General AGW discussion thread

[dgruss23]

Originally Posted by lomiller1

What you aren’t mentioning is that for this paper to be correct climate sensitivity need to be much higher meaning we will get far more CO2 warming then anyone is currently predicting. Essentially they are saying small forcing create enormous warming but that it takes so long we’ve felt very little of the CO2 induced warming and are still working on the 0.1% increases in solar intensity from 80 years ago.

Could you clarify where you are getting this from? Climate sensitivity is discussed in paragraph 17 of the paper, but not as you're describing. What they pointed out in that paragraph is that the Lean 2005 TSI reconstruction would suggest an almost 3x greater climate sensitivity to solar changes than the earlier reconstructions.

By that they mean it increase in the early part of the 20th century then stayed about the same for the last 60 years.

No, actually that is not quite the case. The sun spiked up in activity between 1900 and 1940 as can be seen in figure 2. Usoskin et al describe this as "unique" during the last 1150 years. However if you look at the remainder of the 20th century solar activity in figure 2 you can see that there was a drop in solar activity between ~1940 and ~1975. This drop in solar activity corresponds with a cooling trend in the temperature records that is well established and not disputed. This cooling trend of course happened even as CO2 continued to increase. Then after 1970 toward the present you can see the solar activity begin to spike back up again -- and temperatures have begun to increase since the 1970's.

The 1940-1970 cooling that corresponds with decreasing solar activity is support for an important solar influence on climate even on smaller time scales. Why was the climate cooling between 1940 and 1970 as CO2 increased, if CO2 is such an important climate forcer?

The bulk of the research shoes 80% - 90% of 20th century warming is manmade, the IPCC is simply quoting the current research. Scaffette is generally rejected by climate scientists because it implies much higher levels of greenhouse warming.

80-90% - No. That significantly underestimates studies on the solar influence.

Incorrect. The correlation on that scale is almost entirely orbital effects that redistribute but don’t significantly change the amount of solar energy the earth receives.

There are additional solar effects beyond TSI variations. See for example Sharma's work and here too . He finds that variations in solar activity may be responsible for the glacial/interglacial cycles. In order for that to occur the solar influence has to be more than just direct TSI variations. There are also indirect solar effects hypothesized to be associated with the solar wind moderating cosmic ray flux in the upper atmosphere.

Christl et al (2004) also found evidence for a relationship between cosmic ray flux and the Earth's climate on the same timescale as Sharma.

On those large scales we're talking about solar influence related to internal variations in the solar activity level, not orbital variations of the Earth about the Sun, which I would agree are not likely to be significant in the Earth's climate.

[dgruss23]

Originally Posted by lomiller1

Just a few more notes on solar vs greenhouse warming

Solar induced warming warms the upper atmosphere, greenhouse warming cools it. The upper atmosphere is cooling.

Solar induced warming causes a stronger daytime signal, greenhouse warming is stronger at night. Nighttime temperatures are currently warming more then daytime temperatures

Solar warming is more prominent at lower latitudes, greenhouse warming more prominent at higher latitudes. Current warming is more pronounced at higher latitudes.

Solar warming creates more summertime highs, greenhouse warming creates fewer wintertime lows. We are experiencing a marked decrease in wintertime los worldwide, but no increase in summertime highs.

References providing these predictions please.

[lomiller1]

Originally Posted by princemyheart

"Just a few more notes on solar vs greenhouse warming"

I need some help here. Surely the source of both is solar? Isn't the 'greenhouse' effect radiated heat from the Earth's surface trapped by the atmosphere?

Looks like I've got some learning to do.

The energy is almost all solar but temperature change is a function of both incoming and outgoing energy. This means the planet can warm for two possible reasons, more energy comes into the atmosphere or less energy gets out. The greenhouse effect of course acts to reduce the amount of energy that escapes the atmosphere (at any given planetary temperature.)

[dgruss23]

Originally Posted by Ronald Brak

If you read that paper you would see that Scafetta and West attribute 25-35% of the warming from 1980-2004 to the sun, so there is no disagreement. But even that conclusion is not supported by direct measurements of solar activity which indicate no trend in solar activity over that period.

Scafetta and West say the following (JGR, November 3,2007):

Originally Posted by Scafetta and West

Figure 6 shows the comparison between the two NH temperature reconstructions shown in Figure 1 and the phenomenological solar temperature signatures obtained with the TSI proxy reconstructions corrected with the ACRIM TSI satellite composite since 1980, as shown in Figure 3. By assuming ACRIM, the solar activity has an increasing trend during the second half of the 20th century. ... By assuming MOBERG05, the Sun is responsible for ~0.45K (or 56%) with LEAN2000 and ~0.55K (or 69%) with WANG2005 of the warming that occurred from 1900 to 2005, and ~ 0.15K (or 20%) with Lean2000 nad DeltaT=0.25K (or 42%) with WANG2005 of the warming that occurred since 1950. (The estimates might present an error of 20%).

In this article Scafetta and West point out that between 2002 and 2007 the planet showed a cooling trend as the Sun went from the 2001 solar max to the 2007 solar min. And isn't 2008 on pace to be the coolest year of this decade? And isn't the onset of increased solar activity delayed with this cycle?

In addition Scafetta and west argue that the IPCC has significantly underestimated the solar influence and therefore significantly overestimated the anthropogenic influence on climate.

My point in all this is that contrary to what some were saying at the beginning of this thread, there is evidence for a significant solar influence on climate - and that evidence has been uncovered on all timescales studied.

It's right here:

http://climateprogress.org/2008/12/1...850/#more-4423

Thank You!

[dgruss23]

Originally Posted by mugaliens

I see a lot of debate concerning direct radiation, but little to nothing about secondary effects, which may be more of a multiplier of radiation than having any direct effects.

Yes, this is a common misunderstanding. It is well established that variations in the amount of energy the Sun puts out alone, cannot explain climate change past or present. However, indirect solar effects such as moderating the cosmic ray flux, may have an even larger impact on climate than the variations in solar energy.

[lomiller1]

Originally Posted by dgruss23

In this article Scafetta and West point out that between 2002 and 2007 the planet showed a cooling trend as the Sun went from the 2001 solar max to the 2007 solar min.

The issue of cherry picking a short time period to show a “trend” aside, how can they assume it takes 70 years for a warming of the sun to show up, but less then 5 for a solar minimum to show up?

Originally Posted by dgruss23

And isn't 2008 on pace to be the coolest year of this decade? And isn't the onset of increased solar activity delayed with this cycle?

No one has ever found a direct, statistically valid correlation between the solar cycle and global temperate, primarily because the energy variation across the solar cycle is miniscule in comparison to what it takes to heat/cool the planet.

BTW "coolest year of this decade" is still warmer then any year prior to 2000 save 1998.

Originally Posted by dgruss23

However, indirect solar effects such as moderating the cosmic ray flux, may have an even larger impact on climate than the variations in solar energy.

that's a topic for ATM

[Ara Pacis]

My understanding is that an overabundance of CO2 can, through the greenhouse effect, increase whatever natural heat retention ability of the earth there is past a tipping point, where other processes start to come into play and that some of these processes can also enhance the natural heat retention ability of the earth.

[ravens_cry]

One example is the basic scientific fact that gases, unlike solids, dissolve less readily in warm water then cool water. What this means is that dissolved CO2 in the worlds oceans, will start to be released as the temperatures increase from man released CO2. While I doubt we could say, create another Venus from our actions, it would certainly change the world as we know it. Another thing is that the polar ice reflects significant amounts of sunlight away from the earth because of it's high albedo. With that gone, and from the melt of permafrosts, starting the decay of long dead biomass, it is more then just the CO2 from fossil fuels alone.

[Ari Jokimaki]

Lean & Rind (2008) report only 10 % for the solar forcing contribution of the warming in the last 100 years.

[ArgoNavis]

Originally Posted by lomiller1

Just a few more notes on solar vs greenhouse warming.....Solar warming is more prominent at lower latitudes, greenhouse warming more prominent at higher latitudes. Current warming is more pronounced at higher latitudes.....

Drivel.

Both satellite and land based temperature measures indicate that the Antarctica has not warmed at all.

http://4.bp.blogspot.com/_gPVBk-7hxL...SS_october.gif

and

http://www.environment.gov.au/soe/20...464/index.html


Unless you think Antarctica is not a "higher latitude".

Please feel free to provide evidence for the rest of your assertions.

[Argos]

Originally Posted by mugaliens

This is a government website, not a woo-woo site. It's the US Senate Committee on Environment & Public Works.

Does not impress me at all.

[Ara Pacis]

Originally Posted by ArgoNavis

Drivel.

Both satellite and land based temperature measures indicate that the Antarctica has not warmed at all.

http://4.bp.blogspot.com/_gPVBk-7hxL...SS_october.gif

and

http://www.environment.gov.au/soe/20...464/index.html


Unless you think Antarctica is not a "higher latitude".

Please feel free to provide evidence for the rest of your assertions.

What happened to all that ice in the WAIS?

[lomiller1]

Originally Posted by dgruss23

Could you clarify where you are getting this from? Climate sensitivity is discussed in paragraph 17 of the paper, but not as you're describing. What they pointed out in that paragraph is that the Lean 2005 TSI reconstruction would suggest an almost 3x greater climate sensitivity to solar changes than the earlier reconstructions.

The short version is that climate sensitivity is the same whether you increase the amount of energy entering the atmosphere of decrease the amount that can exit the atmosphere. This means that if you assume a higher climate sensitivity for solar activity you are also assuming a higher sensitivity to greenhouse gasses.

Longer version is that there is no such thing as “sensitivity to solar activity”, climate sensitivity is to the energy imbalance at the top of the atmosphere, whatever it’s cause.

Forcing like changes in greenhouse gasses or solar activity change are rate of change of energy. As long as more energy flows into the system it will continue to warm. Clearly an increase in solar activity would not cause the earth to warm indefinitely. As surface temperature rises so does the amount of blackbody radiation the earth is generating. At some point this outgoing blackbody radiation matches the increased solar activity and the warming stops. Climate sensitivity is a measure of the amount of temperature rise it takes for BB radiation to offset the other change.

This process occurs reacts to energy imbalance at the top of the atmosphere so it doesn’t matter whether that energy imbalance comes from greenhouse gasses reducing the energy that escapes or increased solar activity increasing the amount of energy the earth receives.

Originally Posted by dgruss23

No, actually that is not quite the case. The sun spiked up in activity between 1900 and 1940 as can be seen in figure 2.

It’s now 2009, meaning there has been no increase in solar activity for 70 years, and we are 110 years out from when solar activity began to pick up. Again you can’t have it take 70-100 years for an increase in solar activity to show and still expect a decrease in solar activity to show up in 2 years.

Originally Posted by dgruss23

However if you look at the remainder of the 20th century solar activity in figure 2 you can see that there was a drop in solar activity between ~1940 and ~1975. This drop in solar activity corresponds with a cooling trend in the temperature records that is well established and not disputed.

There is no “1940 – 1975 cooling trend” Global temperatures spiked in the late 30’s then decreased rapidly during WWII. They then stayed about the same for the next 2 decades. Changes in aerosol production due to human economic activity nicely explains this.

Temperature response to aerosols are faster then CO2 but because they don’t stay around as long CO2 has a greater long term effect. If you build a new coal plant it takes ~20 years before the warming effect of CO2 overcomes the cooling effects of aerosols when a near. During the 30’s when industrial production was shutting down and aerosol output dropped temperature spiked rapidly, during WWII when industrial production spiked global temperatures dropped.

[lomiller1]

Originally Posted by ArgoNavis

Drivel.

Both satellite and land based temperature measures indicate that the Antarctica has not warmed at all.

http://4.bp.blogspot.com/_gPVBk-7hxL...SS_october.gif

and

http://www.environment.gov.au/soe/20...464/index.html


Unless you think Antarctica is not a "higher latitude".

Please feel free to provide evidence for the rest of your assertions.

You are correct, I should have specified the Artic and western Antarctica as central Antarctica is driven by a whole different set of forces. Other then that you post is utter nonsense and a clear attempt to divert attention from the real questions.

[ArgoNavis]

Originally Posted by lomiller1

You are correct, I should have specified the Artic and western Antarctica as central Antarctica is driven by a whole different set of forces. Other then that you post is utter nonsense and a clear attempt to divert attention from the real questions.

Not at all.

Here is a better graphic. Please explain how the higher lattitudes are experiencing warming.

The rest of yout post is drivel too. You clearly have no real evidence or data to support these assertions.

I should know better than to argue than to try and argue with a religious fanatic who believes in the biggest scientific fraud in history.

[lomiller1]

Originally Posted by ArgoNavis

Not at all.

Here is a better graphic. Please explain how the higher lattitudes are experiencing warming.

What exactly is temperature for Dec 17 2008 supposed to tell us about the long term temperature trend? It’s not even anomaly for gods sake, but the current temp in deg K, so of course the poles are cooler…

[lomiller1]

Originally Posted by Tesarra

Any economists around? I've always been curious about the whole "it'll destroy the economy" argument against governments taking action on global warming.

Japan, the UK, France and Germany already produce less then ½ the CO2 per capita as the US, Canada or Australia. Clearly there are some significant CO2 reductions that can be made with little or no economic impact.

[ToSeek]

Originally Posted by ArgoNavis

I should know better than to argue than to try and argue with a religious fanatic who believes in the biggest scientific fraud in history.

To quote Rule 2 of this forum, "Attack the ideas, not the person(s) presenting them. If you've got concerns with what someone is saying, feel free dismantle their arguments, but do not resort to ad hominem or personal attacks." This is out of line.

[Ronald Brak]

Any economists around? I've always been curious about the whole "it'll destroy the economy" argument against governments taking action on global warming.

Taking action on global warming will not destroy the economy. Cutting Australian CO2 emissions by 80% over the next 42 years will cost an estimated total of 2.7% of GDP. That's about one years growth out of 42 years. This is something that we can certainly afford to do. And it's not even that we will be 2.7% poorer as we will benefit from suffering less economic damage resulting from climate change. Reducing greenhouse gas emissions is a sensible way to protect our economy.

[Ara Pacis]

Originally Posted by Tesarra

Isn't macro-economics a zero-sum game?

No. Good leadership can create wealth, bad leadership can destroy it. An exchange need no be win-lose, it can be win-win.

[geonuc]

Originally Posted by Argos

Does not impress me at all.

Me neither, given that the page is actually a blog controlled by one member of the committee. It doesn't represent the views of the Senate committee as a whole. Not even close.

[Swift]

Originally Posted by Tesarra

So, a poorly formulated plan to reduce CO₂ emissions could end up sapping at least a portion of GDP off to some never never land of government waste and/or corruption.

But a poorly formulated plan to do just about anything could do that.

[Warren Platts]

Originally Posted by geonuc

I'm inclined to urge the next US administration to install Swift as EPA administrator. What he says makes sense.

There are some things we - the US in particular - could be doing to reduce emissions of greenhouse gasses that are sensible even if the models are not entirely accurate. Doing more to reduce gasoline consumption would help, for example.

Yeah, we could mismanage the money supply by keeping interest rates artificially low, fix the tax structure to encourage people to stay perpetually in hoc on their houses, and thus cause a housing bubble. Then when the American housing bubble bursts, it will induce a worldwide depression that will dramatically reduce global fossil fuel consumption, and thereby reduce global CO₂ emissions everywhere!

[Ara Pacis]

Originally Posted by Warren Platts

Yeah, we could mismanage the money supply by keeping interest rates artificially low, fix the tax structure to encourage people to stay perpetually in hoc on their houses, and thus cause a housing bubble. Then when the American housing bubble bursts, it will induce a worldwide depression that will dramatically reduce global fossil fuel consumption, and thereby reduce global CO₂ emissions everywhere!

That plan's so crazy... it. might. just. work.

[ravens_cry]

Or we could bomb ourselves back to the Stone Ages, and never use fire again.
That would do it too.

[speedfreek]

What do we think of the recent update at Global Warming Petition Project then? I would have assumed it had been discussed here before, but I couldn't find any references to it using the forum search.

[Torsten]

If you google search the site (top of the page) for "oism" ("oregon institute of science and medicine"), you'll find old discussion on it.

[parejkoj]

Originally Posted by speedfreek

What do we think of the recent update at Global Warming Petition Project then? I would have assumed it had been discussed here before, but I couldn't find any references to it using the forum search.

That seems roughly as irrelevant as the list quoted in the top of this article. Have the people who signed that "petition" published in the relevant journals? This is all an attempt at a response to Naomi Oreske's Science article on consensus. Unfortunately, petitions and lists are no replacement for actual research.

See Gavin's reply to this comment on realclimate.org for more on Inhofe's list.

[Kebsis]

I remember reading that the average given for a particular years temp are actually a composite of several averages. Is this true?

[mugaliens]

Originally Posted by lomiller1

No one has ever found a direct, statistically valid correlation between the solar cycle and global temperate, primarily because the energy variation across the solar cycle is miniscule in comparison to what it takes to heat/cool the planet.

Perhaps not with the solar cycle, but certainly with sunspots. It's not perfect (what correlation is?), to be sure, but it's certainly there.

I find it interesting that the more recent the time frame, the stronger the correlation. Indeed, priot to about 4,500 years ago, it apparently flips, with there being a distinct negative correlation.

I wonder what's up with that?

Still, this much closer examination of the last 400 years (C-14 indications of temps in this graph) is quite telling.