Klimatbloggen

2013-01-01

Vattenånga

Mängden vatten i luften styrs av dess värme. Mängden vatten kan variera från några kilo till 70 kilo i tropikerna.

Mängden vattenånga i atmosfären styrs av temperaturen. En typisk kolonn av luft från marken till stratosfären kan innehålla några kilo vatten per kvadratmeter, medans en sådan kolumn med luft i tropikerna kan innehålla 70 kg vatten. 

Varje ytterligare grad av värme i atmosfärens ökar mängden vatten med ca 7%. Ökad värme i atmosfären innebär förstärkt växthuseffekt som lder till ökad värme.

The maximum amount of water vapour in the air is controlled by temperature. A typical column of air extending from the surface to the stratosphere in polar regions may contain only a few kilograms of water vapour per square metre, while a similar column of air in the tropics may contain up to 70 kg. With every extra degree of air temperature, the atmosphere can retain around 7% more water vapour (see upper-left insert in the FAQ 8.1, Figure 1). This increase in concentration amplifes the greenhouse effect, and therefore leads to more warming.

This process, referred to as the water vapour feedback, is well understood and quantifed. It occurs in all models used to estimate climate change, where its strength is consistent with observations. Although an increase in atmospheric water vapour has been observed, this change is recognized as a climate feedback (from increased atmospheric temperature) and should not be interpreted as a radiative forcing from anthropogenic emissions. 

Currently, water vapour has the largest greenhouse effect in the Earth’s atmosphere. However, other greenhouse gases, primarily CO2, are necessary to sustain the presence of water vapour in the atmosphere. Indeed, if these other gases were removed from the atmosphere, its temperature would drop suffciently to induce a decrease of water vapour, leading to a runaway drop of the greenhouse effect that would plunge the Earth into a frozen state. So greenhouse gases other than water vapour provide the temperature structure that sustains current levels of atmospheric water vapour. Therefore, although CO2 is the main anthropogenic control knob on climate, water vapour is a strong and fast feedback that amplifes any initial forcing by a typical factor between two and three. Water vapour is not a signifcant initial forcing, but is nevertheless a fundamental agent of climate change

IPCC Sida 666-667

Till Alla

2013-01-01

Vattenånga

Mängden vatten i luften styrs av dess värme. Mängden vatten kan variera från några kilo till 70 kilo i tropikerna.

Mängden vattenånga i atmosfären styrs av temperaturen. En typisk kolonn av luft från marken till stratosfären kan innehålla några kilo vatten per kvadratmeter, medans en sådan kolumn med luft i tropikerna kan innehålla 70 kg vatten. 

Varje ytterligare grad av värme i atmosfärens ökar mängden vatten med ca 7%. Ökad värme i atmosfären innebär förstärkt växthuseffekt som lder till ökad värme.

The maximum amount of water vapour in the air is controlled by temperature. A typical column of air extending from the surface to the stratosphere in polar regions may contain only a few kilograms of water vapour per square metre, while a similar column of air in the tropics may contain up to 70 kg. With every extra degree of air temperature, the atmosphere can retain around 7% more water vapour (see upper-left insert in the FAQ 8.1, Figure 1). This increase in concentration amplifes the greenhouse effect, and therefore leads to more warming.

This process, referred to as the water vapour feedback, is well understood and quantifed. It occurs in all models used to estimate climate change, where its strength is consistent with observations. Although an increase in atmospheric water vapour has been observed, this change is recognized as a climate feedback (from increased atmospheric temperature) and should not be interpreted as a radiative forcing from anthropogenic emissions. 

Currently, water vapour has the largest greenhouse effect in the Earth’s atmosphere. However, other greenhouse gases, primarily CO2, are necessary to sustain the presence of water vapour in the atmosphere. Indeed, if these other gases were removed from the atmosphere, its temperature would drop suffciently to induce a decrease of water vapour, leading to a runaway drop of the greenhouse effect that would plunge the Earth into a frozen state. So greenhouse gases other than water vapour provide the temperature structure that sustains current levels of atmospheric water vapour. Therefore, although CO2 is the main anthropogenic control knob on climate, water vapour is a strong and fast feedback that amplifes any initial forcing by a typical factor between two and three. Water vapour is not a signifcant initial forcing, but is nevertheless a fundamental agent of climate change

IPCC Sida 666-667

Till Alla
Taggar: Vattenånga IPCC Temperatur Koldioxid

2013-01-01

Vattenånga

Mängden vatten i luften styrs av dess värme. Mängden vatten kan variera från några kilo till 70 kilo i tropikerna.

Mängden vattenånga i atmosfären styrs av temperaturen. En typisk kolonn av luft från marken till stratosfären kan innehålla några kilo vatten per kvadratmeter, medans en sådan kolumn med luft i tropikerna kan innehålla 70 kg vatten. 

Varje ytterligare grad av värme i atmosfärens ökar mängden vatten med ca 7%. Ökad värme i atmosfären innebär förstärkt växthuseffekt som lder till ökad värme.

The maximum amount of water vapour in the air is controlled by temperature. A typical column of air extending from the surface to the stratosphere in polar regions may contain only a few kilograms of water vapour per square metre, while a similar column of air in the tropics may contain up to 70 kg. With every extra degree of air temperature, the atmosphere can retain around 7% more water vapour (see upper-left insert in the FAQ 8.1, Figure 1). This increase in concentration amplifes the greenhouse effect, and therefore leads to more warming.

This process, referred to as the water vapour feedback, is well understood and quantifed. It occurs in all models used to estimate climate change, where its strength is consistent with observations. Although an increase in atmospheric water vapour has been observed, this change is recognized as a climate feedback (from increased atmospheric temperature) and should not be interpreted as a radiative forcing from anthropogenic emissions. 

Currently, water vapour has the largest greenhouse effect in the Earth’s atmosphere. However, other greenhouse gases, primarily CO2, are necessary to sustain the presence of water vapour in the atmosphere. Indeed, if these other gases were removed from the atmosphere, its temperature would drop suffciently to induce a decrease of water vapour, leading to a runaway drop of the greenhouse effect that would plunge the Earth into a frozen state. So greenhouse gases other than water vapour provide the temperature structure that sustains current levels of atmospheric water vapour. Therefore, although CO2 is the main anthropogenic control knob on climate, water vapour is a strong and fast feedback that amplifes any initial forcing by a typical factor between two and three. Water vapour is not a signifcant initial forcing, but is nevertheless a fundamental agent of climate change

IPCC Sida 666-667

Till Alla
Taggar: Vattenånga IPCC Temperatur Koldioxid

Red: Hans Iwan Bratt. epost: hibratt@gmail.com.