New excuse #56 for the ‘pause’ in global warming: Satellites underestimate cooling from volcanic aerosols – Published in Geophysical Research Letters
New excuse #56 for the “pause” in global warming: Satellites underestimate cooling from volcanic aerosols
http://hockeyschtick.blogspot.com/2014/10/new-excuse-56-for-pause-in-global.html
A paper published today in Geophysical Research Letters states, “Understanding the cooling effect of recent volcanoes is of particular interest in the context of the post-2000 slowing of the rate of global warming” and finds “recent volcanic events are responsible for more post-2000 cooling than is implied by satellite databases” which “translates into an estimated global cooling of 0.05 to 0.12 °C.” By way of comparison, the IPCC formula claims post-2000 warming from CO2 was 5.35*ln(400/369) = 0.43W/m2 *(3C/3.7Wm-2) = 0.35C warming, which is at least three times larger than the estimated volcanic cooling found from this paper. Therefore, volcanic cooling would not be sufficient to account for the zero degrees global warming post-2000 (actually post-1996). This implies that either this new paper is incorrect regarding volcanic cooling account for the “pause,” or that the IPCC exaggerates climate sensitivity to CO2. Further, even James Hansen admits there have been no large volcanic eruptions post-2000: “Remarkably, and we will argue importantly, the airborne fraction [of man-made CO2] has declined since 2000 (figure 3) during a period without any large volcanic eruptions.” and as demonstrated by the stratospheric aerosol index of volcanic eruptions: How can volcanic aerosols explain the post-2000 “pause” without an increase of volcanic activity?Total volcanic stratospheric aerosol optical depths and implications for global climate changeD. A Ridley et al Understanding the cooling effect of recent volcanoes is of particular interest in the context of the post-2000 slowing of the rate of global warming. Satellite observations of aerosol optical depth (AOD) above 15 km have demonstrated that small-magnitude volcanic eruptions substantially perturb incoming solar radiation. Here we use lidar, AERONET and balloon-borne observations to provide evidence that currently available satellite databases neglect substantial amounts of volcanic aerosol between the tropopause and 15 km at mid to high latitudes, and therefore underestimate total radiative forcing resulting from the recent eruptions. Incorporating these estimates into a simple climate model, we determine the global volcanic aerosol forcing since 2000 to be −0.19 ± 0.09 Wm−2. This translates into an estimated global cooling of 0.05 to 0.12 °C. We conclude that recent volcanic events are responsible for more post-2000 cooling than is implied by satellite databases that neglect volcanic aerosol effects below 15 km.
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New paper finds clouds have a large net cooling effect on climate – Published in Atmospheric Research
…New paper finds global dimming & brightening were due to natural changes in cloud cover, not man-made aerosols – Published in the Journal of Geophysical Research Atmospheres
New paper finds global dimming & brightening were due to natural changes in cloud cover, not man-made aerosols
http://hockeyschtick.blogspot.com/2014/09/new-paper-finds-global-dimming.html
A new paper published in the Journal of Geophysical Research Atmospheres find that “changes in cloud cover rather than anthropogenic aerosols emissions played the major role in determining solar dimming and brightening during the last half century and that there are reasons to suppose that these findings may have wider relevance.” The wider relevance is that the well-known global dimming of the 1970’s ice age scare, followed by the global brightening to the end of the 20th century were largely if not entirely due to natural changes in cloud cover, potentially mediated by the solar/cosmic ray/cloud amplification mechanism of climate change. Further, since this study and another recent study on volcanic aerosols greatly diminish the assumed aerosol forcing on climate [cooling], this means that the role of man-made CO2 forcing on climate must also be reduced by the same amount to maintain so-called “radiative balance.” Thus, the climate sensitivity to CO2 must be much less than previously believed. The rate of warming increased by a factor of 3.8 from 1992 to 2002 corresponding to the period of “global brightening,” and was followed by global cooling and a “pause” or possible “dimming” of solar surface radiation. Related: Three new studies demonstrate climate sensitivity to CO2 is very low The cause of solar dimming and brightening at the Earth’s surface during the last half century: Evidence from measurements of sunshine durationGerald Stanhill*, Ori Achiman, Rafael Rosa and Shabtai CohenAnalysis of the Angstrom-Prescott relationship between normalized values of global radiation and sunshine duration measured during the last 50 years made at five sites with a wide range of climate and aerosol emissions showed few significant differences in atmospheric transmissivity under clear or cloud-covered skies between years when global dimming occurred and years when global brightening was measured, nor in most cases were there any significant changes in the parameters or in their relationships to annual rates of fossil fuel combustion in the surrounding 1° cells. It is concluded that at the sites studied changes in cloud cover rather than anthropogenic aerosols emissions played the major role in determining solar dimming and brightening during the last half century and that there are reasons to suppose that these findings may have wider relevance.
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Study: Man-Made Aerosol Emissions Have Helped Cool Planet
…New paper shows IPCC underestimates global cooling from man-made aerosols/clouds by factor of 27 times – Published in Science
New paper shows IPCC underestimates global cooling from man-made aerosols/clouds by factor of 27 times
http://hockeyschtick.blogspot.com/2014/06/new-paper-shows-ipcc-underestimates.html
According to a new paper published in Science, the global cooling effect of clouds nucleated by man-made aerosols since the beginning of the industrial revolution is approximately 15 watts per square meter, which is about 27 times more cooling effect than the mean estimate published in the 2014 IPCC AR5 Report:
Radiative forcing estimates from the 2014 IPCC AR5 Report show “cloud adjustments due to aerosols” since 1750 are a mean value of 0.55 watts per meter squared [+/-0.8] with level of confidence “low.”
The IPCC-admitted “low confidence” and very poor representation of clouds/aerosols in climate models effectively renders IPCC climate model projections meaningless. The model projections have also been falsified at confidence levels of 95-98%.
Aerosols that nucleate cloud formation can be from natural or man-made sources. For example, a recent paper published in Nature finds organic aerosols from pine trees may have a significant effect on cloud nucleation and cause global cooling. “Global brightening” from decreased aerosols/clouds over the past 30 years due to regulations on particulate emissions could also account for all or most of the observed warming over that period, instead of CO2.
A video in the E&E newswire article below demonstrates a dramatic cloud nucleation effect of the addition of small amounts of aerosols:
In the absence of aerosols, there can be no cloud nucleation. Scientists on an icebreaker in the Arctic demonstrated this in a video of a cup of hot tea that does not fume despite the below-zero temperatures. Then, someone flicks on a lighter and water vapor from the tea grabs aerosol particles emitted by the lighter (due to inefficient combustion) and a tiny storm appears, above the teacup.
Researchers penetrate one of the darkest mysteries of climate change — cloudsGayathri Vaidyanathan, E&E reporter ClimateWire: Friday, June 6, 2014Deadening calm fills the Horse Latitudes, where there’s ocean, sky and little else. A satellite peers down, capturing wisps of cloud, counting particles suspended in the air, measuring rainfall and monitoring weather.There is little wind. These latitudes, between 30 and 35 degrees away from the equator, are so calm that Spanish sailors in the 17th century could not move their heavily laden ships, or so the legend goes. So, the sailors dumped their cargo — horses — into the subtropical ocean and heaved on. But they left the …
New paper finds climate models simulate or predict only about 6% of altocumulus clouds – Published in Atmospheric Research
New paper finds climate models simulate or predict only about 6% of altocumulus clouds
http://hockeyschtick.blogspot.com/2014/06/new-paper-finds-climate-models-only.html
A paper published today in Atmospheric Research finds “Altocumulus clouds are important, yet climate models have difficulties in simulating and predicting these clouds” and “Approximately 93.6% of Altocumulus clouds cannot be resolved by climate models with a grid resolution of 1°.”
Thus, only 6.4% of observed altocumulus clouds are simulated or predicted by climate models. Needless to say, clouds have profound effects on Earth’s radiative balance and climate; a mere 1-2% change in global cloud cover alone can account for global warming or cooling. Among their many failings, climate models are unable to simulate clouds, ocean oscillations, solar amplification mechanisms, precipitation, sea ice, albedo, convection, etc. etc.
Spatial scales of altocumulus clouds observed with collocated CALIPSO and CloudSat measurements
Damao Zhanga, , ,
Tao Luoa,
Dong Liub,
Zhien Wang
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Climatology of Ac horizontal scale and vertical depth is presented.
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93.6% of Altocumulus clouds cannot be resolved by GCMs with a grid resolution of 1°.
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Ac scale distributions are related to their formation mechanisms.
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Ac vertical depth is impacted by CTT and environmental humidity.
Abstract
Altocumulus (Ac) clouds are important, yet climate models have difficulties in simulating and predicting these clouds, due to their small horizontal scales and thin vertical extensions. In this research, 4 years of collocated Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) lidar and CloudSat radar measurements is analyzed to study the along-track horizontal scales and vertical depths of Ac clouds. Methodology to calculate Ac along-track horizontal scale and vertical depth using collocated CALIPSO and CloudSat measurements is introduced firstly. The global mean Ac along-track horizontal scale is 40.2 km, with a standard deviation of 52.3 km. Approximately 93.6% of Altocumulus clouds cannot be resolved by climate models with a grid resolution of 1°. The global mean mixed-phase Ac vertical depth is 1.96 km, with a standard deviation of 1.10 km. Global distributions of the Ac along-track horizontal scales and vertical depths are presented and possible factors contributing to their geographical differences are analyzed. The result from this study can be used to improve Ac parameterizations in climate models and validate the model simulations.…
Satellite data shows CO2 does not control Earth’s radiative balance or climate
Satellite data shows CO2 does not control Earth’s radiative balance or climate
http://hockeyschtick.blogspot.com/2014/04/satellite-data-shows-co2-does-not.html
Dr. Roy Spencer has an interesting post today analyzing several satellite datasets, which suggest “some portion of recent warming was simply due to a natural decrease in cloud cover.”Dr. Spencer also finds an independent method of determining Earth’s radiative fluxes [fig 6 below], since “radiative fluxes are so important (e.g. being the basis for global warming theory) that any independent means of estimating them are worth looking into.” “Be careful in interpreting the estimated radiative fluxes in Fig. 6 because they could have an offset. Since the anomalies I compute (by definition) sum to zero over the entire time series, that means the total time-integrated radiative energy flux also sums to zero. So, while the graph in Fig. 6 suggests energy loss by the global oceans over the last 5 years, it could be the whole curve needs to be shifted upward. There is no way to know.”I have overlaid the CO2 forcing from increased CO2 levels since 1987 as the red line in Dr. Spencer’s Fig. 6 below, based upon the IPCC/Myhre formula for CO2 forcing due to the change in CO2 levels of 349.16 ppm in 1987 to 400 ppm today,
5.35*ln(400/349.16)=0.73 W/m2
which clearly illustrates a disconnect between CO2 levels and net radiative flux, and demonstrates CO2 radiative forcing is not the so-called climate “control knob.”
However, all IPCC models are based upon the IPCC/Myhre formula for CO2 radiative forcing, and despite the complexity of the models, the global warming predictions essentially follow this simple formula 1:1:
You don’t even need a climate model to show what climate models predict – projections are based upon a single independent variable – CO2
Thus explaining why the models have been falsified at confidence levels exceeding 98%.
SSM/I Global Ocean Product Update: Increasing clouds with a chance of cooling
by Roy W. Spencer, Ph. D.
My research field of satellite passive microwave remote sensing took off like a rocket (pun intended) when the first Special Sensor Microwave/Imager (SSM/I, built by Hughes Aircraft) was launched in mid-1987 on the DoD series of weather satellites (DMSP).
We SO anticipated that first instrument…good calibration, and high frequency channels to estimate precipitation over land. The previous NASA instruments (ESMR-5, -6, and SMMR) were a good start, but had limited channel selection and less than optimal calibration strategies.
The SSM/I instrument series …
Settled Science: New paper finds effect of man on climate is ‘highly uncertain’ – Published in Science
One of several reasons for this high uncertainty is the complexity of determining the cooling effects of aerosols, which reflect sunlight back to space, and can also seed cloud formation. According to the authors, “Aerosols counteract part of the warming effects of greenhouse gases, mostly by increasing the amount of sunlight reflected back to space. However, the ways in which aerosols affect climate through their interaction with clouds are complex and incompletely captured by climate models.
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