Geoengineering: 'computer-based virtual worlds' tell us how much sunblock Earth needs

From the Pacific Northwest National Laboratory:

Earth sunblock only needed if planet warms easily

Planet’s sensitivity to greenhouse gases will determine how much shading could be needed to slow temperature rise

Ship Tracks South of Alaska

Ship exhaust creates long streaks of clouds across the ocean’s dark surface, making the sky brighter and reducing the amount of heat trapped in the atmosphere. Some researchers are exploring ways to make clouds brighter to reflect more sunlight back into space. Photo courtesy of NASA.

RICHLAND, Wash. – An increasing number of scientists are studying ways to temporarily reduce the amount of sunlight reaching the earth to potentially stave off some of the worst effects of climate change. Because these sunlight reduction methods would only temporarily reduce temperatures, do nothing for the health of the oceans and affect different regions unevenly, researchers do not see it as a permanent fix. Most theoretical studies have examined this strategy by itself, in the absence of looking at simultaneous attempts to reduce emissions.

Now, a new computer analysis of future climate change that considers emissions reductions together with sunlight reduction shows that such drastic steps to cool the earth would only be necessary if the planet heats up easily with added greenhouse gases. The analysis, reported in the journal Climatic Change, might help future policymakers plan for a changing climate.

The study by researchers at the Department of Energy‘s Pacific Northwest National Laboratory explored sunlight reduction methods, or solar radiation management, in a computer model that followed emissions’ effect on climate. The analysis shows there is a fundamental connection between the need for emissions reductions and the potential need for some sort of solar dimming.

“It’s a what-if scenario analysis,” said Steven Smith with the Joint Global Change Research Institute in College Park, Md,, a joint venture between PNNL and the University of Maryland. “The conditions under which policymakers might want to manage the amount of sun reaching earth depends on how sensitive the climate is to atmospheric greenhouse gases, and we just don’t know that yet.”

The analysis started with computer-based virtual worlds, or scenarios, that describe different potential pathways to reduce greenhouse gas emissions, which limits the amount of heat in the earth system due to greenhouse gas accumulation. The researchers combined these scenarios with solar radiation management, a type of geoengineering method that might include shading the earth from the sun’s heat by either brightening clouds, mimicking the atmospheric cooling from volcanic eruptions or putting mirrors in space.

“Solar radiation management doesn’t eliminate the need to reduce emissions. We do not want to dim sunlight over the long term — that doesn’t address the root cause of the problem and might also have negative regional effects. This study shows that the same conditions that would call for solar radiation management also require substantial emission reductions in order to meet the climate goals set by the world community,” said Smith.

How much sun blocking might be needed depends on an uncertain factor called climate sensitivity. Much like beachgoers in the summer, the earth might be very sensitive to carbon dioxide, like someone who burns easily and constantly slathers on the sunscreen, or not, like someone who can get away with SPF 5 or 10.

Scientists measure climate sensitivity by how many degrees the atmosphere warms up if the concentration of carbon dioxide doubles. Smith said if the climate has a medium sensitivity of about 3 degrees Celsius (5.4 degrees Fahrenheit) per doubling of carbon dioxide, “it’s less likely we’d need solar radiation management at all. We’d have time to stabilize the climate if we get going on reducing emissions. But if it’s highly sensitive, say 4.5 degrees Celsius (8.1 degrees Fahrenheit) per doubling, we’re going to need to use solar radiation management if we want to limit temperature changes.”

According to NOAA’s August report, the earth’s temperature has already risen about 0.62 degrees Celsius (1.12 degrees Fahrenheit) since the beginning of the 20th century as the carbon dioxide in the atmosphere has grown from 290 parts per million to 379 parts per million.

But the atmosphere hasn’t reached equilibrium yet — even if humans stopped putting more carbon dioxide into the air, the climate would still continue to change for a while longer. Scientists do not know what temperature the earth will reach at equilibrium, because they don’t know how sensitive the planet is to greenhouse gases.

Further, the study showed that, when coupled with emission reductions, the amount of solar radiation management needed could be far less than the amount generally considered by researchers so far.

“Much of the current research has examined solar radiation management that is used as the sole means of offsetting a doubling of carbon dioxide concentrations. What we showed is that when coupled with emissions reductions, only a fraction of that amount of ‘solar dimming’ will be needed. This means that potential adverse impacts would be that much lower,” said Smith. “This is all still in the research phase. We do not know enough about the impacts of potential solar radiation management technologies to use them at this time.”

The study will also help decision-makers evaluate solar reduction technologies side-by-side, if it comes to that. Smith and his coauthor, PNNL atmospheric scientist and Laboratory Fellow Phil Rasch, devised a metric to quantify how much solar radiation management will be needed to keep warming under a particular temperature change threshold. Called degree-years, this metric can be used to evaluate the need for potential sunlight dimming technologies.

Whether such technologies will be needed at all, time will tell.

This work was supported by the non-profit Fund for Innovative Climate and Energy Research.

Reference: Steven J. Smith and Philip J. Rasch, 2012. The Long-Term Policy 1 Context for Solar Radiation Management, Climatic Change, doi: 10.1007/s10584-012-0577-3. (


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More from the loony left? More models.

What could possibly go wrong?


Not much to say, other than I’m just totally lost of words….
It just feels as though the Warmists are putting science back to the pre-enlightenment era. Are western economies so wealthy that they can afford to waste huge sums of money on this junk ? I wonder how the earth could possibly have existed for 4.5 billion years without these wondrous new technologies they’re attempting to develop.
Clearly the world’s gone mad !

Tony B (another one)

I think that should be “supported by the Fund for Useless Climate and Energy Research”. And that makes a nice, appropriate acronym, too.
Truly, they are scraping the bottom of the barrel


Weather watch: Southen and Eastern Australia experiencing extremely cold spring weather, with snow in areas that are almost unprecedented for October. No mention of global warming in the news, which is probably the biggest news of all.


” to potentially stave off some of the worst effects of climate change…”
Which “worst effects” are we talking about? Haven’t seen them yet…..


Bloody lunatics, god help us if this is ever allowed!

Nick Luke

I hope some really clever lawyer is sharpening his pencil to sue on behalf of those of us who need as much sunshine as we can get for our businesses and life style.
There are millions who rely on sunshine to ripen crops and provide food. We have in front of us this year, in the UK, proof that too much rain destroys crops and pushes up prices, so too does too little sunshine. Who’s to say exactly how much shade will produce just the right amount of cooling without some unintended, and unforeseen until after the event,consequence running out of control. Leave well alone.

As usual they only consider half the story. When I was involved in anti-submarine work in the North Atlantic we had to keep track of all surface vessels, especially what were called ELINT trawlers. It’s an abbreviation of Electronic Intelligence Trawlers, which were Soviet “fishing vessels” festooned with antenna and electronic monitoring devices that sat of the coast all the time in international waters. They were also temporary supply vessels in the event of conflict as we witnessed during the Cuban crisis. Massive factory ships that processed the catch at sea served the same purpose.
In order to track these and other vessels we would frequently patrol in passive mode. This meant flying without any detecting equipment like radar operating at all. The east coast of Canada is the foggiest area in the world so lack of radar was a problem. We soon realized that the heat from the trawler or other vessel burned off the fog for a considerable distance behind the vessel, certainly as far as the condensation trails in the photo shown above. It taught me much about the delicate balance between temperature, condensation and evaporation that I applied when I went back to university to study climate change.
In addition, there are the lower levels of fog created by the urban heat island effect. But that is not the end of the list.


Ha ha. That’s funny because they say the sun is bad for us and it causes skin cancer so we need sunblock lotion to prevent skin cancer…
Only to find out that we have a widespread vitamin D deficiency and we need the sun for vitamin D. NO FOOD can match the amount of vitamin D we get from the sun. Not only that, vitamin D at the right dosage or optimal level can significantly cut down risk of getting all kinds of cancers.
Here is the link to show that we need vitamin D for so many things –
So… maybe the earth needs sun for something we don’t know about yet? Will trying to reduce solar radiation cause more problems like it did for us with sunblock lotion?


“The analysis, reported in the journal Climatic Change, might help future policymakers plan for a changing climate.”
I wasn’t really worried until the term “policymakers” reared its ugly head.
The electorate ultimately makes policy, with its votes.
Never forget that.

Dr Strangelove?


‘drastic steps to cool the earth would only be necessary if the planet heats up easily with added greenhouse gases
Sort of sounds like an attempt to back out of ‘man-made’ global warming. Anyone else get that sense?

Dennis Gaskill

Do you suppose, that by playing, with this stuff, the AGW guys will figure out that it might be a good idea to include clouds or water vapor in their Modeling?
All of their research begins with the assumption that CO2 causes catastrophic GW.
If we get a new president ….we should cut off the money for all such research!

Dr. Bob

I discussed this with a Harvard professor years ago when he thought we needed to mitigate AGW with stratospheric sulfate particles. What struck me then as now is this is most likely one experiment that cannot be taken back if it goes wrong. And Murphy says it will go wrong. Mostly because you are trying to do something for all the wrong reasons and don’t really understand the potential outcomes.
One hopes this is just a total waste of money and idle speculation. As the alternative is truly scary.

I’m not at all concerned at the prospect of CO2 increases. I’m very apprehensive at the thought of geo-engineering. Given humankind’s track record of cock-ups when trying to improve on nature, I can’t see any good outcomes from this kind of exercise.

Russ R.

If I read this correctly, climate scientists finally admitted 1) that they don’t know what the right value for climate sensitivity is, and 2) that increased cloud cover is a negative feedback.


When “researchers” start messing with the atmosphere, billions will die.


Mankind screwing with nature… what could possibly go wrong /sarc

Sweet Jesus, that’s about 10 inches away from C***t***l material.

Steve C

‘Computer-based virtual worlds’ tell us how much sunblock Earth needs? Sorry, Pacific Northwest, but ‘computer-based virtual worlds’ can only ever tell us how much sunblock ‘computer-based virtual worlds’ “need”. And as our home planet appears to be sliding into another Little Ice Age, it should dawn soon enough, even on you, that the amount of sunblock we “need” is a negative amount.


There’s gonna be one heck of a lawsuit because of all this. I’m reminded of that movie where the Army accidentally stopped the rotation of the earth’s core causing birds to fly upside down.


yet again, I am aghast at the stupidity!
and BTW, just for completeness – they do KNOW, do they not, that sunlight is used by PLANTS to take CO2 out of the atmosphere? Did they add that into their silly models?

Robert C

“The conditions under which policymakers might want to manage the amount of sun reaching earth depends on how sensitive the climate is to atmospheric greenhouse gases, and we just don’t know that yet.”
At least they got one thing right.

What is it with some of these groups and their unhealthy fascination with blocking out the sun?
Don’t they know that the opposite of sun light and warmth is darkness and cold?

I don’t think that’s ship exhaust.


I think they have watched the Original Total Recall one too many times….


Sinclair, K.E., Bertler, N.A.N. and van Ommen, T.D. 2012. Twentieth-century surface temperature trends in the Western Ross Sea, Antarctica: Evidence from a high-resolution ice core. Journal of Climate 25: 3629-3636.
“no significant trends between 1882 and 2006.”
If the state sponsored religion of CAGW believes that the “scientific” endeavours of geoengineers are required it will be so. At the risk of using a religious metaphor, such models are truly Babylonian in their conceit and arrogance, the potential consequences of such meddling unpleasant to contemplate.

Such idiotic thinking never ceases to amaze me. To correct what they deem as mankind meddling with the balance of the climate, they are proposing to meddle with the balance of climate. The problem is this is not the first time these “enlightened” grant seekers have proposed messing with the climate to reverse the effects of man messing with the climate. I think, however, that these people really only want to be rich and so the easy way to do that is to put out a scientific paper that blames mankind for some ill, real or pretend.

F. Ross

“… We do not want to dim sunlight over the long term — that doesn’t address the root cause of the problem and might also have negative regional effects. …”

What problem? [sarc]

“Scientists measure climate sensitivity by how many degrees the atmosphere warms up if the concentration of carbon dioxide doubles. …”

They really actually measure that, do they? [sarc]
They don’t know the “normal” temperature of the atmosphere. They use badly sited instruments to get bad information on daily temps, then re-adjust the historical records to show whatever they want it to show. Cloud feedbacks/or forcings [whichever flavor is currently pushed] are virtually wags.


Hi all I’m a long time viewer first time poster here.
I thought this vid might clear the contrail V chemtrail debate up It’s hard to take any scientific info into account regarding climate change if weather modification isn’t being taken as an IS Are scientists notified were and when these are taking place Australia is spending 10 million for their 2012 weather modification program. The 2012 weather modification meeting time table .


“Scientists do not know what temperature the earth will reach at equilibrium, because they don’t know how sensitive the planet is to greenhouse gases.”
This about says it all. The estimates of sensitivity promoted by the AGW alarmists are clearly too high, but no one knows how much too high.
Once Kirkby et al establish how sensitive the globe’s temperature is to changes in cosmic rays, the value for the supposed CO2 feedbacks will be further constrained. For CO2 alone, of course, the calculable Planck response is 1.23 degrees per doubling. Only the H2O feedbacks are unknown.

Mickey Reno

These people are going insane. On the upside, NOAA is putting itself in the running for another block of money Romney can cut from government spending if he gets elected.

Nolo Contendere

Apparently there’s no end to what the Steaming Load Model can come up with!

Perhaps the strangest claim was that a geoengineering solution can only be a “temporary fix.”
Apparently they are looking for GHG reduction to stop the warming. But what if that (as is likely)
fails? If the system works and is needed, why stop using it? Makes no sense. As for differential effects, why can’t the system only shield places where it doesn’t affect anything or anybody, like over the oceans?

William McClenney

Always. Every single time. Absolutely not a single thought as to when we live, at the possible end of a half-precessional old extreme interglacial. What could possibly go wrong here? We could tip ourselves into the next glacial with geoengineering. What does the vaunted Precautionary Principle say about that? Hmmmm?

In 1980, 7 Pinaubo’s worth of SO2 was released into the atmosphere by man. By 2000, it was down to 6 Pinatubo’s.

“since the beginning of the 20th century as the carbon dioxide in the atmosphere has grown from 290 parts per million to 379 parts per million.”
This is, of course, ignoring the actual Co2 during the 1940s at 440-550 ppm, blowing the false, fabricated, constant 290 ppm of the IPCC hand puppets out of the water. But, can’t let facts get in the way of your agenda, can we?

Leo G

It might be safer and easier to cool the surface of the planet by allowing sea levels to rise and allowing some marginal increase in the proportion of the planet covered by oceans.

Carbon taxes and controls have always been the objective for the government funded warmist [big warm] position. Geoengineering has always bee the fall back objective for the government funded luke [little warm] postion. All of the supposed “sunscreens” have some level of toxic effect and the major GMO patent holders have developed the only geoengineering resistant strains of food crops. This is all the work of monarch-monopolists who currently control western corporations, faux democracies and rote education. There is NO Carbon warming, big or little, and no need for toxic spraying….or the ludicrious space mirror protection racket.


elmer says:
October 11, 2012 at 3:48 pm
I don’t think that’s ship exhaust.
It probably is, but caught with perfect lighting in ideal atmospheric conditions.
It probably only sets up like that…a couple times a year ?
Sure is striking though !!
Engineering geniuses, ensuring adequate supplies for the masses.

Bill Illis

Sulphates destroy Ozone and the location they most often propose to dump the sulphates in – you guessed it, smack dab in the middle of the Ozone layer.
They are just insane obsessed scientists. There is no other description that fits.
All those movies of the future where humans have wrecked the planet are really based on these type of scientists having their way.
Now technically, all these experiments are banned under the International Convention on Biodiversity that almost all countries have signed but noone seems to know that (especially these obsessed climate-fixing scientists).
And my backyard and your backyard is experiencing exactly the same temperature that it has for the last 100 years. The climate has not changed no matter how much the NCDC/GISS/Hadcru says it has. We need to get the guys who run these institutions removed from their positions and have objective people put in charge instead before it does lead to someone destroying the Ozone layer.

Ray Bratton

I suspect these are aircraft vapor trails, not ships. Or perhaps just a very busy shipping lane on a windless day! Can someone more knowledgeable than me check?

Duncan says: Bloody lunatics, god help us if this is ever allowed!
EVER ALLOWED? how do you account then for Chemtrails etc?

I could list dozens of ways humans have changed the Earth’s albedo, both on the surface and in the atmosphere. And I happen to think these albedo changes are the primary cause of what climate warming there has been.
If we were serious about cooling the Earth’s climate, it’s in fact relatively easy to do. City planners and engineers are now incorporating high albedo materials into buildings, to both cool the buildings and cool the cities. The cooling results from reflecting the sun’s energy straight back out to space. Hence it also cools the climate.
You could argue that this won’t make enough of a difference, but its something that’s easy to ramp up and down, and has none of the risks of atmospheric experiments. If sudden cooling occurs, we can just cover those high albedo surfaces with black paint.
On a side note, where I live most people have very high albedo reflective roofs to help keep their houses cool, and as I mentioned with the incidental benefit of cooling the climate, now with the solar energy craze they are covering those high albedo roofs with very low albedo solar panels, which will both warm the urban areas and the climate. That no one ever mentions this, helps persuade me, all of this cooling the climate talk isn’t serious.


How about a little ice-nine?


Ray Bratton says:
October 11, 2012 at 6:09 pm
I suspect these are aircraft vapor trails, not ships. Or perhaps just a very busy shipping lane on a windless day! Can someone more knowledgeable than me check?
I would go with the latter, no need to check.
The heat from the ships exhaust plume, causes the surrounding air to rise into the colder air, where it condenses to form clouds.
I don’t imagine these are seen in the tropics ?

G. Karst

If geoengineering is to be considered then the emergency must be great indeed. I cannot see such an emergency with benign CO2 or a beneficial warming. I can easily see such an emergency arising should we begin prolonged temperate zone cooling. Warming has enabled an expanded human population and sustained long term cooling would present such dire emergency IMHO. Cooling is always dangerous… warming is a pleasant walk in the park.
It is important that the climate fundamentals be clearly determined as no mitigation, of cooling, can be attempted until a highly skilled modality is constructed. How can that ever happen, while our skills, funding, talent is busy chasing it own CO2 A$$. Identifying the exact cause and mechanism of rapid glaciation must be fully determined.
Unless one believes we can bioengineer plants to thrive on frozen ground lol. GK

old engineer

These paragraphs were under the NASA video that showed the ship cloud tracks:
“However, no camera captured that image of the Earth. The reason? It’s not one image. Instead, the single cloud-scattered globe is a mosaic of 298 smaller images of close-up areas of our planet meticulously stitched together by Helen-Nicole Kostis, a NASA science visualizer.
At NASA Goddard Space Flight Center’s Scientific Visualization Studio (SVS), Kostis works as part of a team of visualizers who take raw scientific data and translate that data into visual imagery. The visuals help both scientists and the general public better understand the data NASA satellites and airborne missions provide in order to better comprehend complex phenomena invisible to the naked eye and “see” how the planet works. The imagery they create is scientifically accurate to a degree few others match.
Many Earth views we see in print and video are created by artistically splicing together various images from different satellite instruments, taken at different times and heights, in different wavelengths of light, and at different pixel resolutions. Using image-blending techniques, photo artists create a realistic-looking two-dimensional flat view from these disparate images. They then wrap this image layer, called a “texture,” onto a sphere in a software program to create a view of Earth. While it makes for stunning imagery, the Earth depicted in these views is fictional — a hodge-podge of different images created from a great deal of artistic license.”
So. it is not clear that these are actual visual clouds at any one moment. If a ships hot exhaust could create clouds like this, why don’t our freeways show up as cloud streaks on satellite photos?
We may be seeing something “created from a great deal of artistic license.”

David Schofield

When I read the summary why was I reminded of the Mayan priests in the film ‘Apocalypto’?