Though not exactly the same as PWAT, the absolute humidity at the surface is likely very closely related in terms of percentage change. The absolute humidity level above the saturation level at 55 F is the critical factor in determining how much electricity will be needed for air-conditioning systems, which are generally designed to remove any excess humidity. A bit of thermodynamic analysis will show that it costs about 20X as much energy (electricity) to cool (i.e., air condition) moist air as to cool dry air. So the chart of PWAT levels and its history of increase over time is also an indication of the increase in air-conditioning load that is occurring--and the factor of 20 or so multiplier for dealing with it is one reason why people are facing higher and higher electricity costs. Essential advice for keeping air conditioning costs down is keeping as much of the increasing atmospheric moisture outdoors, and so minimizing opening of doors and windows is a key way to keep these costs down.
you should also note that water vapor itself is also driving the rise in global temperatures. Water vapor is a potent greenhouse gas and carries with it a positive feedback on the warming effect (warmer global temps increase absolute average humidity in the atmosphere which drives up average global temps, etc.).
Water vapor is also a greenhouse gas, and higher greenhouse effect means higher temperature which means higher water vapor level...and so on and so on. A self-reinforcing cycle.
PWAT is also often referred to as Total column water vapor. TCWV. More descriptive.
However, it has a high dependence on temperature, as you suggest. But that relation is extremely nonlinear, and so most of what is described as "global" is really tropical, or 30N to 30S. Then it is the atmospheric rivers that affect the mid-latitudes. And the main effect is on intensity of rainfail, not amount. So the rains (and snows) are heavier but shorter in duration typically. The total amount depends on evaporation which in turn depends on the surface energy budget, that changes much less, especially because of aerosols.
You may find this useful from The Conversation in 2023:
How rising water vapour in the atmosphere is amplifying warming and making extreme weather worse, 14 September 2023. https://doi.org/10.64628/AA.3yf9fkrpg
This information has value for a certain number of people. But, according to Yale Climate Connections research, not very many people will connect heavy flood events with climate change. The majority of American's response is, "You want me to stop eating hamburgers because it's hot in the summer? Get real." I feel like a rational people would start preparing for worse flooding.
I have analyzed precipitation data where I live in Grey County, Ontario, Canada and have shown how heavy 5-day events have increased exponentially over the previous three decades. Specific to our location is less ice cover on Lake Huron leading to greater evaporation during winter, along with increasing temperatures.
To riff on your recent statement, Professor Dessler, the climate train that is going to run us over if we just stand there is carrying a lot of water...
I send a copy of some of your articles to one or more groups. To this one I added: "after we stop “dumping carbon into the atmosphere” the level of climate impacts that exist are likely to continue for at least hundreds of years. Thus, to hold that level of climate impacts as low as possible, it is necessary to reduce emissions ASAP."
100,000 years! I had no idea it would take that long! Will you please post on this? Explain WHY. (It is too easy to see individual trees but miss the forest, so to speak. Please help us see the forest -- not just individual trees.) Is civilization doomed in the next few hundreds of years, no matter what we do?
What if we, I don't know, all went plant based (or the human population decreased from effects of climate change including from starving) and about 5/6th of land currently used for animal ag (pasture and crops) could be reforested to start sucking some of the dumped co2 out of the atmosphere? Would that bring temperatures back down more quickly than 100, 000 years?
You could add that we will see a temp increase due to the short Sulphur residency times in the 60% of the fossil fuel burning that is currently un scrubbed. Tom from climate uncovered says he will be doing an article on this in the coming weeks.
A post on the 100,000 years question. Reasoning why global temperatures do not decrease for long AFTER our emissions have stopped, include:
A. Existing atmospheric CO2 will take centuries to dissipate; science indicates that 10% of that CO2 will remain in 100,000 years (assumes effective technology for CDR is not invented). Looking at the last 400,000 years of global temperature and CO2 will show that 100,000-year cycle. Scientists provide a more detailed explanation.
B. From deep in the Skeptical Science item at https://skepticalscience.com/stop-emissions-stop-warming.html; “The cooling effect of declining CO2 levels tends to offset the warming caused by heat transfer into the deep ocean. This balance means that, after emissions stop, global temperatures are expected to remain relatively stable instead of significantly rising or falling.”
The following sentence from my original comment: “Thus, to hold that level of climate impacts as low as possible, it is necessary to reduce emissions ASAP."
We must not pass over the issue of warmer air requiring more water vapor to reach saturation - for it to rain at all. Whilst the conditions conducive to rainfall lead to heavier falls where those conditions are less common it can lead to more evaporation, lighter falls and more intense droughts.
This should correct for the height of the Troposphere to reflect volume better. We pretty much know that war and humid air is moving towards arctic regions during summer time to excessive degrees as it's failing to rain over equator, something that these extreme events doesn't really correct for.
I agree. Half of water vapour is below 1.5 Km (5,000 feet). 90% of it is below 4.5 Km (15,000 feet). 99.13% is in the troposphere (on average up to 10 Km, or the lowest ¾ of the atmosphere by mass). This is because the cold, less dense, air aloft can hold little water vapour.
How much is that compared to whats below sea surface? Sorry for the sarcasm, but water vapor is the only thing that matters for stratospheric jet streams, not temperature. While below the troposphere, it's "look, alot of water, that means it's warm and doesn't rain enough".
Good to know, but the practical implications doesn't seem to be that way. It goes into the stratosphere where it destabilizes the jet streams. I've become a bit interested in the topic as it seems to be big deal around observed discreoencies, the consequences to the polar cells is apoarantly a major topic.
Wondering if the cost of diesel fuel and oil in general around the world will impact a transition away from those fuels due to issues in the Middle East and perhaps have some impact on slowing the increase of CO2 and other gases in the atmosphere. I realize damage done, but right now I’m looking at alternatives to heating my home for the winter season.
Most impact assessments I read still size drainage and cooling from a 30-year climate normal. If atmospheric moisture is already outside that record, the normal is a lagging baseline. Is there a defensible way to carry the vapour trend into design rainfall intensity, beyond applying the ~7% per degree scaling as a flat uplift?
Though not exactly the same as PWAT, the absolute humidity at the surface is likely very closely related in terms of percentage change. The absolute humidity level above the saturation level at 55 F is the critical factor in determining how much electricity will be needed for air-conditioning systems, which are generally designed to remove any excess humidity. A bit of thermodynamic analysis will show that it costs about 20X as much energy (electricity) to cool (i.e., air condition) moist air as to cool dry air. So the chart of PWAT levels and its history of increase over time is also an indication of the increase in air-conditioning load that is occurring--and the factor of 20 or so multiplier for dealing with it is one reason why people are facing higher and higher electricity costs. Essential advice for keeping air conditioning costs down is keeping as much of the increasing atmospheric moisture outdoors, and so minimizing opening of doors and windows is a key way to keep these costs down.
All the more reason for passive cooling. We have to fry, or rather, let the "others" fry first before we act.
We can can stave off alot of harm brightening the urban mark.
And, water.. we gotta bring back the water that we depleted on the lands. No water.. no cdt.
you should also note that water vapor itself is also driving the rise in global temperatures. Water vapor is a potent greenhouse gas and carries with it a positive feedback on the warming effect (warmer global temps increase absolute average humidity in the atmosphere which drives up average global temps, etc.).
Grab the oars!
And the sand bags.
Water vapor is also a greenhouse gas, and higher greenhouse effect means higher temperature which means higher water vapor level...and so on and so on. A self-reinforcing cycle.
PWAT is also often referred to as Total column water vapor. TCWV. More descriptive.
However, it has a high dependence on temperature, as you suggest. But that relation is extremely nonlinear, and so most of what is described as "global" is really tropical, or 30N to 30S. Then it is the atmospheric rivers that affect the mid-latitudes. And the main effect is on intensity of rainfail, not amount. So the rains (and snows) are heavier but shorter in duration typically. The total amount depends on evaporation which in turn depends on the surface energy budget, that changes much less, especially because of aerosols.
You may find this useful from The Conversation in 2023:
How rising water vapour in the atmosphere is amplifying warming and making extreme weather worse, 14 September 2023. https://doi.org/10.64628/AA.3yf9fkrpg
Kevin
Thanks for the comment, Kevin
Good info. Thanks.
This information has value for a certain number of people. But, according to Yale Climate Connections research, not very many people will connect heavy flood events with climate change. The majority of American's response is, "You want me to stop eating hamburgers because it's hot in the summer? Get real." I feel like a rational people would start preparing for worse flooding.
I have analyzed precipitation data where I live in Grey County, Ontario, Canada and have shown how heavy 5-day events have increased exponentially over the previous three decades. Specific to our location is less ice cover on Lake Huron leading to greater evaporation during winter, along with increasing temperatures.
I love that you add post-specific code to github. Awesome!
Water we going to do?
To riff on your recent statement, Professor Dessler, the climate train that is going to run us over if we just stand there is carrying a lot of water...
I send a copy of some of your articles to one or more groups. To this one I added: "after we stop “dumping carbon into the atmosphere” the level of climate impacts that exist are likely to continue for at least hundreds of years. Thus, to hold that level of climate impacts as low as possible, it is necessary to reduce emissions ASAP."
the impacts will continue for much longer than hundreds of years. the climate will not return to pre-industrial temperatures for 100,000 years.
100,000 years! I had no idea it would take that long! Will you please post on this? Explain WHY. (It is too easy to see individual trees but miss the forest, so to speak. Please help us see the forest -- not just individual trees.) Is civilization doomed in the next few hundreds of years, no matter what we do?
What if we, I don't know, all went plant based (or the human population decreased from effects of climate change including from starving) and about 5/6th of land currently used for animal ag (pasture and crops) could be reforested to start sucking some of the dumped co2 out of the atmosphere? Would that bring temperatures back down more quickly than 100, 000 years?
You could add that we will see a temp increase due to the short Sulphur residency times in the 60% of the fossil fuel burning that is currently un scrubbed. Tom from climate uncovered says he will be doing an article on this in the coming weeks.
A post on the 100,000 years question. Reasoning why global temperatures do not decrease for long AFTER our emissions have stopped, include:
A. Existing atmospheric CO2 will take centuries to dissipate; science indicates that 10% of that CO2 will remain in 100,000 years (assumes effective technology for CDR is not invented). Looking at the last 400,000 years of global temperature and CO2 will show that 100,000-year cycle. Scientists provide a more detailed explanation.
B. From deep in the Skeptical Science item at https://skepticalscience.com/stop-emissions-stop-warming.html; “The cooling effect of declining CO2 levels tends to offset the warming caused by heat transfer into the deep ocean. This balance means that, after emissions stop, global temperatures are expected to remain relatively stable instead of significantly rising or falling.”
The following sentence from my original comment: “Thus, to hold that level of climate impacts as low as possible, it is necessary to reduce emissions ASAP."
We talked about the relevant physical processes here: https://www.theclimatebrink.com/p/climate-change-will-stop-when-we
Indeed, the SkepticalScience item is a repost of yours!
We must not pass over the issue of warmer air requiring more water vapor to reach saturation - for it to rain at all. Whilst the conditions conducive to rainfall lead to heavier falls where those conditions are less common it can lead to more evaporation, lighter falls and more intense droughts.
This should correct for the height of the Troposphere to reflect volume better. We pretty much know that war and humid air is moving towards arctic regions during summer time to excessive degrees as it's failing to rain over equator, something that these extreme events doesn't really correct for.
Height of the troposphere makes no difference. Almost all of the column water vapors in the bottom 5 km.
I agree. Half of water vapour is below 1.5 Km (5,000 feet). 90% of it is below 4.5 Km (15,000 feet). 99.13% is in the troposphere (on average up to 10 Km, or the lowest ¾ of the atmosphere by mass). This is because the cold, less dense, air aloft can hold little water vapour.
How much is that compared to whats below sea surface? Sorry for the sarcasm, but water vapor is the only thing that matters for stratospheric jet streams, not temperature. While below the troposphere, it's "look, alot of water, that means it's warm and doesn't rain enough".
Good to know, but the practical implications doesn't seem to be that way. It goes into the stratosphere where it destabilizes the jet streams. I've become a bit interested in the topic as it seems to be big deal around observed discreoencies, the consequences to the polar cells is apoarantly a major topic.
https://www.nature.com/articles/s41467-023-39559-2/figures/1
Wondering if the cost of diesel fuel and oil in general around the world will impact a transition away from those fuels due to issues in the Middle East and perhaps have some impact on slowing the increase of CO2 and other gases in the atmosphere. I realize damage done, but right now I’m looking at alternatives to heating my home for the winter season.
Most impact assessments I read still size drainage and cooling from a 30-year climate normal. If atmospheric moisture is already outside that record, the normal is a lagging baseline. Is there a defensible way to carry the vapour trend into design rainfall intensity, beyond applying the ~7% per degree scaling as a flat uplift?
If the PWAT increased by 0.04 mm then the sea level should have decreased by about 0.05+ mm or so. Did the sea level data show this?