Global Warming and solar varability

[sponger]

Since its a quiet week I thought I would add another log on the GW fire. The link below was written by John Daly, a global warming skeptic. The research he sites offers some insight to the theory that the midevil warm period and mini ice age were regional not global events and discusses the suns impact on climate.


http://www.john-daly.com/hockey/hockey.htm

Jim Hughes, I would love to hear your thoughts on ho! accurate pre 1960 solar output measurements are!

[Aslkahuna]

They use Carbon Isotopic analysis to infer levels of Solar activity since the distribution of the isotopes is sensitive to what happens Geophysically as a result of increased and decreased Solar activity levels. Additionally, studies have been done on Solar type stars that exhibit activity cycles similar to our Sun's and from that they have been able to determine that such periods of enhanced and depressed activity are common among Main Sequence stars of the same Spectral Class as the Sun. My measuring the Calcium K output variability, they can then infer just how much variability in Solar Luminosity we can expect from the Sun during either magnetic minima or maxima.

Steve

[gigabite]

Mister Steve, your honor sir, the great debate that solar luminosity and irradiance are counter points doesn’t seem to enter your approach to this topic.

Total solar irradiance means that the solar flux has been integrated over all wavelengths to include the contributions from ultraviolet, visible, and infrared radiation. Where it seems evident that luminosity does cusp at the solar max, irradiance is increasing over the span of time.

http://ks.water.usgs.gov/Kansas/waterda ... alway.html

[Cowhide]

Something tells me we are in for a tailspin real soon.

[sponger]

Cowhide, its a pretty picture, but it only shows the #1 offender, not total output. Co2 is a small % of total green house gasses (most is water vapor)

[sponger]

Gigabite, great link. Seems to show a strong inverse correlation between total solar irradiance and glacial mass. It also shows strong overall increase since 1980.

[x-y-no]

Cowhide, its a pretty picture, but it only shows the #1 offender, not total output. Co2 is a small % of total green house gasses (most is water vapor)

Yes, water vapor (and clouds) account for the majority of the greenhouse effect (although the direct effect of carbon dioxide is not inconsiderable - somewhere around 10% to 20% of the total effect).

But water vapor is a feedback, not a forcing. The reason for this is that if you pump a large amount of water into the atmosphere, it will rapidly precipitate out. Similarly, if one could somehow remove all the water from the atmosphere, it would rapidly be replenished by evaporation from the surface. By rapidly, I mean returning to equilibrium within a few weeks at most.

By contrast, GHGs like carbon dioxide and CFCs have atmospheric lifetimes of many decades or even centuries, and even methane has an atmospheric lifetime approaching a decade.