Sentences with phrase «increased water vapour levels»

Some point to aerosols (but that is not very plausible, as that should give an increase since 1975 for Europe and in part for North America), but I have the impression that increased water vapour levels are at the base of this change.

Not exact matches

Water vapour levels in the stratosphere increased in the 1990s but dropped by 10 per cent in 2001.

Source: Lyman 2010 The reaction of the oceans to climate change are some of the most profound across the entire environment, including disruption of the ocean food chain through chemical changes caused by CO2, the ability of the sea to absorb CO2 being limited by temperature increases, (and the potential to expel sequestered CO2 back into the atmosphere as the water gets hotter), sea - level rise due to thermal expansion, and the amount of water vapour in the atmosphere.

Scientists agree that a doubling of atmospheric CO2 levels could result in temperature increases of between 1.5 and 4.5 °C, caused by rapid changes such as snow and ice melt, and the behaviour of clouds and water vapour.

As I understand all models they all predict a water vapour based forcing caused by increased temperatures leading to increased levels of water vapour and hence an increased greenhouse effect.

(c) The level of water vapour depends on the global temperature, so it is roughly fixed until something else warms the atmosphere when it increases in amount producing more warming.

However, you have avoided my last comment that without a positive feedback from water vapour there is no chance of runaway global warming arising from increasing atmospheric CO2 levels.

These effects are relatively well understood in the lowest level of the atmosphere, the troposphere, where increased warming leads to greater evaporation, causing more water vapour and so further warming, although this is offset to some extent through the formation of clouds that reflect incoming sunlight back into space.

As the planet warms, increasing levels of water vapour in the atmosphere caused by higher evaporation levels form more clouds and snow increasing the albedo of the planet, reflecting heat back into space more efficiently, thus working to regulate the temperature downward.

Source: Lyman 2010 The reaction of the oceans to climate change are some of the most profound across the entire environment, including disruption of the ocean food chain through chemical changes caused by CO2, the ability of the sea to absorb CO2 being limited by temperature increases, (and the potential to expel sequestered CO2 back into the atmosphere as the water gets hotter), sea - level rise due to thermal expansion, and the amount of water vapour in the atmosphere.

It is my contention (and that of many others) that in fact this is the default null hypothesis and until proponents of the anthropogenic global warming hyothesis come up with some better evidence to back up their claims of imminent dangerous warming driven by co2 and a water vapour feedback to its increasing levels, the null hypothesis is the best one we have.

[44] a reduction of 1/7 of the water vapour content of the air near 300 mbar pushes down by a factor 1 / (1-1/7) 4.7 = 1.03 the P80 % level and the P80 % temperature increases by a factor 1.030.19 = 1.006 that is by about 1.5 K for the radiation temperature over the far infrared spectral range

That increases the CO2 levels near the sea surface (but that is readlily dispersed by convection, as good as the water vapour).

Based on chemical transport model studies, the RF from the increase in stratospheric water vapour due to oxidation of CH4 is estimated to be +0.07 [± 0.05] W m — 2, with a low level of scientific understanding.

It is also very likely that increasing water vapour beyond normal, stable levels leads to various negative feedbacks.

It is well known that a doubling of atmospheric CO2 levels could result in temperature increases of between 1.5 and 4.5 °C, due to fast changes such as snow and ice melt, and the behaviour of clouds and water vapour.

Total water vapour in the atmosphere may increase as the temperature of the surface rises, but if at the same time the mid - to upper - level concentration decreases then water vapour feedback will be negative.

Lindzen doesn't really separate them, he talks about low level cloud feedbacks as being one of the major negative feedbacks that would accrue from increased water vapour and is still consistently saying the same thing.

The models (and there are many) have numerous common behaviours — they all cool following a big volcanic eruption, like that at Mount Pinatubo in 1991; they all warm as levels of greenhouse gases are increased; they show the same relationships connecting water vapour and temperature that we see in observations; and they can quantify how the giant lakes left over from the Ice Age may have caused a rapid cooling across the North Atlantic as they drained and changed ocean circulation patterns.