We found that Colorado River flows decline by about 4 percent per degree F increase, which is roughly the same amount as
the increased atmospheric water vapor holding capacity discussed above.
That increased atmospheric water vapor will also affect cloud cover, though impacts of changes in cloud cover on climate sensitivity are much more uncertain.
Thousands of studies conducted by researchers around the world have documented changes in surface, atmospheric, and oceanic temperatures; melting glaciers; diminishing snow cover; shrinking sea ice; rising sea levels; ocean acidification; and
increasing atmospheric water vapor.
Thousands of studies conducted by researchers around the world have documented changes in surface, atmospheric, and oceanic temperatures; melting glaciers; diminishing snow cover; shrinking sea ice; rising sea levels; ocean acidification; and
increasing atmospheric water vapor.
Not exact matches
The researchers believe the greening is a response to higher
atmospheric carbon dioxide inducing decreases in plant stomatal conductance — the measure of the rate of passage of carbon dioxide entering, or
water vapor exiting, through the stomata of a leaf — and
increases in soil
water, thus enhancing vegetation growth.
By analyzing global
water vapor and temperature satellite data for the lower atmosphere, Texas A&M University
atmospheric scientist Andrew Dessler and his colleagues found that warming driven by carbon dioxide and other gases allowed the air to hold more moisture,
increasing the amount of
water vapor in the atmosphere.
Now if we add
water vapor to the atmosphere it
increases the greenhouse effect in the spectral regions that are not saturated not opaque, which means in the
atmospheric window.
... The Earth's
atmospheric methane concentration has
increased by about 150 % since 1750, and it accounts for 20 % of the total radiative forcing from all of the long - lived and globally mixed greenhouse gases (these gases don't include
water vapor which is by far the largest component of the greenhouse effect).
The factors that determine this asymmetry are various, involving ice albedo feedbacks, cloud feedbacks and other
atmospheric processes, e.g.,
water vapor content
increases approximately exponentially with temperature (Clausius - Clapeyron equation) so that the
water vapor feedback gets stronger the warmer it is.
Global warming also leads to
increases in
atmospheric water vapor, which
increases the likelihood of heavier rainfall events that may cause flooding.
On the other hand, decreasing stratospheric ozone (above 25 km),
increasing stratospheric
water vapor, and
increasing atmospheric CO2 uniformly with height) will produce global surface and tropospheric warming along with stratospheric cooling.
The important point here is that a small external forcing (orbital for ice - ages, or GHG plus aerosols & land use changes in the modern context) can be strongly amplified by the positive feedback mechanism (the strongest and quickest is
atmospheric water vapor - a strong GHG, and has already been observed to
increase.
In Relationships between
Water Vapor Path and Precipitation over the Tropical Oceans, Bretherton et al showed that although the Western Pacific warmer surface waters increased the water in the atmosphere compared to the Eastern Pacific, rainfall was lower in the Western Pacific compared to the Eastern Pacific for equal amounts of water vapor in the atmospheric column — e.g., about 10mm / day in the Western Pacific, versus ~ 20mm / day in the Eastern Pacific at 55 mm water vapor, the peak of the distribution of water vapor amo
Water Vapor Path and Precipitation over the Tropical Oceans, Bretherton et al showed that although the Western Pacific warmer surface waters increased the water in the atmosphere compared to the Eastern Pacific, rainfall was lower in the Western Pacific compared to the Eastern Pacific for equal amounts of water vapor in the atmospheric column — e.g., about 10mm / day in the Western Pacific, versus ~ 20mm / day in the Eastern Pacific at 55 mm water vapor, the peak of the distribution of water vapor amo
Vapor Path and Precipitation over the Tropical Oceans, Bretherton et al showed that although the Western Pacific warmer surface
waters increased the
water in the atmosphere compared to the Eastern Pacific, rainfall was lower in the Western Pacific compared to the Eastern Pacific for equal amounts of water vapor in the atmospheric column — e.g., about 10mm / day in the Western Pacific, versus ~ 20mm / day in the Eastern Pacific at 55 mm water vapor, the peak of the distribution of water vapor amo
water in the atmosphere compared to the Eastern Pacific, rainfall was lower in the Western Pacific compared to the Eastern Pacific for equal amounts of
water vapor in the atmospheric column — e.g., about 10mm / day in the Western Pacific, versus ~ 20mm / day in the Eastern Pacific at 55 mm water vapor, the peak of the distribution of water vapor amo
water vapor in the atmospheric column — e.g., about 10mm / day in the Western Pacific, versus ~ 20mm / day in the Eastern Pacific at 55 mm water vapor, the peak of the distribution of water vapor amo
vapor in the
atmospheric column — e.g., about 10mm / day in the Western Pacific, versus ~ 20mm / day in the Eastern Pacific at 55 mm
water vapor, the peak of the distribution of water vapor amo
water vapor, the peak of the distribution of water vapor amo
vapor, the peak of the distribution of
water vapor amo
water vapor amo
vapor amounts.
Although data are not complete, and sometimes contradictory, the weight of evidence from past studies shows on a global scale that precipitation, runoff,
atmospheric water vapor, soil moisture, evapotranspiration, growing season length, and wintertime mountain glacier mass are all
increasing.
The
atmospheric flux of
water vapor and the associated convergence and divergence
increase in amplitude.
Moreover, the
increase in
atmospheric water vapor content in the Arctic region during late autumn and winter driven locally by the reduction of sea ice provides enhanced moisture sources, supporting
increased heavy snowfall in Europe during early winter, and the northeastern and mid-west United States during winter.
The
water vapor content of the atmosphere rises by about 50 percent if
atmospheric temperatures were to
increase by 5C and relative humidity remained constant.
Add CO2 — >
increased atmospheric LW absorption — > direct radiative constraint from the E (SRF, clear) = 2OLR (clear) geometric requirement — > immediate (instantaneous) negative radiative
water vapor feedback.
Evidence that extreme precipitation is
increasing is based primarily on analysis1, 2,3 of hourly and daily precipitation observations from the U.S. Cooperative Observer Network, and is supported by observed
increases in
atmospheric water vapor.4 Recent publications have projected an
increase in extreme precipitation events, 1,5 with some areas getting larger
increases6 and some getting decreases.7, 2
Therefore, the August - Roche - Magnus equation implies that saturation
water vapor pressure changes approximately exponentially with temperature under typical
atmospheric conditions, and hence the
water - holding capacity of the atmosphere
increases by about 7 % for every 1 °C rise in temperature.
The typical logic is this: adding CO2 — >
increased atmospheric LW absorption — > temperature adjustment — > negative
water vapor / cloud feedback.
Of course, when it comes to the
atmospheric temperature
increase caused by a doubling of CO2, the
water vapor feedback is critical in determining the final outcome.
One of the most substantial climate changes in response to global warming is the
increase in
atmospheric water vapor content.
Since
water vapor contributes 95 % of the wrongly named «greenhouse effect» and since the
increase in
atmospheric carbon dioxide has a logarithmic and declining effect, the variation in temperature at the surface must be vanishingly small.
But, just in case you were semi-serious: With oceans covering 70 % of the earth's surface, you could never change
atmospheric humidity —
water vapor pressure is a function of
atmospheric temperature,
increasing as temperature rises.
Some of the mid-latitude
increase of stratospheric
water vapor (1 % per year) over the period of 1980 - 2006 can be explained by the
increase of
atmospheric methane, but not all.
1 Positive 1.1 Carbon cycle feedbacks 1.1.1 Arctic methane release 1.1.1.1 Methane release from melting permafrost peat bogs 1.1.1.2 Methane release from hydrates 1.1.2 Abrupt
increases in
atmospheric methane 1.1.3 Decomposition 1.1.4 Peat decomposition 1.1.5 Rainforest drying 1.1.6 Forest fires 1.1.7 Desertification 1.1.8 CO2 in the oceans 1.1.9 Modelling results 1.1.9.1 Implications for climate policy 1.2 Cloud feedback 1.3 Gas release 1.4 Ice - albedo feedback 1.5
Water vapor feedback 2 Negative 2.1 Carbon cycle 2.1.1 Le Chatelier's principle 2.1.2 Chemical weathering 2.1.3 Net Primary Productivity 2.2 Lapse rate 2.3 Blackbody radiation
Water vapor then reacts to this
increased absorption, its concentration in air diminishes, its share of IR absorption goes down, and
atmospheric transmittance is restored to its nominal 15 percent again.
3 Further complicating the response of the different
atmospheric levels to
increases in greenhouse gases are other processes such as those associated with changes in the concentration and distribution of
atmospheric water vapor and clouds.
His model runs had
atmospheric water vapor dropping by 90 % after CO2 was removed, but cloud cover
increasing by 50 %, resulting in a world that would be a perpetually cloud - covered desert.
It's my understanding that NVAP data shows as
atmospheric CO2
increases,
water vapor decreases; exactly opposite what climate models predict because they assume
water vapor is a net positive feedback; more wv, more warming, more wv, more warming.....
The Equilibrium Climate Sensitivity (ECS) The Economist refers to is how much Earth temperatures are expected to rise when one includes fast feedbacks such as
atmospheric water vapor increase and the initial greenhouse gas forcing provided by CO2.
The IPCC, its models, and the climate establishment insist warming will be more than this because the warming will cause an
increase in
atmospheric water vapor (the major greenhouse gas) which will amplify the CO2 - caused warming, a net positive feedback.
For more than 10 years (I forgot how much more), upper tropospheric
water vapor has not
increased in response to significant
increases in CO2
atmospheric concentrations.
Some climate scientists are claiming that more extreme weather events are occurring than in the past, and that the primary reason is because the atmosphere contains more
water vapor due to the
increase in the average global
atmospheric temperature.
These observations show large - scale
increases in air and sea temperatures, sea level, and
atmospheric water vapor....»
Negative trends in q as found in the NCEP data would imply that long - term
water vapor feedback is negative — that it would reduce rather than amplify the response of the climate system to external forcing such as that from
increasing atmospheric CO2.
The basic results of this climate model analysis are that: (1) it is
increase in
atmospheric CO2 (and the other minor non-condensing greenhouse gases) that control the greenhouse warming of the climate system; (2)
water vapor and clouds are feedback effects that magnify the strength of the greenhouse effect due to the non-condensing greenhouse gases by about a factor of three; (3) the large heat capacity of the ocean and the rate of heat transport into the ocean sets the time scale for the climate system to approach energy balance equilibrium.
Moreover, the
increase in
atmospheric water vapor content in the Arctic region during late autumn and winter driven locally by the reduction of sea ice provides enhanced moisture sources, supporting
increased heavy snowfall in Europe during early winter and the northeastern and midwestern United States during winter.
Note that this is only part of the story since, as far as we are aware, no one has yet investigated a counterintuitive parallel effect — condensation and precipitation will likely reduce the total lower
atmospheric concentration of that ubiquitous greenhouse gas,
water vapor, so
increasing clear sky radiative cooling.
atmospheric absorption by CO2 and
water vapor increases, reducing the solar heating at the surface, and surface evaporation
increases faster with temperature than the transfer of sensible heat (due to the Clausius - Clapeyron relation), both of which tend to reduce the diurnal cycle.
One of the most well - known effects of global warming is an intensification of the
water cycle, with higher air temperatures leading to
increased evaporation from the seas and soils, and more
atmospheric water vapor contributing to more frequent heavy precipitation events.
Once permafrost starts melting, there are feedbacks from changes in albedo, methane emissions, the thermal properties of surface
water, and
increases in
atmospheric water vapor.
While it was true that the
atmospheric concentration of carbon dioxide had been
increasing, he said, and had passed 400 parts per million, the dominant effect of
water vapor had helped flatten the greenhouse effect, such that the rise of global surface temperatures had slowed significantly.
Regardless, climate models are made interesting by the inclusion of «positive feedbacks» (multiplier effects) so that a small temperature increment expected from
increasing atmospheric carbon dioxide invokes large
increases in
water vapor, which seem to produce exponential rather than logarithmic temperature response in the models.