Main Question or Discussion Point
Anyone have it? How can I get it?
:rofl: Just for your amusement I thought I'd show you the balls up that '2000 leading scientists' made in their recent IPCC report thingy.
Check out the attachment, this is the table from the recent IPCC summary except I've annotated it to highlight its flaws.
1. 2,000 leading scientists cannot add. Add up the separate contributions to global sea level rise (that they have given themselves) and you will see that it does not equal the total rise in sea level (that they also give themselves).
2. They say that the sea level is rising by 30 cm/century, actually they're wrong, it's more like 3 cm/century.
And just for the record it's not just me that's saying this, the mistakes were pointed out to me by an esteemed professor.
The IPCC places CO2 levels @ 379 ppm as of 2005*What is the 'Pre-Saturation Point'(possibly 'sublimation point') of Carbon PPM build-up in our Atmosphere?
*Someone wrote that we are between 360-380 PPM, and although I cannot say how I came up with this number, I think '358' is a very critical number that predicts a range barrier that we should maintain below.
*There must be a 'Fail Safe' Point of which we cannot pass, and obviously we do not want to reach 'Saturation', for then our BioSphere would collapse.
Excellent point; I'm trying to figure that out myself....There must be a 'Fail Safe' Point of which we cannot pass, and obviously we do not want to reach 'Saturation', for then our BioSphere would collapse...
I'm not a scientist, but if we correlate this 'PPM' number with the reason we are presently witnessing our glaciers breaking apart/melting, and our oceans dying the 'slow death'(per se), and the extinction rate of some species(never seen before in our life time), I'd say the data is overwhelmingly convincing.The IPCC places CO2 levels @ 379 ppm as of 2005
Don't be so frightened of CO2 levels, i is not that significant, as I can show you in the Vostock ice core data where CO2 levels hovered between 260ppm and 280 pmm for 8k years while temps plummeted over 6 degrees celcius !
I think we should curb burning fossile fuels, but not because of so called "global warming". I call it weather redistribution.
B.T.W. anyone try linking the changing magnetic fields of the earth with this "weather redistribution" ?
Excellent point; I'm trying to figure that out myself.
The IPCC report summary implies the
"fail safe" point may be about 450 ppm (vs today's approx 379 ppm) atmospheric CO2. They don't actually say "safe threshold", but that's the lowest level mentioned in the report summary.
The IPCC says to stay under this limit requires reduction of cumulative carbon emissions over the remaining 21st century from about 670 gigatons carbon to about 490. I think they made a simple math error in failing to account for compound annual increases in the 1st number (which should really be about 1900 GtC), further info here:
However let's assume the 2nd number is valid -- limiting cumulative carbon emissions over the remaining 21st century to 490 GtC is required to limit atmospheric CO2 to 450 ppm, which in turn limits global warming.
But -- there's a significant discrepancy between the 490 GtC plus what we actually observe. 490 GtC over 93 yrs averages at 5.2 GtC/yr, which is WAY above what the safe threshold is, according to IPCC and other numbers.
E.g, according to the IPCC, global warming was well underway by 1945, caused by anthropogenic CO2 emissions. However at that point emissions were only about 1.5 GtC/yr:
So it just doesn't add up. If the annual temperature increases up to mid-20th century are significantly caused by anthropogenic CO2, this implies the safe upper emissions limit is much lower than the IPCC number of 490 GtC cumulative over the remaining 21st century (5.2 GtC/yr average).
That in turn implies either (a) much greater reductions are needed or (b) some kind of mistake in the calculations were made. Both items can't be true: that global warming was happening at 1.5 GtC/yr, yet reducing emissions to an average of 5.2 GtC/yr is safe.
The amount of water vapor released from combustion by human activity is insignificant compared to the amount evaporated every day. However, a more important factor is the capacity for the atmosphere to hold water vapor. Since increasing CO2 levels allow the atmosphere to hold more water vapor, climate sensitivity includes the warming from water vapor.Since water vapour is released on the combustion of alcohols (including methanol and ethanol) and alkanes (including methane, propane, gasoline and diesel fuels), but not coal, and by transpiration in plants in forests and crops, efforts to mitigate climate change by reducing human-produced water vapour would run in exactly the opposite direction to efforts to reduce climate change by controlling CO2 alone.
These claims are false.The accurate value for climate sensitivity is 0.277 K/(W/m^2), which is 3 times smaller than the generally accepted value of 0.8 K/(W/m^2). Thus the climate change on doubling CO2 from 300 ppm to 600 ppm will be 1.0 degree, not 3 degrees. Because the IPCC data show that doubling CO2 will not double absorption of infrared radiation, the Beer-Lambert law is not being followed, because of diminishing returns after more-than-50% absorption. Thus further doublings of CO2 to the point of suffocating levels can only result in a fraction of a degree increase. Therefore global warming by CO2 increases has been wildly overestimated. The same IPCC data show that water vapour is 1.5 times as important as CO2 as a greenhouse gas, and it still seems to follow the Beer-Lambert law (doubling the concentration doubles the absorption). Thus climate changes are more sensitive to changes in water vapour than to CO2. Since water vapour is released on the combustion of alcohols (including methanol and ethanol) and alkanes (including methane, propane, gasoline and diesel fuels), but not coal, and by transpiration in plants in forests and crops, efforts to mitigate climate change by reducing human-produced water vapour would run in exactly the opposite direction to efforts to reduce climate change by controlling CO2 alone. However, the formation of clouds from increased water vapour would provide a negative-feedback mechanism which is difficult to model accurately.
Roger has confused the notion of climate sensitivity with the notion of Plank response. Neither value is known with three figures of accuracy.The accurate value for climate sensitivity is 0.277 K/(W/m^2), which is 3 times smaller than the generally accepted value of 0.8 K/(W/m^2).
Now, repeating my remark,Water vapour in the atmosphere
Water vapour is indeed the strongest greenhouse gas in the atmosphere. The interactions of gases is not simple, but in general I would say water is at least twice as important as carbon dioxide for the Earth's greenhouse effect. 1.5 times seems an underestimate of its importance.
The major point about water vapour is that it cycles through the atmosphere so quickly. Enormous volumes of water evaporate into the atmosphere and precipitate out again every day. The total water content is determined largely by temperature. As temperature rises, you get more water vapour (higher specific humidity), as relative humidity remains about the same or even reduces a bit. If you add a lot of water into the atmosphere, it rains out again in very short order, to restore the natural equilibrium for humidity.
Hence human emissions of water into the atmosphere don't have much effect on the total water vapour content. The best way to have a significant effect on water vapour is to somehow raise temperatures. This is why water vapour is treated as a "feedback", and carbon dioxide as a "forcing". Added carbon dioxide remains in the atmosphere a long time, and contributes to a stronger greenhouse effect and higher temperatures. This tends to raise specific humidity, which increases water in the atmosphere as well, and that makes the greenhouse effect stronger again. There are many complexities with the feedbacks, discussed in the reference Bony et al (2006) cited above. The point is that it is a feedback, because humidity is so strongly influenced by temperature, rather than by anthropogenic emissions.
Did somebody do the paperwork here, how high is the energy bill? And is global warming paying for that? For getting all that extra water in the atmosphere?It would also be interesting to calculate the energy required versus energy available to evoporate the additional water vapor required to keep that feedback going.
All the energy that matters ultimately comes from the Sun.Did somebody do the paperwork here, how high is the energy bill? And is global warming paying for that? For getting all that extra water in the atmosphere?
We've had this discussion long ago I vaguely remember.I just would like to see how many W/m2 of energy is required to sustain the higher evaporation rate, associated with keeping relative humidities more or less constant with higher temperatures as proposed for the positive feedback.
The total energy is the same, no matter what feedbacks are involved. It is the energy from the Sun. We get about 342 W/m2, of which about 30% is reflected, leading 240 W/m2 absorbed into the Earth. All the energy must be radiated again.I just would like to see how many W/m2 of energy is required to sustain the higher evaporation rate, associated with keeping relative humidities more or less constant with higher temperatures as proposed for the positive feedback.
I am having a hard time sorting out what you want.Obviously that additional energy has to come from the increased IR back radiation and it also is not available to warm the surface.
I did not encounter calculations for that so far, so can you shown them? and transparantly of course, like independently reproduceable.
Of course we could try some ball park figures for a very rough order of magnitude estimate.
Exactly, but where is that condensation happening? and what happens to that energy after condensation, heating the earth surface? or is it lost in space for a big part?We've had this discussion long ago I vaguely remember.
There is no constant energy flux necessary to do this, as what is "lost" at evaporation is also "gained back" at condensation.