In a recent post on his web site, Dr. James Hansen wrote a piece entitled "Strategies & Sundance Kid
" he started with the usual and a oft repeated claim of imminent tipping points leading to run-away heating and melting of the Arctic ice caps. The story goes according to Hansen, "Our global climate is nearing tipping points. Changes are beginning to appear, and there is a potential for rapid changes with effects that would be irreversible – if we do not promptly slow fossil fuel emissions during the next few decades. Tipping points are fed by amplifying feedbacks. As Arctic sea ice melts, the darker ocean absorbs more sunlight and speeds melting. As tundra melts, methane a strong greenhouse gas, is released, causing more warming.
My response, "This paper even includes at least one reference to one of your papers and lists 4 scientists as authors from Columbia University, where Dr. Hansen is an Adjunct Professor: Earth and Environmental Sciences. It demonstrates that cloud cover is increased with melting Arctic ice completely offsetting the albedo effect and even a bit more. So, again, the Earth shows another of it's feedbacks to counter physical changes.
Hansen then wrote: "As species are pressured and exterminated by shifting climate zones, ecosystems can collapse, destroying more species." And to address the second part I responded: "No positive feeedback, no destroyed species.
You can read the rest of the reference paper yourself as it extols the virtues of government actions to control what we breathe outbut without the tipping points there is no reason to control anything. So this is where I would like to concentrate my efforts. The paper, The Influence of Cloud and Surface Properties on the Arctic Ocean Shortwave Radiation Budget in Coupled Models
,IRINA V. GORODETSKAYA et al is really about "the impact of Arctic sea ice concentrations, surface albedo, cloud fraction and cloud ice and liquid water." according to the paper. Although the intent of the paper is to compare the outputs of the models, there was the intrinsically necessary comparison to reality.
The paper goes on to say, "Using satellite data of the 1982–98 period in the area north of 60°N, Wang and Key (2003) found a significant negative trend in the surface albedo in the Arctic during the spring and summer. The authors claim that the expected enhancement of the surface net radiation imbalance was reduced or even cancelled out by a concurrent increase in cloud amount, as well as more frequent occurrence of liquid phase clouds
. Although the significance of the summer cloud amount trend is disputable due to its small magnitude and short time period,the cloud amount trends in spring are significant,especially over ocean areas (Schweiger 2004). The end of spring and summer surface radiation budget determines the rate of sea ice melt. Thus misrepresentation of cloud properties (including both the cloud amount and cloud particle phase) in models will result in an erroneous estimate of surface net radiation balance and therefore an incorrect sea ice mass budget."
Although there is some reservation here, the data shows that the change in albedo from the ice loss may be cancelled out by the cloud formation in the liquid phase.
From the paper we read, "In reality, changes in the surface SW radiation budget due to the ice linked to cloud effects (Curry et al. 1996, 1993; Randall et al. 1994; Vavrus 2004). Atmospheric transmittanceand solar elevation determine the amount of radiation reaching the surface, part of which is absorbed by the surface, depending on surface albedo. Atmospheric transmittance in turn strongly depends on the cloud water path and the cloud phase. Water droplets are more effective in reflecting and absorbing solar radiation than nonspherical, typically larger ice crystals
(Dong et al. 2001). During the Surface Heat Budget of the Arctic Ocean (SHEBA) experiment, a year-long program in the Beaufort Sea, it was found that liquid dominant mixed-phase clouds at SHEBA were very frequent throughout the year and occurred at temperaturesas low as 25 degrees."
So we find out here that the albedo (reflectivity) of water droplets in the clouds is greater than the ice and the clouds increased as the ice melted or moved away. Sounds like a hint that the tipping-point is in trouble already.
In the conclusion the paper cites "The predicted substantial decrease in Arctic summer sea ice concentrations during the twenty-first century may favor cloud formation, which should diminish or even cancel the ice-albedo feedback by shielding the surface
(fKato et al.2006
)" Check out this paper if you want to see a really good analysis of cloud/ice albedo comparisons.
So as I said, "No tipping point. No problem. No Cap and Tax/Trade! Man made global warming is a man-made scam. Our capitalist based economy depends on it. We do need to slap the hands of the crooks on both sides but let's not throw out the baby with the bathwater. Our standard of living and prosperity were built on fossil fuels and capitalism.
Source Link: examiner.com