Articles Tagged "Water Vapour"

Abstract

This article is a response to a claim about the positive feedback of water vapor on the total emissivity of the carbon dioxide related to the overlap of absorption-emission bands. I have taken into consideration the total altitude of the atmosphere, answering to another erroneous claim on the sense of including the total path length of the irradiance from the surface. In addition, I have calculated the effect of the carbon dioxide in the temperature of the atmosphere of Mars for demystifying the concept of the carbon dioxide as a warming gas.

Introduction

When I presented my article on the Total Emissivity of the Carbon Dioxide and its Effect on the Atmospheric temperature, the main criticisms were on the sense that I had not considered the overlapping absorption and emission bands of the carbon dioxide and the water vapor, as well as the length that I had introduced for making my calculations which, according to those criticisms, it should be 7000 m, which is the altitude of the atmosphere at which the proportion of the gases in the air mixture is more or less uniform, instead 1 m.

I have acceded to those claims and introduced the altitude of 7000 m in the algorithms for calculating the total emissivity of the mixture of water vapor and carbon dioxide in the atmosphere.

In the other hand, there were claims against my decision to obtain the total emissivity of the carbon dioxide alone, when they claimed that the water vapor worked like a positive feedback that enhanced the total emissivity of the carbon dioxide in the region of the emissive spectrum where the emission bands of the carbon dioxide and the water vapor overlaps. I assented to make the calculi for obtaining the amount of total emissivity that the water vapor causes on the total emissivity of the carbon dioxide, precisely there, where the emission bands overlap.

CLICK to download PDF from Nasif S. Nahle

With CO2 driven global warming becoming more discredited by new scientific evidence every day, the world's meddling climate regulators are casting about for a new gas to demonize. Last year the US Environmental Protection Agency was reportedly thinking of even classifying water vapor as a pollutant, due to its central role in global warming. Because water vapor is the dominant greenhouse gas in the atmosphere, accounting for the majority of the Earth's natural greenhouse effect, water vapor emissions during human activities—such as the processing and burning of fossil fuels—are again coming under increasing scrutiny by government regulators.

Recent research has shown that water vapor, gaseous H2O, plays an important part in regulating Earth's temperature. It has long been known that H2O is responsible for the majority of “greenhouse” warming. In fact, calculations show that removal of all greenhouse gases, leaving only water vapor, would decrease the absorption of infrared energy re-radiated by Earth's surface by only 34 percent. While water vapor in the atmosphere is highly variable, ranging from only trace amounts to as much as 4%, the overall average amount of H2O has been rising in recent decades.

According to a PNAS report by B, D. Santer et al. the recent increase in water vapor is primarily due to human-caused increases in GHGs and not to solar forcing or volcanic eruptions. Satellites have observed an increase in atmospheric water vapor of about 0.41 kg/m2 per decade since 1988. Observations show the increase in water vapor is around 6 to 7.5% per degree Celsius warming of the lower atmosphere. The study described the research this way:

Results from current climate models indicate that water vapor increases of this magnitude cannot be explained by climate noise alone. In a formal detection and attribution analysis using the pooled results from 22 different climate models, the simulated "fingerprint" pattern of anthropogenically caused changes in water vapor is identifiable with high statistical confidence in the SSM/I data. Experiments in which forcing factors are varied individually suggest that this fifingerprint ‘‘match’’ is primarily due to human-caused increases in greenhouse gases and not to solar forcing or recovery from the eruption of Mount Pinatubo. Our findings provide preliminary evidence of an emerging anthropogenic signal in the moisture content of earth’s atmosphere.

Click source to read FULL report by Doug L. Hoffman

A new report in Science underscores what many scientists have been saying for years, it's water vapor, not CO2, that has been driving global temperature changes in recent decades. Stratospheric water vapor concentrations decreased by about 10% after the year 2000, slowing the rate of global surface temperature increase over the past 10 years. It also seems likely that water vapor in the stratosphere increased between 1980 and 2000, causing surface temperatures to warm by an extra 30% during the 1990s. These findings show that stratospheric water vapor represents an important driver of decadal global surface climate change, yet the IPCC crowd continues to focus on CO2.

The new report, “Contributions of Stratospheric Water Vapor to Decadal Changes in the Rate of Global Warming,” by Susan Solomon et al. states that from 2000 to 2009 diminished water vapor levels in the upper atmosphere depressed global warming by about 25% compared to that which would have occurred due only to carbon dioxide and other greenhouse gases. More limited data suggest that stratospheric water vapor probably increased between 1980 and 2000, which would have enhanced the decadal rate of surface warming during the 1990s by about 30% compared to estimates neglecting this change.

Click source to read FULL report by Doug L. Hoffman

Climate scientists have overlooked a major cause of global warming and cooling, a new study reveals today.

American researchers have discovered that the amount of water high in the atmosphere is far more influential on world temperatures than previously thought.

Although the findings do not challenge the theory of man-made global warming, they help explain why temperatures can rise and fall so dramatically from decade to decade.

Using satellite infrared spectroscopy to provide an almost global perspective on the near-surface distribution of water vapor, a new report in Science has identified more water vapor inaccuracies in current general circulation models (GCM), the computer programs used by climate scientists to predict future climate trends. The researchers uncovered anomalies in the Hadley circulation and its misrepresentation in GCM. Looks like climate theory and the IPCC's error ridden models are in for another round of corrections.

Following hot on the heals of my last column that reviewed a study on water vapor latent heat transfer and climate modeling modeling (see “Climate Models Blown Away By Water Vapor”), a new report has identified even more places where current climate models get atmospheric circulation and the hydrological cycle wrong. Christian Frankenberg of the SRON-Netherlands Institute for Space Research, et al., in a paper entitled “Dynamic Processes Governing Lower-Tropospheric HDO/H2O Ratios as Observed from Space and Ground,” used a previously overlooked technique to obtain global information with high sensitivity near ground level. This part of the lower troposphere, the bottom 1-2 km of the atmosphere, has previously been missed because earlier satellites used thermal infrared frequencies lacking sensitivity in that area. At the start of the report the authors explain the motivation for their work:

Contrary to what is said in the popular media, water (H2O) is the most important greenhouse gas in Earth's atmosphere, not the small amount of demonized CO2. But aside from acting as a greenhouse gas, water vapor plays an active role in shaping global atmospheric circulation and thus Earth's climate. Water does this by undergoing state changes—from liquid to vapor and back again—allowing water vapor to carry significant amounts of latent heat from the warm equatorial regions toward the poles. The importance of this heat transfer mechanism in climate regulation is poorly understood but new data have begun to show the impact is major. One thing is certain, most widely used climate models do not correctly account for the complex dynamics of water vapor.

In a detailed study of the mechanisms and effects of water vapor, to be published in Reviews of Geophysics, Tapio Schneider and Xavier Levine of the California Institute of Technology, and Paul A. O’Gorman of the Massachusetts Institute of Technology, have expanded our knowledge of water's role in climate regulation while showing just how poorly understood the Earth climate system really is. Our level of collective ignorance is explained at the start of the paper:

This relates to water vapor "feedback" due to CO2's alleged "radiative forcing." See below for further comments from Richard Linzen, Brian Valentine, Lord Monkton, Fred Singer, David Deming & Ben Herman

From A Simple Method to Measure the Dew Point Temperature
by R. L. Snyder, Biometeorology Specialist

Gaseous water molecules consist of one oxygen and two hydrogen atoms. When in a liquid state, the water molecules form strong hydrogen bonds between the molecules. In order to evaporate water, heat must be supplied to break the hydrogen bonds and allow individual molecules to break off as a gas.