Moderated Global Warming Discussion

[batvette]

I'm struggling to understand what point you're trying to make with this. So there's some research which suggests that small variations in solar output may have a greater effect on the climate than previously thought. And? What has that got to do with the current warming?

Carbon dioxide is a greenhouse gas. Doubling the amount of it in the atmosphere produces a forcing resulting in an average global temperature rise of about 1 degree C. Positive feedbacks triggered by that forcing are estimated to result in a total temperature rise of about 3 degrees C per doubling of CO2. We have so far increased the amount of CO2 in the atmosphere by about 40% and at current rates of emission will have doubled it by the end of the century. Whatever other factors may or may not affect the climate does not alter these fundamental facts.

C02 isn't the most damaging of greenhouse gases. And in fact while increased C02 may raise the temperature, isn't it also true that rising temperatures force C02 to rise? What if the temperature rise was caused mainly by solar variation and the related release of methane gas naturally, and we're focusing on C02 being the primary cause of warming yet it is merely loosely associated with it?

Has anyone bothered to calculate the total methane release caused by what has been conceded to be a scientifically accepted consensus that solar variation forced "X" amount of warming in the last century?

 

[Reality Check]

C02 isn't the most damaging of greenhouse gases.

The fact is that CO2 is the second most abundant greenhouse gas.
The fact is that CO2 is the most damaging of the greenhouse gases. CO2 is not the only driver of climate but is the primary driver of current temperature changes

Stratospheric Water Vapour has increased due to oxidation of methane and had a slight warming effect of +0.07 Wm-2.
...
The radiative forcing from methane is +0.48 Wm-2.
...
The radiative forcing from CO2 is +1.66 Wm-2.

The fact is that increased CO2 does raise the temperature.

The global temperature rise was partially caused by solar variation in the last 100 years and not caused by solar variation in the last 32 years.

As for methane: See above and What is methane's contribution to global warming?

While methane is a more potent greenhouse gas than CO2, there is over 200 times more CO2 in the atmosphere. Hence the amount of warming methane contributes is 28% of the warming CO2 contributes.

 

[batvette]

no statistical correlation between solar cycles global temperatures has ever been identified. (There probably is one, just to small to rise above the noise)


One of the Scientists cited in that article was the lead author of the paper I linked earlier which showed that none of the current temperature change is attributable to solar activity.

Then you position and theirs is to be considered fringe far outside the consensus and dismissed from the scientific debate. As another user just replied the scientific position is that 15% (or more) of the current warming can be blamed on solar variation.

I mean, shouldn't you be asserting this to Trakar who said:

They may well be a part of the 15% of total solar forcing signature that climate science observes and recognizes in the current climate change picture, particularly in evidence in the climate signal in the first half of last century.

And I'm pretty sure I have seen figures surpassing that 15- as high as 40% and even a few who said it was the most significant factor-as I have seen some scientists claiming that solar variation has no influence.

So if there isn't even a consensus on this board, nor in science- but the continued insistence is that man's doing it and anything else is inconsequential- how is that an objective, scientific conclusion we're pursuing?

Seems like the solar variation aspect has one area of common ground: Science begrudgingly must concede its role, but minimize it or obscure any study of it when it raises its ugly head. Science only comes together as a consensus to oppose those who question the human role, but when such a wide disparity exists on the solar role, it is hardly reassuring that the conclusion is driven by objective intent.

 

[Pixel42]

C02 isn't the most damaging of greenhouse gases.

True. The increase in CO2 is the biggest single contributor to the recent warming, but that may change going forward.

And in fact while increased C02 may raise the temperature, isn't it also true that rising temperatures force C02 to rise?

Eventually, yes. It's one of many positive feedbacks that amplify the effect of any forcing. In the case of the Milankovich cycles it takes between 500 and 1000 years for the initial forcing to warm the oceans and permafrost sufficiently for them to become net sources of CO2. Currently the oceans are still acting as a net sink of the CO2 we've put into the atmosphere, it's estimated they've absorbed about a third of it. The resulting acidification of the oceans is causing problems of it's own.

http://en.wikipedia.org/wiki/Ocean_acidification

What if the temperature rise was caused mainly by solar variation and the related release of methane gas naturally, and we're focusing on C02 being the primary cause of warming yet it is merely loosely associated with it?

Solar variation is neither a big enough nor a prolonged enough forcing to initiate significant positive feedbacks, not on the timescales we're talking about anyway. There's an underlying trend of rising solar radiation that will eventually fry the planet, but that will take billions of years. Isotopic analysis of the CO2 in the atmosphere shows that the 40% increase that has appeared in the last century or so has come from fossil fuels sequestered millions of years ago, not from the oceans and permafrost.

Has anyone bothered to calculate the total methane release caused by what has been conceded to be a scientifically accepted consensus that solar variation forced "X" amount of warming in the last century?

Climatologists calculate the effect of all known forcings and feedbacks. It's what they do.

 

[DC]

C02 isn't the most damaging of greenhouse gases. And in fact while increased C02 may raise the temperature, isn't it also true that rising temperatures force C02 to rise? What if the temperature rise was caused mainly by solar variation and the related release of methane gas naturally, and we're focusing on C02 being the primary cause of warming yet it is merely loosely associated with it?

Has anyone bothered to calculate the total methane release caused by what has been conceded to be a scientifically accepted consensus that solar variation forced "X" amount of warming in the last century?

many studies have quantified the forcings and the the amount of GHG's etc etc. why do you ask People on an online Forum? why do you not do some reading on the Topic? and learn what scientists actually did Research already and what they found out. the IPCC AR4 is a good starting Point.

 

[lomiller]

This is a nonsensical answer to the question and this confusion is not a rebuttal to the point, which is that we can establish what should be considered "normal" solar output over the 400 year period through averaging each cycle's sunspot activity. We should compare each cycle against the norm to ascertain whether we should expect warming or cooling over that cycle- not merely if the cycle indicates slightly less activity than the previous one or two.

Your inability to make sense of the facts is irrelevant. Your notion that temperatures should rise as long as long as solar activity is above some arbitrary “400 year average” is complete nonsense that shows an inability to understand basic physics.

AGAIN, the response time of the earth to a change in solar activity is on the order of ~20 years. If solar activity increases the earth warms for a decade or two then the warming stops because a new equilibrium has been reached. If the activity goes back down the earth cools for a decade or two then the cooling stops, again because equilibrium has been reached.

In either case the observed or suspected change in solar activity are not large enough to account for more than a few tenths of a degree change in global temperatures.

Can you expand upon the reference to the first half of the last century regarding "climate signal"? What do you present is the consensus regarding the trends in temperature vs solar activity (overall output theoretically correlated to sunspot activity) in that period?

Please read the paper I already linked. It gives you the climate signals for the major forcing, including solar. Per what everyone here is already telling you, and what 97% of publishing climate scientists say, solar activity plays a negligible role in warming post 1950.

Whatever the exact figure, is this forcing calculated merely by the suns actual output? Or does it also take into consideration the expected residual effect of natural greenhouse gas releases in the form of methane from melting polar ice?

Slow feedbacks like this are not usually included in short term sensitivity estimates whether the forcing is solar or greenhouse initiated. Faster feedbacks like water vapor are included

When looking at past climate over longer periods these will get built in, but often in the form of parameters like the known atmospheric CO2 concentrations or ice coverage. If modeled the models will need to conform to the know values as well.

C02 isn't the most damaging of greenhouse gases.

CO2 is the largest positive forcing by a factor of 2. Methane is second, but this is also anthropogenic in origin.

And in fact while increased C02 may raise the temperature, isn't it also true that rising temperatures force C02 to rise? What if the temperature rise was caused mainly by solar variation and the related release of methane gas naturally,

Current CO2 and Methane increases are directly attributable to human activity. The oceans and biosphere continue to take CO2 out of the atmosphere and as yet have actually offset, rather than contributed, to the rise in atmospheric CO2. This probably can’t continue indefinably. At some point warming oceans will add CO2 to the atmosphere instead of removing it.

we're focusing on C02 being the primary cause of warming yet it is merely loosely associated with it?

CO2 and other anthropogenic greenhouse gasses ARE the primary, and really the only major cause of current warming. CO2 is also the connecting factor that allows small orbital wobbles to cause glaciers to advance or retreat. It is more than just “loosely associates” with climate change it’s one of the essential elements for explaining the climate history of the earth.

Has anyone bothered to calculate the total methane release caused by what has been conceded to be a scientifically accepted consensus that solar variation forced "X" amount of warming in the last century?

Again, Methane in the atmosphere breaks down within a few decades so any that was released in response to solar variation is long gone. How much Methane is or could be released in response to warming is studied quite intensively but so far there is little evidence that this is making significant contributions to atmospheric Methane.

 

[ArmoredDragon]

65 million years ago, CO2 was 3,000 parts per million compared to the present 375. Temperatures were much warmer, which made rainfall (and fresh water) more plentiful. Since there was more atmospheric CO2, plants also required less water. The climate was not hostile at all to macro-scale life, as this is the period of meter-long dragonflies and very large animals such as dinosaurs.

Patrick Moore, cofounder of greenpeace, says global warming increases the availability of arable land as well as bio-fertility.

The IPCC claims that CO2 levels even slightly above what we are at now will acidify the ocean to the point that it will have very damaging ecological consequences, but they were wrong:

http://www.co2science.org/articles/V14/N18/B3.php

Bottom line: we're not in any imminent danger as a result of a climate shift; natural or man made.

 

[ArmoredDragon]

Minor correction to my last post: 165 million.

 

[CapelDodger]

This is a nonsensical answer to the question and this confusion is not a rebuttal to the point, which is that we can establish what should be considered "normal" solar output over the 400 year period through averaging each cycle's sunspot activity. We should compare each cycle against the norm to ascertain whether we should expect warming or cooling over that cycle- not merely if the cycle indicates slightly less activity than the previous one or two.

Again I ask why you think 400 years defines the norm. Also again, I ask by what mechanism you think the Maunder Minimum is affecting climate now, centuries later.

Also also again I will point out what you're missing, which is that a warmer world loses heat more rapidly than cooler one so any change in solar activity is soon matched (via the induced warming) by increased heat loss, and warming stops. The energy budget is balanced within at most decades, so the only norm worth considering is the norm on that timescale.

Solar output over the last fifty years at least has not changed significantly. During that time the climate has warmed considerably. The former is therefore not the cause of the latter.

 

[CapelDodger]

C02 isn't the most damaging of greenhouse gases. And in fact while increased C02 may raise the temperature, isn't it also true that rising temperatures force C02 to rise? What if the temperature rise was caused mainly by solar variation and the related release of methane gas naturally, and we're focusing on C02 being the primary cause of warming yet it is merely loosely associated with it?

Has anyone bothered to calculate the total methane release caused by what has been conceded to be a scientifically accepted consensus that solar variation forced "X" amount of warming in the last century?

The amount of methane in the atmosphere has been recorded for many decades and it isn't what's causing the problem. It is possible to run the numbers. The problem is being caused by CO₂.

This is not mysterious. Everything you've thought of professionals have already thought of and investigated, and there are people who post here who have kept up with the findings. There is no fog to conceal the nasty reality except the fog of ignorance.

To actually examine your thoughts here, the direct solar influence on permafrost is unlikely to be greater than the direct influence of AGW given that half the time the Sun is set, whereas the greenhouse effect never sleeps. Unusual degradation of permafrost has only been noted since about 2005, long after any 20thCE solar increase will have been assimilated but well within the assimilation term of AGW. So no, I really don't think your ideas are going to pan out.

 

[Haig]

C02 isn't the most damaging of greenhouse gases. And in fact while increased C02 may raise the temperature, isn't it also true that rising temperatures force C02 to rise?

Good points. Water vapor is the most abundant of the greenhouse gasses as well as being the most effective at keeping the planet warm so it can be argued it's the most damaging too but ... However, on a "per molecule" basis, many other molecules are more effective greenhouse gases. The top greenhouse gas, as reported by the Envirommental Protection Agency, is methane.This silent odorless gas is 21 times more effective in trapping in heat in the atmosphere. In recent studies reported by the EPA, one of the leading contributors of methane into the environment was natural animal emissions; raising the question of whether or not global warming is man-made problem. Yet the warmists focus on Co2 when it follows the temperature rise not leads it.

What if the temperature rise was caused mainly by solar variation and the related release of methane gas naturally, and we're focusing on C02 being the primary cause of warming yet it is merely loosely associated with it?

So if it's mainly the Sun there is not much we can do about it! What? some are saying tax sunshine or the lack of it?

 

[DC]

Good points. Water vapor is the most abundant of the greenhouse gasses as well as being the most effective at keeping the planet warm so it can be argued it's the most damaging too but ... However, on a "per molecule" basis, many other molecules are more effective greenhouse gases. The top greenhouse gas, as reported by the Envirommental Protection Agency, is methane.This silent odorless gas is 21 times more effective in trapping in heat in the atmosphere. In recent studies reported by the EPA, one of the leading contributors of methane into the environment was natural animal emissions; raising the question of whether or not global warming is man-made problem. Yet the warmists focus on Co2 when it follows the temperature rise not leads it.

So if it's mainly the Sun there is not much we can do about it! What? some are saying tax sunshine or the lack of it?

and your evidence that CO2 is not leading the warming but follwing it?
and pls dont shame yourself in bringing up that old debunked myth about the 800 year lag disptoving CO2 leads.
what is your evidence.

 

[marplots]

65 million years ago, CO2 was 3,000 parts per million compared to the present 375. Temperatures were much warmer, which made rainfall (and fresh water) more plentiful. Since there was more atmospheric CO2, plants also required less water. The climate was not hostile at all to macro-scale life, as this is the period of meter-long dragonflies and very large animals such as dinosaurs.

(Some snipped here)

Bottom line: we're not in any imminent danger as a result of a climate shift; natural or man made.

I think you make a very good case for things being much more dangerous for man. Remember, we occupy a niche, despite our ability to modify our immediate surroundings. I very much fear the rise of other organisms capable of exploiting the environment you describe.

Let me remind you of the power of mosquitoes bearing yellow fever and malaria once had and the current problem with the tse-tse:

(Wiki)Tsetse control efforts have been undertaken throughout the African continent, but long-term, sustainable control has rarely been achieved. Tsetse control efforts invariably are tied to the complex problems of poverty, health, politics, and violence that have proved so disastrous for the African people.

We are the current champs of exploiting the climate as it is. Will we retain the title under the new rules?

 

[Reality Check]

Water vapor is the most abundant of the greenhouse gasses as well as being the most effective at keeping the planet warm so it can be argued it's the most damaging too but ...

But ... water vapor is not the most abundant of the greenhouse gasses !
What is methane's contribution to global warming?

While methane is a more potent greenhouse gas than CO2, there is over 200 times more CO2 in the atmosphere. Hence the amount of warming methane contributes is 28% of the warming CO2 contributes.

The warmists focus on Co2 when it follows the temperature rise not leads it.

There may be deluded "warmists" out there that that focus only on CO2.
But they (like you) are wrong - CO2 levels do not always come after temperature rise.
CO2 lags temperature - what does it mean?

When the Earth comes out of an ice age, the warming is not initiated by CO2 but by changes in the Earth's orbit. The warming causes the oceans to release CO2. The CO2 amplifies the warming and mixes through the atmosphere, spreading warming throughout the planet. So CO2 causes warming AND rising temperature causes CO2 rise. Overall, about 90% of the global warming occurs after the CO2 increase.

What does past climate change tell us about global warming?

Natural climate change in the past proves that climate is sensitive to an energy imbalance. If the planet accumulates heat, global temperatures will go up. Currently, CO2 is imposing an energy imbalance due to the enhanced greenhouse effect. Past climate change actually provides evidence for our climate's sensitivity to CO2.

A little thing called the greenhouse effect means that after CO2 levels rise, temperature rises (given that other climate drivers are constant). We have seen this happen over the last 100 years (with increasing solar output) and over the last 35 years (with constant solar output).

So if it's mainly the Sun there is not much we can do about it!

Luckily it is not mainly the Sun so there is little point in indulging in fantasies that it is the Sun. It might make good science fiction - it is not good science.
Solar activity & climate: is the sun causing global warming?

In the last 35 years of global warming, the sun has shown a slight cooling trend. Sun and climate have been going in opposite directions. In the past century, the Sun can explain some of the increase in global temperatures, but a relatively small amount.

The overwhelming evidence that it is CO2 that is the main driver of global warming means that we can do something about it, e.g. reduce our emissions of CO2.

 

[uke2se]

So if it's mainly the Sun there is not much we can do about it! What? some are saying tax sunshine or the lack of it?

It isn't mainly the sun. This has been confirmed scientifically. Once again: The sun is not responsible for recent warming.

 

[Megalodon]

Patrick Moore, cofounder of greenpeace, says global warming increases the availability of arable land as well as bio-fertility.

That and a couple of bucks will get him a cup of coffee... where are the studies? Also, if climate is moving polewards, in a sphere, where does he get the increased availability of land? Or the soil, for that matter?

The IPCC claims that CO2 levels even slightly above what we are at now will acidify the ocean to the point that it will have very damaging ecological consequences, but they were wrong:

One paper, regarding one species, and you think the IPCC was wrong? I'll raise you this one

http://www.plosone.org/article/info:doi/10.1371/journal.pone.0050865

See, the little critters can still calcify (depending on who you mean by "little critters"), but now they get to starve due to a slowed carbon pump.

Bottom line: we're not in any imminent danger[...]

So you say. I say the opposite, and I actually study ocean acidification. The overwhelming majority of scientists studying OA agree with me. Forgive me if I disregard your opinion.

[...]as a result of a climate shift; natural or man made.

The numbers are in, and there's nothing natural about the climate shift. But deniers will keep grasping at that straw, even as forecast events unfold around them.

 

[Trakar]

This is a nonsensical answer to the question and this confusion is not a rebuttal to the point, which is that we can establish what should be considered "normal" solar output over the 400 year period through averaging each cycle's sunspot activity. We should compare each cycle against the norm to ascertain whether we should expect warming or cooling over that cycle- not merely if the cycle indicates slightly less activity than the previous one or two.

the average or the mean? what is significant about 400 years? has the mechanism responsible for sunspot activity been stable and consistent over the last 400 years? what evidence leads you to believe that sunspot activity has any relationship to climate temperature? by what interaction do sunspots generate a warming or cooling climate?


Nothing you have suggested is unknown or untested by climate science studies and investigations over the last century or two. In all of that research no compelling evidence has been put forward supporting the idea that sunspots are more than weakly correlated to any measurable global climate shifting. Likewise, over the same timeframe, accumulating supportive evidences have increasingly confirmed and established the nature and physics of atmospheric GHGs and their strong, measurable impacts upon the planetary climate.

 

[Trakar]

Can you expand upon the reference to the first half of the last century regarding "climate signal"? What do you present is the consensus regarding the trends in temperature vs solar activity (overall output theoretically correlated to sunspot activity) in that period?

As far as I'm aware, there has never been any compelling, strong correlation between sunspot activity and global climate or temperature trends, primarily because sunspot activity in the current phase of our star's life has such a low-level, and short-term impact on solar output. As for the Sun's overall impact on modern climate change, it isn't that the Sun's output has changed significantly over the last few centuries, but rather that GHG's role in climate has increased since human activities began adding large amounts of previously sequestered carbon back into the active carbon cycle of our planet.

So while the Sun's minor cycles of variation accounted for nearly half of all shorter term climate variation in the early decades of the last century, and GHGs only counted for a small portion of short-term climate variation at that time, the massive and accelerating increases in global industrialization that occurred since WWI have dramatically increased the amount of CO2 in our atmosphere to the degree that by mid-century GHG climate forcing had become much larger than the rather steady and stable solar influences.

Currently total solar influences have amounted to a variation that is a very small fraction of a Watt (<0.1) per square meter over the last 50 years, by the same token, GHG influences have added nearly 3Watts per square meter over the same time period.

Secondly I've seen various accepted figures for the role of the sun in current trends from 15 percent to as high as 40 percent. Whatever the exact figure, is this forcing calculated merely by the suns actual output? Or does it also take into consideration the expected residual effect of natural greenhouse gas releases in the form of methane from melting polar ice?

Climate sensitivity measurements are inclusive of all known positive and negative feedback interactions, both short-term and long-term. The 15% I've spoken of is in reference to the forcing attributable to total solar output variations in the current climate signal.
(National Academies of Science - "The Effects of Solar Variability on Earth's Climate: A Workshop Report" - http://www.nap.edu/catalog.php?record_id=13519)

 

[Corsair 115]

Minor correction to my last post: 165 million.

165 million year ago there weren't seven billion human beings around who had deforested vast swaths of the Earth's surface to may way for towns, cities, farms, roads, highways, factories, airports, etc. Continental positions were also very different.

 

[Trakar]

C02 isn't the most damaging of greenhouse gases. And in fact while increased C02 may raise the temperature, isn't it also true that rising temperatures force C02 to rise? What if the temperature rise was caused mainly by solar variation and the related release of methane gas naturally, and we're focusing on C02 being the primary cause of warming yet it is merely loosely associated with it?

Has anyone bothered to calculate the total methane release caused by what has been conceded to be a scientifically accepted consensus that solar variation forced "X" amount of warming in the last century?

The primary method by which solar radiation forces short-term climate change (read as over periods of 1000s of years) in the current stellar stage of evolution, is through natural shifts in the condition and orientation of our planet's orbit around the sun. These are also known as the Milankovitch cycles after their discoverer, astrophysicist Milutin Milankovitch. These aren't due to increase/decrease changes in the Sun, rather they are due to small changes in the levels of solar irradiation the planet intercepts in different orbital configurations about the Sun.

While at comparable levels, Methane is a very strong GHG, it is a much smaller fraction of our atmosphere than CO2 and generally (under current conditions) breaks down to CO2 and HOH (water vapor) in atmospheric interactions.

CO2 = ~0.04% of Atmosphere
CH4 = ~0.00017% of Atmosphere

so while Methane is potentially some 20x stronger GHG, there is more than 200x more CO2 than Methane in our atmosphere.