by Nic Lewis
The four constraints that Caldwell assessed as credible.
by Nic Lewis
Emergent constraints on climate sensitivity: their nature and assessment of validity.
Posted in Sensitivity & feedbacks
by Frank Bosse
A few days ago a paper (Sato et al) dealing with some aspects of the “Aerosol Cloud Interactions”, (ACI, also called “aerosol indirect effects”) was released. It bolsters the conclusions of earlier papers: the effective radiative forcing from ACI (ERFaci) is smaller than thought, perhaps near zero .
Posted in Sensitivity & feedbacks
by Javier
Summary: Modern Global Warming has been taking place for the past 300 years. It is the last of several multi-century warming periods that have happened during the Neoglacial cooling of the past 3000 years. Analysis of Holocene climate cycles shows that the period 1600-2100 AD should be a period of warming. The evidence suggests that Modern Global Warming is within Holocene variability, but the cryosphere displays a non-cyclical retreat that appears to have undone thousands of years of Neoglacial ice advance. The last 70 out of 300 years of Modern Global Warming are characterized by human-caused, extremely unusual, rapidly increasing CO2 levels. In stark contrast with this rapidly accelerating anthropogenic forcing, global temperature and sea level appear to have continued their rising trend with no perceptible evidence of added acceleration. The evidence supports a higher sensitivity to CO2 in the cryosphere, suggesting a negative feedback by H2O, that prevents CO2 from having the same effect elsewhere.
Posted in Attribution, Sensitivity & feedbacks
by Nic Lewis
Recently a new model-based paper on climate sensitivity was published by Kate Marvel, Gavin Schmidt and others, titled ‘Internal variability and disequilibrium confound estimates of climate sensitivity from observations’.[1]
Posted in Sensitivity & feedbacks
by Nic Lewis
My reply to Patrick Brown’s response to my my comments on his Nature article.
Posted in Sensitivity & feedbacks
by Patrick Brown
A response to Nic Lewis’ post A closer look shows global warming will not be greater than we thought.
Posted in Sensitivity & feedbacks
by Nic Lewis
A critique of a recent paper by Brown and Caldeira published in Nature that predicted greater than expected global warming.
Posted in climate models, Sensitivity & feedbacks
by Frank Bosse
Increasing evidence of small aerosol forcing supports the importance of internal variability in explaining inter hemispheric differences in temperature variability.
Posted in Sensitivity & feedbacks
by Nic Lewis
A new paper in Science Advances by Cristian Proistosescu and Peter Huybers (hereafter PH17) claims that accounting for the decline in feedback strength over time that occurs in most CMIP5 coupled global climate models (GCMs), brings observationally-based climate sensitivity estimates from historical records into line with model-derived estimates.
Posted in Sensitivity & feedbacks
by Nic Lewis
Kyle Armour has a new paper out in Nature Climate Change: “Energy budget constraints on climate sensitivity in light of inconstant climate feedbacks”.
Posted in Sensitivity & feedbacks
by Judith Curry
The Social Cost of Carbon is emerging as a major source of contention in the Trump Administration.
Posted in Economics, Policy, Sensitivity & feedbacks
by Frank Bosse
Towards eliminating multi-decadal natural oscillations in determination of the Transient Climate Response (TCR) to CO2.
Continue reading
Posted in Sensitivity & feedbacks
by Frank Bosse
Separating out the impacts of internal variability on evaluations of TCR.
by Donald Rapp
In a recent paper, Ellis and Palmer (2016) proposed that deposition of dust on giant ice sheets, thus reducing their albedo, was a principal factor in the termination of Ice Ages over the past 800 kyrs.
Posted in Attribution, Sensitivity & feedbacks
by Guido van der Werf
The 200% increase in fossil fuel emissions Murry Salby claims is about 20% in reality, and the constant CO2 growth rate he found actually increased by roughly 20% as well over the same time period.
Posted in Sensitivity & feedbacks
by Nic Lewis
In a recently published paper (REA16),[i] Mark Richardson et al. claim that recent observation-based energy budget estimates of the Earth’s transient climate response (TCR) are biased substantially low, with the true value some 24% higher.
Posted in Sensitivity & feedbacks
by Judith Curry
A new paper purports to have resolved the discrepancy between climate response estimates from global climate models versus energy budget models.
Posted in Sensitivity & feedbacks
by Judith Curry
Some new analyses are shedding some light on deficiencies in the approach to estimate the social cost of carbon.
by Judith Curry
Four new papers remind us of the very large uncertainties surrounding cloud-climate feedbacks.
Posted in Sensitivity & feedbacks
by Greg Goodman
Inappropriate use of linear regression can produce spurious and significantly low estimations of the true slope of a linear relationship if both variables have significant measurement error or other perturbing factors. This is precisely the case when attempting to regress modelled or observed radiative flux against surface temperatures in order to estimate sensitivity of the climate system. Continue reading
Posted in Sensitivity & feedbacks
by Greg Goodman
Several of the major datasets that claim to represent “global average surface temperature” are directly or effectively averaging land air temperatures with sea surface temperatures.