of-atmosphere radiation and temperatures on Earth
Aug 2013 Time-dependent climate sensitivity and the legacy of anthropogenic greenhouse gas emissions
Nov 2016 -Nonlinear climate sensitivity and its implications
for future greenhouse warming
Equilibrium climate sensitivity for warm climates is much higher for today's warm climates
'For warm climates, the value (S warm) is more than two times larger.
Dec 2017 Nature, Brown & Caldiera, Greater future global warming inferred from Earth’s recent energy budget RCS 3.7C
2011 NAP National Academy Science (US) Understanding Earth's Deep Past Lessons for Our Climate Future Earth's deep paleo past shows a very high climate sensitivity - up to 7 to 9.6C (3 M years ago (Pliocene).
The post 2014 IPCC AR5 climate models show that climate sensitivity (2X atmospheric CO2 without feedback emissions)
is much higher than the 3C used since 1990, so past global warming projections are large under-estimates.
Jan 2020 Causes of higher climate sensitivity in CMIP6 models
10 of 27 models project >4.5C and are valid results.
18 Sept 2019 Simulation of Eocene extreme warmth and high climate sensitivity through cloud feedbacks: Sens 6C