What is the correct value of Climate Sensitivity?

[TimG]

They store water on top when there is precipitation and cold enough temps to freeze it.

They store water as snow that builds up during the rainy season. That snow melts slowly and releases water over the course of a season. A dam does exactly the same by storing water in a reservoir rather than snow. Seasonal freeze/melt processes make no contribution to sea level rise. Edited April 1, 2015 by TimG

[On Guard for Thee]

They store water as snow that builds up during the rainy season. That snow melts slowly and releases water over the course of a season. A dam does exactly the same by storing water in a reservoir rather than snow. Seasonal freeze/melt processes make no contribution to sea level rise.

Once again, a dam stores water, ONLY when there is water flow to be damed. When warming temps decrease the conditions that replenish the glacier ad increase the time it is melting, you eventually have no more glacier, so your dam becomes a white elephant. Now where do you reckon that water that was stored in the glacier ends up...well around where I live it ends up in the pacific ocean. Which is kinda getting peoples feet wet in the Marshal Islands for instance.

[TimG]

When warming temps decrease the conditions that replenish the glacier ad increase the time it is melting, you eventually have no more glacier, so your dam becomes a white elephant.

You clearly do not understand the processes you claim to be "alarmed" about. Global warming will increase precipitation so there will be more water available to store. The problem is this precipitation is not available when people need it - hence the need for a dam. The only thing the glacier does is slow down the release of water each season. The glacier can disappear and the rain will still fall. The glacier does not provide access to additional water.

[On Guard for Thee]

You clearly do not understand the processes you claim to be "alarmed" about. Global warming will increase precipitation so there will be more water available to store. The problem is this precipitation is not available when people need it - hence the need for a dam. The only thing the glacier does is slow down the release of water each season. The glacier can disappear and the rain will still fall. The glacier does not provide access to additional water.

There is no such thing as additional water, the problem with a declining glacier is the water is no longer where people have come to depend on it. Yes rain will still fall, somewhere, but maybe not in such a way as to flow to our dam. So we could end up high and pretty dry, while people on low elevation islands get flooded.

[TimG]

Yes rain will still fall, somewhere, but maybe not in such a way as to flow to our dam.

If you put the dam where the glacier was then all the water that was released by the glacier will be now stored in the reservoir and released as needed.

[On Guard for Thee]

If you put the dam where the glacier was then all the water that was released by the glacier will be now stored in the reservoir and released as needed.

Why would you put a dam where a glacier WAS...No glacier, no water, no dam needed.

And you say I dont understand...doodle

[TimG]

Why would you put a dam where a glacier WAS...No glacier, no water, no dam needed.

Glaciers matter for water supply because they store rainfall that falls in the mountains during the rainy season.

If the glacier is not there the rain falls and immediately flows to the ocean which means it will not be available during the dry season.

When the glacier goes you can put a dam in that stores the water from the rainy season and releases it as needed.

Glaciers can disappear and we don't really care. We don't need them. We have alternatives.

OTOH, we can't get rid of CO2 emissions because we have no viable alternatives to fossil fuels.

Edited April 1, 2015 by TimG

[-1=e^ipi]

On Guard for Thee, do you understand the concept of conservation of mass? If a community is getting water from a glacier, where is the glacier getting its water from?

[On Guard for Thee]

Glaciers matter for water supply because they store rainfall that falls in the mountains during the rainy season.

If the glacier is not there the rain falls and immediately flows to the ocean which means it will not be available during the dry season.

When the glacier goes you can put a dam in that stores the water from the rainy season and releases it as needed.

Glaciers can disappear and we don't really care. We don't need them. We have alternatives.

OTOH, we can't get rid of CO2 emissions because we have no viable alternatives to fossil fuels.

Glaciers are typically at high elevations, such as in mountain ranges. Take away the storage unit (glacier) the rain that falls in its place will take various ways of making its way down the slope. How many dams were you planning on building I wonder. And saying we dont need glaciers once again ignores the sea level rise that will create. I think its clear who the idiot is, if you want to get into that sort of childishness.

[On Guard for Thee]

On Guard for Thee, do you understand the concept of conservation of mass? If a community is getting water from a glacier, where is the glacier getting its water from?

We have already got that figured out a few posts ago.

[TimG]

Glaciers are typically at high elevations, such as in mountain ranges.

Glaciers are rivers of ice. When they disappear a river valley is left. All the precipitation that used to fall on the glacier will now flow through the river valley. One dam for each glacier is all that is needed. Edited April 1, 2015 by TimG

[On Guard for Thee]

Glaciers are rivers of ice. When they disappear a river valley is left. All the precipitation that used to fall on the glacier will now flow through the river valley. One dam for each glacier is all that is needed.

Oh were it only that simple. Glaciers exist at higher levels with varied elevations. The precip that falls on a glacier becomes ice and replenishes it from the top. As the weather warms it reaches the lower levels of the ice and melts it from there and that water is directed down the valley. Trouble is if you replace that big storage device and just rely on the rain or snow, your river may well be just a trickle as that rain or snow melt heads off in multiple directions. As well, the glacier acts as a buffer during drought years when they happen.

[WIP]

CO2 emissions have not fallen.

I wasn't talking about atmospheric emissions...which are certainly rising, and at an exponentially increasing rate according to the Scripps Institute: latest reading on March 29, is 403.18 ppm....that's from Mauna Loa Observatory in Hawaii btw. What I was talking about was this good news story reported at Vox....which is a clickbait news site no doubt, but they were reporting on some preliminary findings that global human produced emissions for 2014 will show a decoupling....since a flat or a slight decline in emissions at a time when global economies are supposedly increasing at 3%. If true, this would be the first time that a decline in human produced CO2 emissions occurred without an economic decline in the global economies. It would mean that a growing shift to non-carbon emitting energy sources is bearing fruit. But, cynic that I am, I have another statistical term for everyone to consider: Jevon's Paradox - because past examples, like improved exhausts to reduce air pollution, show that, in a consumer demand-driven economy, ecological improvements are short term relief that cannot stop the long term trend towards more pollution and ecological destruction. In the air pollution case, more cars on the roads soon erased those improvements created by adding new catalytic converters to the exhausts, and improving fuel efficiency.

Worth noting that CO2 is only one greenhouse gas. The other main culprit - methane CH4, is being released at an increasingly rapid rate in the Arctic, as permafrost melts and frozen methane, trapped in colder ocean layers as clathrates, are being released. There is still nothing resembling a complete assessment for how much stored methane is locked in to oceans and soils, or how much can be released at different temperature levels. What we have now, is the greatest physics experiment being done in human history; and the entire world is the laboratory for this experiment on the unknown! Just sayin, when the IPCC referees give a number of having 2 degrees C more room for global average temp increases, we are just taking the word of bureaucrats who've taken the percentages of risks and set up the public presentation as having some sort of carbon reserves that we can still safely burn before we enter that escalating rate of uncontrolled climate change. The promised reserve is coming from the same people who promised that Arctic Ocean would still have ice till the end of this century!

Ocean acidification occurs due to CO2 being taken out of the atmosphere and being dissolved in the oceans. So there is a tradeoff here. The more ocean acidification, the less global warming. Ocean uptake of atmospheric CO2 has a decay time of on the order of centuries. Current ocean pH is about 8.14. By 2100, it might be like 7.82 at worst. A significant change but not the end of the world. Ocean pH has been far lower in the past when atmospheric CO2 levels were many times greater than they are now and ocean pH was even lower, yet life thrived.

And we aren't living in those times! It has to be taken into account that the changes being made today are going to take centuries or thousands of years to feel the full impacts. In the meantime, we continue adding more carbon to the atmosphere. If the oceans reach a saturation level and can't absorb more carbon, what happens then? Remember, up till now, it's been estimated that half of the carbon added to the atmosphere is absorbed by the oceans. So, the oceans have already been the primary sink up till now. If that ends, we're in a spiral of rapid climate change....which has also happened in the past.

Why wouldn't it matter? If climate sensitivity is say 30% lower than what the IPCC is claiming, then that means there will be 30% less warming, which means that the appropriate policy response can be quite different. And the IPCC claims and any mainstream climate science position of climate sensitivity is still orders of magnitude lower than what idiot alarmists like Obama think it is.

htt

"The planet will boil over"

There are no signs nor indications of any serious plan being proposed to deal with increasing carbon emissions, or the other ecological crises caused by overpopulation+ever-increasing economic demands. Endless growth is not compatible with life on a finite planet. At some point it starts breaking down, and that time may be starting sooner than we think.

[TimG]

Oh were it only that simple. Glaciers exist at higher levels with varied elevations.

It is that simple. If the snow did not flow into the glacier valley it would not be available for ice melt. Ice or water - it follows the same paths.

[Keepitsimple]

There are no signs nor indications of any serious plan being proposed to deal with increasing carbon emissions, or the other ecological crises caused by overpopulation+ever-increasing economic demands. Endless growth is not compatible with life on a finite planet. At some point it starts breaking down, and that time may be starting sooner than we think.

Yes - the key to population management is good governance, a working economy - and formal education. Unless we continue to help third world countries along the path to achieving all three, we'll continue to fight a losing battle. I'd like to think that as Communism's group-think collapsed under the weight of human oppression, the Middle East may be experiencing its awakening. ISIS and its kin have accelerated the recognition of the warts of Islamic "governance" and the need to separate church/mosque/temple and State. Evolution/revolution is sloppy and dirty but when people genuinely look for Reasonable Accommodation, there's hope for everyone in the longer term - because it doesn't happen overnight. That's why Quebec's search for that elusive accommodation is such an important discussion - and why Canadians are so seized with the Niqab/Oath of Citizenship argument. It's a healthy discussion to have - because as our Charter says - rights are not absolute.....tolerance and accommodation must bereciprocal as the East/West evolution seeks to find its way.

[-1=e^ipi]

which are certainly rising, and at an exponentially increasing rate according to the Scripps Institute

That exponential rate of increase is breaking down. Over the next half century, CO2 emissions will increase roughly quadratically, not exponentially.

Worth noting that CO2 is only one greenhouse gas. The other main culprit - methane CH4, is being released at an increasingly rapid rate in the Arctic, as permafrost melts and frozen methane, trapped in colder ocean layers as clathrates, are being released. There is still nothing resembling a complete assessment for how much stored methane is locked in to oceans and soils, or how much can be released at different temperature levels.

The release of CO2, CH4 and N2O from oceans, permafrost and glaciers due to a given temperature increase can be inferred from Pleistocene ice core data.

Just sayin, when the IPCC referees give a number of having 2 degrees C more room for global average temp increases, we are just taking the word of bureaucrats who've taken the percentages of risks and set up the public presentation

The 2C target is an entirely political target with no scientific basis.

The promised reserve is coming from the same people who promised that Arctic Ocean would still have ice till the end of this century!

Of course there will be ice at the end of this century. It is called winter. Or do you mean a polar ice cap?

And we aren't living in those times! It has to be taken into account that the changes being made today are going to take centuries or thousands of years to feel the full impacts.

No, it would take infinite time to reach the 'full impact'. Trying to describe climate change in terms of how long it takes to reach 'full impact' is nonsensical. A better question would be how long will it take to reach a certain percentage of the 'full impact'.

In the meantime, we continue adding more carbon to the atmosphere. If the oceans reach a saturation level and can't absorb more carbon, what happens then?

This isn't how physics works. In equilibrium, dissolved oceanic CO2 follows Henry's Law and is proportional to atmospheric CO2. The oceans aren't going to some day decide to stop absorbing CO2, the rate of CO2 uptake will be roughly proportional to the difference between atmospheric CO2 and Henry's constant times the Oceanic concentration of dissolved CO2.

Remember, up till now, it's been estimated that half of the carbon added to the atmosphere is absorbed by the oceans. So, the oceans have already been the primary sink up till now.

The rate of ocean uptake of atmospheric CO2 divided by anthropogenic CO2 emissions is slightly less than half. However, in equilibrium, the oceans will absorb roughly 85% of Human emissions (this follows from the properties of Ocean water + Henry's law, see earlier posts). Of course the decay time towards equilibrium between Ocean dissolved CO2 concentrations and atmospheric CO2 concentrations is greater than a century. The oceans will continue to take up ~half of anthropogenic CO2 emissions annually for the next century; it follows from physics (+ emission scenarios).

There are no signs nor indications of any serious plan being proposed to deal with increasing carbon emissions

Here's a plan: implement a global tax on CO2 emissions where the level of taxation is equal to the marginal social cost of CO2 emissions (which is determined from a cost-benefit analysis).

[On Guard for Thee]

On Guard for Thee, do you understand the concept of conservation of mass? If a community is getting water from a glacier, where is the glacier getting its water from?

I bet even you understand enough about meteorology to figure that one out. You seem to have a problem with what happens after the glacier is gone though. Give you a hint though, it gets pretty dry in the neighbourhood.

[-1=e^ipi]

I bet even you understand enough about meteorology to figure that one out. You seem to have a problem with what happens after the glacier is gone though. Give you a hint though, it gets pretty dry in the neighbourhood.

Guess I have to spell it out for you.

In the long run, the amount of precipitation on Earth equals the amount of evaporation on Earth. As the Earth gets warmer, global precipitation and evaporation will both increase (roughly exponentially via the Clausius-Clapeyron relation). The existence of a glacier doesn't somehow mean that there is more water available in a certain location. The primary function that the glacier serves is as a water reservoir that can help smooth water consumption throughout a year; a dam, as TimG points out, can serve a similar function.

Global weather patterns tend to transfer moisture from air over oceans, to air over land. So some of the moisture of the precipitation that falls on, say Calgary, is coming from land (North America) and some of it is coming from ocean (Pacific Ocean). As temperatures increase, the ability for air to hold water increases roughly exponentially (Clausius Clapeyron relation). As a result, the rate of moisture transfer between oceans and continents increases. Thus continents will become on average wetter due to global warming, not drier, even after taking increased precipitation into account. This is why deserts were far more widespread during the last glacial maximum, and there was less rainforest.

[Bonam]

The above is correct. Nonetheless, those of us who enjoy outdoor recreation will be sad to see the glaciers go. There's nothing quite like walking on a glacier.

[On Guard for Thee]

Guess I have to spell it out for you.

In the long run, the amount of precipitation on Earth equals the amount of evaporation on Earth. As the Earth gets warmer, global precipitation and evaporation will both increase (roughly exponentially via the Clausius-Clapeyron relation). The existence of a glacier doesn't somehow mean that there is more water available in a certain location. The primary function that the glacier serves is as a water reservoir that can help smooth water consumption throughout a year; a dam, as TimG points out, can serve a similar function.

Global weather patterns tend to transfer moisture from air over oceans, to air over land. So some of the moisture of the precipitation that falls on, say Calgary, is coming from land (North America) and some of it is coming from ocean (Pacific Ocean). As temperatures increase, the ability for air to hold water increases roughly exponentially (Clausius Clapeyron relation). As a result, the rate of moisture transfer between oceans and continents increases. Thus continents will become on average wetter due to global warming, not drier, even after taking increased precipitation into account. This is why deserts were far more widespread during the last glacial maximum, and there was less rainforest.

You didnt need to be so long winded about it, although I get thats your schtick. But yep, all the water we have on this planet now it the same as it has always been. Well except for little bits that got spit out of the atmosphere during space exploration. The trouble is, we end up moving that water to places where we shouldnt, lie a golf course for instance. The trouble with depleting glaciers is essentially similar. The water from a melted glacier is ot lost, its just not flowing through the river anymore where the people who live there can get to it. Mind you they have likely already been displaced by the flooding as the glacier rapidly dissipates. And of course then there is the problem of SL rise. So all in all, trying to build dams to thwart this problem is for the most part, a waste of time in many areas.

[-1=e^ipi]

lie a golf course for instance.

If one of your main concerns about global warming is its effects of golf courses, then you really are out of touch with most of the people on this planet.

The water from a melted glacier is ot lost, its just not flowing through the river anymore where the people who live there can get to it.

Why not? Precipitation fell on the glacier in order to sustain the glacier. If the glacier melts, why would precipitation suddenly stop falling on the place where the glacier used to be?

And of course then there is the problem of SL rise.

Half a metre of sea level rise by the end of the century is hardly the end of the world. It is significant and should be considered in any evaluation on what should be done with respect to global warming, but please be realistic about the magnitude of the problem that sea level rise represents.

[On Guard for Thee]

If one of your main concerns about global warming is its effects of golf courses, then you really are out of touch with most of the people on this planet.

Why not? Precipitation fell on the glacier in order to sustain the glacier. If the glacier melts, why would precipitation suddenly stop falling on the place where the glacier used to be?

Half a metre of sea level rise by the end of the century is hardly the end of the world. It is significant and should be considered in any evaluation on what should be done with respect to global warming, but please be realistic about the magnitude of the problem that sea level rise represents.

Rain wouldnt stop falling, although it may be curtailed as GW increases evaporation which affects fresh water supplies. The main problem is though with glacial fed rivers without the glacier is the river level doesnt get topped up thru glacial melt in the dry seasons when people may depend on it most. Of course your half metre of SL rise by the end of the century is extremely optimistic. Greenland for instace is melting much faster than was previously anticipated, and there is enough water in there to adjust the SL by in excess of 20 feet.

[-1=e^ipi]

although it may be curtailed as GW increases evaporation which affects fresh water supplies.

Reread post #343. In equilibrium global precipitation equals global evaporation and warmer air can hold more moisture. The result is that global warming should make the continents overall wetter even after accounting for increased evaporation due to the increased moisture transfer from oceans to continents.

The main problem is though with glacial fed rivers without the glacier is the river level doesnt get topped up thru glacial melt in the dry seasons when people may depend on it most.

Solution: Build a dam. Even beavers understand this.

Of course your half metre of SL rise by the end of the century is extremely optimistic.

Half a metre isn't extremely optimistic. It is the mainstream scientific position. The IPCC's 5th assessment report, for example, suggests that sea level rise for the 21st century will be 26-82 cm.

Greenland for instace is melting much faster than was previously anticipated, and there is enough water in there to adjust the SL by in excess of 20 feet.

Yes, and a glacier doesn't melt overnight. It takes time, a long time (enthalpy of melting ice is 333.55 kJ/kg). The universe we live in appears to obey conservation of mass-energy.

Edited April 2, 2015 by -1=e^ipi

[On Guard for Thee]

Reread post #343. In equilibrium global precipitation equals global evaporation and warmer air can hold more moisture. The result is that global warming should make the continents overall wetter even after accounting for increased evaporation due to the increased moisture transfer from oceans to continents.

Solution: Build a dam. Even beavers understand this.

Half a metre isn't extremely optimistic. It is the mainstream scientific position. The IPCC's 5th assessment report, for example, suggests that sea level rise for the 21st century will be ~26 cm.

Yes, and a glacier doesn't melt overnight. It takes time, a long time (enthalpy of melting ice is 333.55 kJ/kg). The universe we live in appears to obey conservation of mass-energy.

And that time is shrinking as we warm the place up. Its funny you quote the IPCC, I thought you naysayers tried to pooh pooh their stuff. But if you go that route than you should know their latest report has SL rise at between 1 and 13 feet by end 2100. Your little beaver dam picture is cute of course, but those little guys are dealing with a regular seasonal flow. Not a series of floods followed by drought.

[-1=e^ipi]

I thought you naysayers

How am I a 'naysayer'? Although I understand why you try to label me as such. Maintaining the belief in a false dichotomy is one of the primary mechanisms by which alarmists maintain their absurd belief system. To acknowledge the existence of a position outside of the false dichotomy would be committing blasphemy.

But if you go that route than you should know their latest report has SL rise at between 1 and 13 feet by end 2100.

What's your source? Mine is http://www.ipcc.ch/pdf/assessment-report/ar5/wg1/WG1AR5_Chapter13_FINAL.pdf. This is the range of the 95% confidence intervals from RCP 2.6 to RCP 8.5.

The IPCC may be biased, but they are not orders of magnitude wrong. For example, they have a tendency to overstate climate sensitivity, they use GCM models such as CIMP5 (which gives a mean climate sensitivity estimate of ~3.2C) to make climate predictions, and they use emission scenarios that tend to overstate expected GHG levels over the century (RCP 8.5 is complete nonsense for example). However, they have to maintain some scientific accuracy and they do contribute to human knowledge on climate change.

Edited April 2, 2015 by -1=e^ipi