Posted on 10/11/2005 12:46:26 PM PDT by cogitator
MIAMI — Scientists analyzing 20 years of satellite data have confirmed an atmospheric spike in a prime fuel behind global warming, according to a study in the current issue of the journal Science.
The finding is important because it used real-world readings to verify what computer simulations have predicted is happening in a key zone of Earth's atmosphere, said Brian Soden, a University of Miami scientist and lead author of the study.
It's getting wetter up there, which means it's getting hotter down here.
"This is one of the first studies to show it is increasing at the same rate as the models suggest," said Soden, an associate professor of meteorology at the University of Miami's Rosenstiel School of Marine & Atmospheric Science.
Researchers did not focus on pollutants typically blamed for global warming but on water vapor, which climatologists recognize as the "dominant greenhouse gas," Soden said.
Water vapor occurs naturally, driving the rain cycle and keeping the planet from being too cold, he said. But as global temperatures rise — from carbon-dioxide emissions from burning fossil fuel, other industrial emissions and deforestation — moisture in the atmosphere builds up with it, forming a blanket that further raises temperatures, Soden said.
"The CO2 [carbon dioxide] is the trigger," he said, "and water vapor acts as an amplifier."
Models suggest the impact is profound. Current projections predict average global temperatures rising five degrees Fahrenheit by century's end, Soden said. Without the water-vapor increase, he said, models predict a 2-degree rise.
Though the study is being published in one of the world's most-respected academic journals, Soden did not anticipate it would necessarily sway skeptics. The Bush administration, for one, has questioned global-warming theories, and critics, including some scientists, think the effect is cyclical and not linked to human activity.
"I don't think there will ever be a single study that provides the smoking gun," he said. "It is all incremental evidence that accumulates. The consensus has developed toward global warming. What role this study will play in convincing people who are still skeptical, that's impossible for me to say."
The Radiative Signature of Upper Tropospheric Moistening
"Climate models predict that the concentration of water vapor in the upper troposphere could double by the end of the century as a result of increases in greenhouse gases. Such moistening plays a key role in amplifying the rate at which the climate warms in response to anthropogenic activities but has been difficult to detect because of deficiencies in conventional observing systems. We use satellite measurements to highlight a distinct radiative signature of upper tropospheric moistening over the period 1982 to 2004. The observed moistening is accurately captured by climate model simulations and lends further credence to model projections of future global warming."
"global temperatures rising five degrees Fahrenheit by century's end"
I worry about this if I'm around at the century's end. (Hint: Not a chance).
This also explains the simultaneous increase in mean tempratures over the past 20 years on Mars as well? If the seasons are caused by the change in solar energy striking the surface of the Earth according to the relative angle, then how much of a fraction of a percentage of output of the Sun would be needed to account for Global Warming?
I don't think that the climate systems on Earth and Mars are very similar, so probably not. For one thing, the Martian atmosphere has very little water vapor.
Global warming ping
Has it been documented? Could you please point me to the source?
If there is something in the news about the weather. Hotter, Colder, Wetter, Dryer, More extreme, or Less extreme, Global Warming is guaranteed to be mentioned and will more than likely be blamed.
Global Warming is to weather what President Bush is to liberals. The thing to blame for all the problems.
I just got a papercut. Damned Global Warming!!
It is also the gas emitted in volume by hydrogen powered cars. How is this going to help?
All we need is some cost effective technology to precipitate water vapor from the atmosphere in a controlled and localized fashion. We can then manage our climate to be what we want and global warming ceases to be a vehicle for UN taxation and regulation.
The amount of H20 emitted by that process is insignificant to the amount of water vapor in the atmosphere, which is largely determined by the temperature of the atmosphere.
This article may help make it clearer; it helped me understand it better:
It never used to rain in Seattle.
It's very interesting the spin in this article or in the study. They did not study the green house gases blamed for global warming. They studied water vapor. They admit that with the increase in temperature there would be an increase in vapor. I don't think it's disputed that there has been a slight warming over the past few decades, so naturally you would expect more water vapor, so this study simply confirms this. How the "so called" greenhouse gases and global warming theory is intertwined and supported by this study, I have know idea. Of course the skeptics aren't going to be swayed since this study absolutely proved nothing as to the greenhouse gas and global warming theory. The study simply supports the theory (and pretty much accepted) that the earth has warmed, but does not point to a cause.
So here's what we do:
1. Build a big nuclear power plant in the Nevada desert.
2. Hook it up to power the mother of all dehumidifiers. I envision a dehumidifier a few hundred feet high that removes thousands of gallons of water from the atmosphere. Even desert air has some water vapor.
3. Create a man-made river from the dehumidifier to the Las Vegas water supply.
We get a greenhouse gas out of the atmosphere. We can stop worrying about where Vegas will gets its water in twenty years.
4. Repeat for every other desert city in the world in nations that can be trusted with nuclear power plants.
Follow the link in post 11. Quick summary: greenhouse gases provide a radiative forcing, causing an increase in the temperature of the atmosphere, and the water vapor content (relative humidity) is a feedback, causing a further increase in the atmospheric temperature. The feedback (positive in this case) augments the effect of the increased radiative forcing. There are other possible negative feedbacks, such as increased cloud cover, which would reflect more solar energy back to space.
Somewhere -- and I'm not going to figure out where now -- I read about passive systems that could do the same thing. Imagine fog/dew catching on a large scale.
Ping.
And if the hydrogen is extracted from water, then burning the hydrogen wouldn't add any more water to the system; it would just return the water back.
You cover a lot of subjects. My personal view is that nuclear power can be used with relative safety, augmented by as much renewable power as can be deployed where it works. Nuke power can be used for production of biofuels (I'm particularly attracted to the feasibility and economics of switchgrass -- biofuels don't cause an increase in greenhouse gases). Combine that with a concerted effort to increase efficiency in a lot of different processes -- which we ought to be advocating the government to do in the interests of national security -- and we can substantially decrease our fossil fuel dependence.
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