Sentences with phrase «feedback climate sensitivity over»
The average fast - feedback climate sensitivity over the LGM — Holocene range of climate states can be assessed by comparing estimated global temperature change and climate forcing change between those two climate states [3,86].
http://rsta.royalsocietypublishing.org/ Not exact matches
Using information from pre-historic climate archives, Zeebe calculated how slow climate feedbacks (land ice, vegetation, etc.) and climate sensitivity may evolve over time.
What about the feedbacks that are not normally well represented by ECS and normally fall into the Earth System Climate Sensitivity, stuff like the Arctic Ice cover, which now has trends over decades closer to what was seen on centuries in paleoclimate:
In short, whatever the initial climate sensitivity is to a doubling of CO2, I just can't buy off on this positive feedback loop idea that says that temperatures are going to spin out of control once we pass over some «tipping point» that only seems to exists in some scientist's theoretical model.
It is possible that effective climate sensitivity increases over time (ignoring, as for equilibrium sensitivity, ice sheet and other slow feedbacks), but there is currently no model - independent reason to think that it does so.
Therefore, estimating equilibrium climate sensitivity based on measurements of a climate that's out of equilibrium requires making some significant assumptions, for example that feedbacks will remain constant over time.
«The team emphasized that clouds are particularly sensitive to subtle differences in surface warming patterns, and researchers must carefully account for such pattern effects when making inferences about cloud feedback and climate sensitivity from observations over short time periods.»
The sensitivity he then derives is projected back using the 0.8 deg C warming over the 20th C. However, this is ludicrous — the sensitivity in the recent period can't be more than say, 1 ppmv per 0.1 deg C. Projected back you would have say a 10 ppmv (max) change over the 20th C. Paleo - climate constraints demonstrate that CC feedback even on really long time scales is not more than 100 ppmv / 6 deg C (i.e. 16 ppmv / deg C), and over shorter time periods (i.e. Frank et al, 2010) it is more like 10 ppmv / deg C. Salby's sensitivity appears to be 10 times too large.
Using measured amounts of GHGs during the past 800000 years of glacial — interglacial climate oscillations and surface albedo inferred from sea - level data, we show that a single empirical «fast - feedback» climate sensitivity can account well for the global temperature change over that range of climate states.
There are multiple, conflicting lines of evidence in climate sensitivity, and nothing has really ruled out the possibility of a tail that extends over 4C for a doubling, and that's without even allowing for some kind of carbon cycle feedback that causes land to turn from a sink to a source of CO2.
Gavin writes «Paleo - climate constraints demonstrate that CC feedback even on really long time scales is not more than 100 ppmv / 6 deg C (i.e. 16 ppmv / deg C), and over shorter time periods (i.e. Frank et al, 2010) it is more like 10 ppmv / deg C. Salby's sensitivity appears to be 10 times too large.»
Recently there have been some studies and comments by a few climate scientists that based on the slowed global surface warming over the past decade, estimates of the Earth's overall equilibrium climate sensitivity (the total amount of global surface warming in response to the increased greenhouse effect from a doubling of atmospheric CO2, including amplifying and dampening feedbacks) may be a bit too high.
There is no missing heat in this model, but there is an acknowledgement that the negative feedback on the lapse rate is an important factor that suppresses a high climate sensitivity over the ocean.
I am particularly grateful to Professors David Douglass and Robert Knox for having patiently answered many questions over several weeks, and for having allowed me to present a seminar on some of these ideas to a challenging audience in the Physics Faculty at Rochester University, New York; to Dr. David Evans for his assistance with temperature feedbacks; to Professor Felix Fitzroy of the University of St. Andrews for some vigorous discussions; to Professor Larry Gould and Dr. Walter Harrison for having given me the opportunity to present some of the data and conclusions on radiative transfer and climate sensitivity at a kindly - received public lecture at Hartford University, Connecticut; to Dr. Joanna Haigh of Imperial College, London, for having supplied a crucial piece of the argument; to Professor Richard Lindzen of the Massachusetts Institute of Technology for his lecture - notes and advice on the implications of the absence of the tropical mid-troposphere «hot - spot» for climate sensitivity; to Dr. Willie Soon of the Harvard Center for Astrophysics for having given much useful advice and for having traced several papers that were not easily obtained; and to Dr. Roy Spencer of the University of Alabama at Huntsville for having answered several questions in connection with satellite data.