As this sinking air mass weighs on the marine layer, the latter compresses into a thin layer with a relatively
high concentration of water vapor.
The convective heat / mass transfer due to water dwarfs any radiative forcing; besides — just on optical depth alone, any re-radiated LWIR from atmospheric CO2 would be IMMEDIATELY absorbed by the much
higher concentration of water vapor in the atmosphere (aka clouds!)
Not exact matches
Greenhouse gases (which prevent dispersal
of heat generated by the planet's surface, after this receiving solar radiation)
of higher concentration on Earth are carbon dioxide (CO2), methane (CH 4), nitrous oxide (N2O), Compounds
of chlorofluorocarbon (CFC) and
water vapor (H2O).
[1] CO2 absorbs IR, is the main GHG, human emissions are increasing its
concentration in the atmosphere, raising temperatures globally; the second GHG,
water vapor, exists in equilibrium with
water / ice, would precipitate out if not for the CO2, so acts as a feedback; since the oceans cover so much
of the planet,
water is a large positive feedback; melting snow and ice as the atmosphere warms decreases albedo, another positive feedback, biased toward the poles, which gives larger polar warming than the global average; decreasing the temperature gradient from the equator to the poles is reducing the driving forces for the jetstream; the jetstream's meanders are increasing in amplitude and slowing, just like the lower Missippi River where its driving gradient decreases; the larger slower meanders increase the amplitude and duration
of blocking
highs, increasing drought and extreme temperatures — and 30,000 + Europeans and 5,000 plus Russians die, and the US corn crop, Russian wheat crop, and Aussie wildland fire protection fails — or extreme rainfall floods the US, France, Pakistan, Thailand (driving up prices for disk drives — hows that for unexpected adverse impacts from AGW?)
1) Even though CO2
concentrations in the atmosphere has gone up by 30 % over the last 200 years or so (compared to being stable for 400 000), I have a hard time to comprehend how an increase from 0.028 % to 0.038 %
of CO2 by volume can have any effect on the thermal mass
of the atmosphere considering that
water vapor by volume is 50x greater and has
higher thermal coefficients.
(In the global time average, diffusion
of latent heat is in the same direction as sensible heat transport, but latent heat will tend to flow from
higher to lower
concentrations of water vapor (or equilibrium
vapor pressure at the liquid / solid
water surface), and regionally / locally, conditions can arise where the latent heat and sensible heat fluxes are oppositely directed.)
But the boiling point
of heavy
water, as well as heavy oxygen
water (H2O ^ 18 rather than H2O ^ 16) are
higher than that
of normal
water, and are found in
water vapor in the atmosphere at lower
concentrations when the global temperature is low.
An observed consequence
of higher water vapor concentrations is the increased frequency
of intense precipitation events, mainly over land areas.
«What our study shows is that observed
water vapor concentrations are
high enough and temperatures are low enough over the U.S. in summertime to initiate the chemistry that is known to lead to ozone losses,» said Harvard atmospheric scientist David Wilmouth, one
of the paper's co-authors, in an email.
AGW is a hypothesis that makes sense, namely: — GHGs absorb outgoing radiation, thereby contributing to warming (GH theory)-- CO2 is a GHG (as is
water vapor plus some minor GHGs)-- CO2
concentrations have risen (mostly since measurements started in Mauna Loa in 1959)-- global temperature has risen since 1850 (in ~ 30 - year warming cycles with ~ 30 - year cycles
of slight cooling in between)-- humans emit CO2 and other GHGs — ergo, human GHG emissions have very likely been a major contributor to
higher GHG
concentrations, very likely contributing to the observed warming
Cloud condensation nuclei: Aerosol particles that provide a platform for the condensation
of water vapor, resulting in clouds with
higher droplet
concentrations and increased albedo.
One consequence
of higher water vapor concentrations is more frequent, intense precipitation.
They use the longer time series that is available with the NCEP
water vapor data set with reservations, but at the same time attempting to use that part
of the data set that has been considered by other authors to be more reliable (at
higher water vapor concentrations) and for time periods considered more reliable.