Stan wrote:
Solar collectors are darker than the darkest black, as they absorb and convert and move energy never coming into thermal equilibrium and never re-radiating as a perfect black body. Large scale use would alter the Albedo, making the globe warmer.
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Solar collectors are not darker then the darkest black. They are not even marginally darker then asphalt roads and we have millions of miles of them. Solar collectors won't be a problem.

"The authors explicitly disagree with the conclusions of the IPCC, which forsees little or no contribution to 21st century sea-level rise from Greenland and Antarctica" This is not true. The IPCC excludes the effects of ice dynamics beyond a constant extrapolation of past changes, because ice dynamics are not sufficiently well understood to make firm quantitative predictions. The point of Hansen et al. is that enough is known to view the historical worst case as a serious possibility.

Marcus:

Dr. Hansen represents a single scientist among thousands of climate researchers. And frankly, because he does use catastrophic rhetoric in his papers his research must withstand closer scrutiny than others. If the IPCC really does represent the consensus view, let them review this paper and further vet Dr. Hansen's conclusions. Is that okay?

I'm not a scientist, but I am not an unintelligent person. If you don't talk down to me and respond honestly and without condescension to my questions I am more likely to listen to you. In convincing skeptics, this is very important--so don't just spit in their faces. I stayed a skeptic for months because of just this problem.

Satellite measured sea ice extend in South Hemisphere does not show shrinking for period 1979-2007:

http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/current.anom.south.jpg

Good summary on the subject of ice melting with graphs and numbers is here:

http://www.warwickhughes.com/cool/cool13.htm

The picture is far from catastrophic.

There are about dozen articles of Hansen as lead author assessing COOLING effect of antropogenic particles on climate. Official version of IPCC and Hansen is that increased emissions of particles and sulfur components (aerosols) after 1950 lead to cooling of the global climate during 1950-1970s. Influence of particles on sea ice and polar glaciers is non-detectable, and for very simple reason: solar insolation in these regions is very small (half year no sunlight at all), and main factor of sea ice melting is warmer water entering polar regions, warmer wind being the second. The only well-documented warming effect of particles is on snow cover: because of this snow cover in Europe melts couple of days earlier in spring then it did in 19 century.

There are dozens of articles assessing possibility of catastrophic (as” fast” as in 5 centuries) melting of Greenland and Antarctic ice. All of them indicate that due to unique conditions of landscape (bowl in Greenland, ocean shelf in Antarctica) catastrophic disintegration of ice in Greenland and Antarctica is not possible. The worst case scenario is slow – in order of thousand years – melting, if climate will continue to warm, even in run-away mode.

Current article is pure propagandist speculation, and nobody really consider Hansen as scientist anymore, just fraudulent politician.

e.g. Contradiction for contradiction's sake:

"Global warming in the twenty first century: an alternative scenario[7] in which he presents a more optimistic way of dealing with global warming focusing on non-CO2 gases and black carbon in the short run, giving more time to make reductions in fossil fuel emissions. He notes that warming observed to date is largely due to non-CO2 gases. This is because CO2 warming is offset by climate-cooling aerosols emitted with fossil fuel burning and because non-CO2 gases, taken together, are responsible for roughly 50% of greenhouse gas warming." from the Wikipedia bio

[7]"Global Warming in the Twenty-First Century: an alternative scenario" by Dr. James E. Hanson 2000. Proc. Natl. Acad. Sci. 97: 9875-9880.

The problem is that the IPCC process takes six years, and the cutoff for consideration for the latest one was 2005. Hansen has repeatedly called for the National Academies of Science to specifically examine the possibility of the dynamic breakup of Greenland or West Antarctica. The gravity measuring GRACE satellite has shown conclusively that both are losing ice at a rate that wasn't previously considered plausible.

Sea level rise is a matter of history. Hansen's "speculation" is based on paleo climate. As surely as the ice melted in the past during periods of unusual warmth, so will it melt again.

This latest paper restates the "alternative scenario." It does not contradict it. (and contrary to the Wiki article, aerosols offset all warming, be it from CO2, other greenhouse gases, or solar variations)

hampden wireless:
Great point, the amount of black asphalt that we have covered the surface of the earth with is probably much more of an issue than solar panels could be.

I would like to see a study on the amount of heat added due to the black asphalt roofing products, roads, parking lots, etc. versus GHG...I'll bet it's not insignificant.

As CCE points out, the IPCC can be rather conservative. The lower bound for its range of sea level rise (18 cm by 2100) is well less than that based on current rates of rise (0.3cm per year so ~30cm by 2100) observed by satellite altimetry. The IPCC ice models also assumes thermal diffusion when recent observations show surface waters following and growing fissures through the ice sheet.

Let's ignoring future GHG emissions and lag heating due to the current levels and look back at the last time temperatures were as high as today. In the Eemian interglacial (125,000 years ago) sea levels were 4-6m higher than at present. In terms of sea level rise, we are 'dead man walking'. London, Tokyo, New York, Venice, DC, etc. are already under water, they just haven't realised it yet....

Perhaps it's prudent as in all scientific observation to examine more than a single source of data. The GRACE gravitational measurements appear to observe the surface areas beneath the ice sheets rather than the ice itself. Thus, human in-situ observation of polar regions remains a significant, if contradictory source of climate data.

Andrey, can you give references for the influence of Greenland's topology on potential sea level rise?

Regarding aerosols, their role in cooling has not been altered in this paper so I don't understand your point.

As for sedimentation contributing to line stability in Antarctica, this only stabilizes the ice in response to sea level rises. This does not discount rapid melting due to temperatures rises.

Also, any references/quotes on why Hansen is somehow suddenly not considered a serious scientist and instead a politician (by other climate scientists of course)?

Obviously his co-authors did not share your authoritative opinions but I guess they are also just "fraudulent politicians" according to your view?

Talk about shooting the messenger.

Cervus etc it was a "marcus" impersonator who wrote the post before my post addressing Andrey. I hope you can tell the difference.

Marcus:

Perhaps GCC should institute registration for comments. Impersonators are undermining things here and doing their best to provoke flame wars.

- Increasing sea ice extent is not inconsistent with decreasing total ice volume; it can easily be caused by increased rate of outflow.
- Sea level rise does not require the relatively slow process of *melting* polar ice. It would be enough to float ice which is now grounded. Once the ice sheets start to slide off Antarctica and Greenland they can be in the sea in a matter of years. The fossil record shows this has happened before with weaker forcings than are now being applied.
- It's idiotic to imagine that abandoning all of our coastal cities and resettling a billion refugees will be a picnic.
- No sane person is talking about giving up industrial civilization. We just have to start using higher technologies for energy production, such as nuclear, wind, and Solar (ultimately space-based). Burning stuff is for cavemen.

I agree Cervus.

Cervus, I've emailed Mike and passed on your suggestion.

Marcus (the real one):

Greenland “bowl” topography:

http://membrane.com/sidd/greenland.html

suggests that central (two miles thick) ice will not slide into ocean. As for net Greenland ice mass, most current researches adjusted it to relatively small ice loss, if any. Net balance of Antarctic ice is slightly positive, which is not surprising considering slight cooling trend of Antarctic region (and stable temperature of South Hemisphere) as measured by satellites over last 28 years. Satellite measurements are the only reliable means to measure temperature over these regions. Ice does flow from central regions of Greenland and Antarctica to the ocean, but this is what ice does, this is the mechanism which limits ice grows up to the stratosphere. Most of melted ice in central regions solidifies as fast as it is melting, and huge snowfall, especially at winter, covers deposited particles with fresh white stuff. Do not forget that even hottest temperatures in Greenland and Antarctica are 20-40 degrees below freezing, and there is no sun for half year.

Influence on climate and even quantity of emitted aerosols and particles is very poor researched and understood. That’s why both Hansen and IPCC use this wild card to their convenience. From 1950 increased emissions of aerosols and particles from Western countries was used to explain climate cooling until 1970-s, yet it did not affected polar ice, then without quantification of increased emissions of third world it was asserted that the trend seized. Now Hansen suggests that huge quantities emitted from China is enough to melt ice caps, but not enough to cool the climate, since warming continues at increasing rate (it is actually not: adjusted for 1998 huge El Nino event, satellite measured global temperature is stable for about 10 years).

I’ve read dozens of recent articles of Hansen, and they are extremely contradicting. The only thing in common in this conveyer belt is name of Hansen in front and dooms day predictions, passionate cries to do something, and trashing of opponents. It is not science, it is politics, and dirty one.

Andrey,

Although the overall shape of Greenland from that topological map indicates a bowl, there are numerous "holes" through the side so it is not obvious to me how limiting this topology is. Again, I would request you reference a scientific paper backing your claim that this will prevent rapid ice loss. Rarely are things as simple as you imply.

Regarding net mass loss and sea level rise I quote from this recent review (Science 16 March 2007: Vol. 315. no. 5818, pp. 1529 - 1532).

"It is reasonable to conclude that, today, the EAIS is gaining some 25 Gt year–1, the WAIS is losing about 50 Gt year–1, and the GIS is losing about 100 Gt year–1. These trends provide a sea-level contribution of about 0.35 mm year–1, a modest component of the present rate of sea-level rise of 3.0 mm year–1. Because 50 Gt year–1 is a very recent contribution, the ice sheets made little contribution to 20th-century sea-level rise. However, what has also emerged is that the losses are dominated by ice dynamics. Whereas past assessments (47) considered the balance between accumulation and ablation, the satellite observations reveal that glacier accelerations of 20 to 100% have occurred over the past decade. The key question today is whether these accelerations may be sustained, or even increase, in the future."

So although net mass changes are relatively small, the dynamics are changing rapidly. The key issue is that temperature rises are predicted to lead to these dynamical changes. Temperatures are clearly increasing in Greenland and in Antarctica the situation is not clear although I have referenced you previously the most recent paper suggesting a small temperature increase. At some point, if temperatures keep rising, it is obvious that increased precipitation will be out-run by ice loss.

Regarding aerosols, ice core data shows decreased aerosols during warming, presumably due to increased atmospheric moisture and precipitation. Consistent with this is the observation that despite likely recent increased particle emissions as you point out, particle concentrations in the atmosphere have decreased over the last two decades. Hence Hansen describes aerosoles as a rapid feedback factor during climate change. Their net effect is COOLING as is pointed out in Fig. 9.

So, there is nothing inconsistent in the way Hansen describes the effects of aerosols. You seem to think Hansen is suggesting aerosols contribute to the "alebedo flip" mechanism. This suggests either you misunderstand or haven't read the paper.

It is possible that particles and aerosols were having different effects several decades ago.

w/o arguing one way or the other, I want to point out that particles and aerosols have not remained the same.

It could well be that forty years ago particles were generally finer and stayed in the atmosphere longer. And the mix of coal grades being burnt was different.

The emission of particles from the US, Japan, and Europe met wind patterns different than emissions from China and Korea and Russia and SE Asia do today.

The biggest particles I know of are fly-ash from coal. The developed nations made vigorous efforts to suppress it after WW2. I doubt if China, India, and Russia are doing much even today.

Aerosols have changed also. The industry of the world makes different chemicals today and makes the same ones by different methods.

I think the best knowledge for the effect of particles falling on ice is simply what has been empirically measured. And for aerosols the knowledge was certainly not perfect years ago or now.

As I said earlier, Hansen is predicting AGW is worsening quickly. He is getting pretty far from the crowd. That doesn't make him wrong or right.

I don't believe the sky is falling, and that we are doomed. I do, however, think a reasonable approach to clean up the atmosphere would be the prudent thing to do.
As for the Kyoto Treaty, unless the emerging industrialized nations, such as China and India, are part of the mix, the Kyoto Treaty doesn't make a lot of sense.
I am, however, hedging my bets and advertizing my desert property in Arizona as a future seaside resort.

"since warming continues at increasing rate (it is actually not: adjusted for 1998 huge El Nino event, satellite measured global temperature is stable for about 10 years)."

These animations of temperature change clearly show the increasing temperature trend since 1998.

http://data.giss.nasa.gov/gistemp/animations/

What's also clear is that changes are occuring over most of the globe. El nino is a local event.

Andrey?

Marcus.

So called “global temperature” is, in fact, global average of lower troposphere temperature of the air. Air is quite small part of global energy balance; oceans hold 1000 times more heat energy than atmosphere. To put it simple, air temperature is straightforward derivative of two parameters: surface temperature of oceans and major volcanic events. When major volcanic event happens, global temperature goes down big time for 2-3 years. For everything else there is Master Card – ocean temperature. Now, ocean surface temperature oscillates quite substantially (exchange of different temperature layers), take a look at ENSO and especially PDO at Wiki.

El Nino is local event, but of such magnitude that 1998 El Nino raised global temperature for whopping 0.6 C for about a year.

As for global temperature for last 10 years – come on, get real, I believe you can do it. It is stable.

Take a look at satellite measurements (graphed by standard software from official NASA data) at beloved junkscience.com:

http://www.junkscience.com/MSU_Temps/MSUvsRSS.html

Note how “local” El Nino affected global temperatures in 1998.

Andrey, is this troposphere data corrected for the artifacts described by these papers below? I suspect not since according to these papers troposphere temperature trends, once the data is corrected, are consistent with surface temperature trends. Troposphere and surface temperatures are differentially sensitive to various influences including El Nino.

The Effect of Diurnal Correction on Satellite-Derived Lower Tropospheric Temperature. C. A. Mears and F. J. Wentz (2005). Science 309, 1548-1551

Radiosonde Daytime Biases and Late-20th Century Warming
Steven Sherwood 1*, John Lanzante 2, Cathryn Meyer 1

Amplification of Surface Temperature Trends and Variability in the Tropical Atmosphere. B. D. Santer et al. (2005)
Science 309, 1551-1556

For an up to date comparison of surface to satellite troposphere temperatures that incorporates the corrections prescribed by Mears et al., see here:

http://en.wikipedia.org/wiki/Image:Satellite_Temperatures.png

So a warming trend since 1998 is readily apparent.

Andrey?

Come on, get real, I believe you can do it. It is rising!!

ps, Andrey isn't junkscience.com published by Stephen Milloy - famous for receiving money from ExxonMobil while attacking research on global warming as a supposedly independent journalist? Milloy also received almost $100,000 a year from Philip Morris while he ridiculed the evidence regarding the hazards of second-hand smoke as "junk science".

Why is such a site "beloved" by you Andrey?

Who let the denialists out of their straitjackets?