Geoengineering

[knocker]

Climate Engineering: minor potential, major side effects

 

25 February 2014/Kiel. With global greenhouse gas emissions continuing to increase proposals to limit the effects of climate change through the large-scale manipulation of the Earth system are increasingly being discussed. Researchers at the GEOMAR Helmholtz Centre for Ocean Research Kiel have now studied with computer simulations the long-term global consequences of several “climate engineering†methods. They show that all the proposed methods would either be unable to significantly reduce global warming if CO2 emissions remain high, or they could not be stopped without causing dangerous climate disruption. The study is published in the international journal “Nature Communicationsâ€.

 

http://www.geomar.de/index.php?id=4&no_cache=1&tx_ttnews[tt_news]=1754&tx_ttnews[backPid]=185&L=1

[BornFromTheVoid]

Somewhat relevant to this thread...

 

Taming hurricanes with arrays of offshore wind turbines

 

Hurricanes are causing increasing damage to many coastal regions worldwide¹, ². Offshore wind turbines can provide substantial clean electricity year-round, but can they also mitigate hurricane damage while avoiding damage to themselves? This study uses an advanced climate–weather computer model that correctly treats the energy extraction of wind turbines³, ⁴ to examine this question. It finds that large turbine arrays (300+ GW installed capacity) may diminish peak near-surface hurricane wind speeds by 25–41 m s−1 (56–92 mph) and storm surge by 6–79%. Benefits occur whether turbine arrays are placed immediately upstream of a city or along an expanse of coastline. The reduction in wind speed due to large arrays increases the probability of survival of even present turbine designs. The net cost of turbine arrays (capital plus operation cost less cost reduction from electricity generation and from health, climate, and hurricane damage avoidance) is estimated to be less than today’s fossil fuel electricity generation net cost in these regions and less than the net cost of sea walls used solely to avoid storm surge damage.

 

http://www.nature.com/nclimate/journal/v4/n3/full/nclimate2120.html

 

Review of the article

http://theconversation.com/wind-turbines-could-put-the-brakes-on-hurricanes-23705?utm_medium=email&utm_campaign=Latest+from+The+Conversation+for+27+February+2014&utm_content=Latest+from+The+Conversation+for+27+February+2014+CID_c408a42058dd9079144a098707f56a2a&utm_source=campaign_monitor&utm_term=Wind%20turbines%20could%20put%20the%20brakes%20on%20hurricanes

[Snowyowl9]

Geoengineering side effects could be potentially disastrous, research shows.

http://www.theguardian.com/environment/2014/feb/25/geoengineering-side-effects-potentially-disastrous-scientists?CMP=twt_gu

[be cause]

Is this geo-engineering at work ? 

 

a fly-by seeding of Hurricane Amanda at the weekend as revealed by satellite ???

[Polar Maritime]

Well at least Iliterate cannot blame this any more..

 

Air Force prepares to dismantle HAARP ahead of summer shutdown.

 

Responding to questions from Sen. Lisa Murkowski during a Senate hearing Wednesday, David Walker, deputy assistant secretary of the Air Force for science, technology and engineering, said this is "not an area that we have any need for in the future" and it would not be a good use of Air Force research funds to keep HAARP going. "We're moving on to other ways of managing the ionosphere, which the HAARP was really designed to do," he said. "To inject energy into the ionosphere to be able to actually control it. But that work has been completed."

Comments of that sort have given rise to endless conspiracy theories, portraying HAARP as a superweapon capable of mind control or weather control, with enough juice to trigger hurricanes, tornadoes and earthquakes.

Scientists say all of that is nonsense, and that the degree of ionosphere control possible through HAARP is akin to controlling the Pacific Ocean by tossing a rock into it.

http://www.adn.com/2014/05/14/3470442/air-force-prepares-to-dismantle.html

Read more here: http://www.adn.com/2014/05/14/3470442/air-force-prepares-to-dismantle.html#storylink=cpy

 

Read more here: http://www.adn.com/2014/05/14/3470442/air-force-prepares-to-dismantle.html#storylink=cpy

[knocker]

Adjusting Earth’s thermostat, with caution

Harvard scientists say aspects of solar geoengineering can—and should—be tested without need for full-scale deployment

 

http://www.seas.harvard.edu/news/2014/11/adjusting-earth-s-thermostat-with-caution

[Nights King]

Never been a fan of geoengineering..... we don't seem to to have a handle on the scale of impacts our tinkering is having already so why wouldn't messing even more not just add into the mess? 

 

We are all doomed anyway though with our run away global warming, what harm could a little tinkering do? I am sure if the same scientists and models that can "accurately" forecast the warming over the past 30 years then we should trust them to adjust and model the effects of a man made adjustment to earths thermostat?

 

I actually think it would be quite interesting to see geo engineering tested.

[Gray-Wolf]

I'm not best pleased with the geoengineering we're already on with? There is such a wide range ( or so we are lead to believe?) of possible impacts from what is already ongoing that to further tilt the equation does fill me with dread!

 

As you probably know I worry that we have a few problems approaching involving climate 'snaps' where the system jumps to the next 'stable' point and how this impacts climate, and our ability to feed ourselves , truly worries me. I cannot see the sense in further pressing the climate until we better understand just how quickly things respond with the loading we already have?

[Nights King]

I'm not best pleased with the geoengineering we're already on with? There is such a wide range ( or so we are lead to believe?) of possible impacts from what is already ongoing that to further tilt the equation does fill me with dread!

 

As you probably know I worry that we have a few problems approaching involving climate 'snaps' where the system jumps to the next 'stable' point and how this impacts climate, and our ability to feed ourselves , truly worries me. I cannot see the sense in further pressing the climate until we better understand just how quickly things respond with the loading we already have?

 

There lies the problem, I'm still not convinced this slight global warming in the last century (man made or not)  is a bad thing really for a start it benefits more regions on earth than it does not?

 

I can't see the Russians or other arctic regions or in fact most countries signing up to cool the planet down with geo engineering (however interesting it is ) to save a few insignificant species of animals over us humans which would do far better on a warmer planet with higher yields.

[Guest]

Problem 1 - to find ways of decreasing the temperature in such ways is going to detract from the main purpose of cutting back on CO2 emissions, so,it is more likely that CO2 will continue to increase - we are now finding that the CO2 is so giving rise to increased acidification of the oceans - this is important inasmuch as the acidification weakens the abilities of crustacions to grow their shells, without which they would be unable to survive and since they are generally the bottom of the food chain othe species will die out through lack of their food. With an increasing global population we should not be taking any risks on such an important source of food as marine life.

Problem 2 - we have no proper idea as how this will affect global weather systems - my guess is it could be similar to the year 1816 which was described as a year without a summer and this was caused by volcanic activity. In our history there have been other eruptions causing particulates in the atmosphere, resulting in poor harvests and starvation.

In my view we would be far better off by developing solar powered desalination plants to irrigate desert regions, thereby increasing food production. These areas could also be used for bio- fuels and give an opportunity to stop the deforestation we are currently experiencing in the tropics.

Edited November 26, 2014 by mike Meehan

[Gray-Wolf]

I'd agree that we would be best served investing in mitigation of the impacts that we are moving toward.

[knocker]

Stratospheric dynamics and midlatitude jets under geoengineering with space mirrors, and sulfate and titania aerosols

 

Abstract

The impact on the dynamics of the stratosphere of three approaches to geoengineering by Solar Radiation Management is investigated using idealized simulations of a global climate model. The approaches are geoengineering with sulfate aerosols, titania aerosols and reduction in total solar irradiance (representing mirrors placed in space). If it were possible to use stratospheric aerosols to counterbalance the surface warming produced by a quadrupling of atmospheric carbon dioxide concentrations, tropical lower stratospheric radiative heating would drive a thermal-wind response which would intensify the stratospheric polar vortices. In the Northern Hemisphere this intensification results in strong dynamical cooling of the polar stratosphere. Northern Hemisphere stratospheric sudden warming events become rare (1 or 2 in 65 years for sulfate and titania respectively). The intensification of the polar vortices results in a poleward shift of the tropospheric midlatitude jets in winter. The aerosol radiative heating enhances the tropical upwelling in the lower stratosphere, influencing the strength of the Brewer-Dobson Circulation. In contrast, solar dimming does not produce heating of the tropical lower stratosphere so there is little intensification of the polar vortex and no enhanced tropical upwelling. The dynamical response to titania aerosol is qualitatively similar to the response to sulfate.

 

http://onlinelibrary.wiley.com/doi/10.1002/2014JD022734/abstract?utm_content=bufferdeeef&utm_medium=social&utm_source=twitter.com&utm_campaign=buffer

[iapennell]

In the 1970s when meteorologists were concerned about global cooling and the threat of a new Ice Age coming there were some who advocated dusting ice-sheets at high latitudes with soot from suitably modified aircraft so that the ice-sheets would absorb much more of the Sun`s heat and melt (and in so doing stopping the spread of ice in it`s tracks).  When the "Grand Solar Minimum"-induced cooling hits in the next 20 years geo-engineers might be discussing this again!  In the meantime it is interesting that scientific community have been giving serious thought as to how to keep the Earth cool in the face of rising CO2 emissions over recent years.

 

My view is that geo-engineering solutions are very costly and even in the early 21st Century stretch mankind`s technological resources; but that as much as possible should be done to prevent a global warming that would bring deadly heat to the tropics and mid-latitude continents in summer along with coastal flooding as sea levels rise (though it is my view that serious warming that is likely to result in intolerable summer heat and mass-melting ice-sheets this is not going to happen until near 2100- after the coming Grand Solar Minimum and if\when CO2 levels are much higher than nowadays). 

 

Governments, instead of spending ££ billions on wind-farms and solar panels that push up fuel bills, should spend money on Research and Development into effective, low-cost methods of preventing dangerous global warming:  Measures such as blasting MASSIVE CANNONS at massive speed into space (by blasting at the Sun at noon in June) from the Arctic in summer which, if repeated every summer, would slowly reduce the tilt of the Earth to 22 degrees by 2100 (not 23,4 degrees as a present); the effect of this would be a sharp reduction in incident Summer Sunshine in the Arctic (and Antarctic six months later) that would ensure the high latitudes stay cool enough to preserve the ice-caps (and preserve our coastlines).  In mid-latitudes reducing the tilt of the Earth in this way would lead to slightly less dark winters (and perhaps slightly less cold winters too with the winter Sun a bit higher above the horizon) but significantly cooler summers; less intense Summer Sun and cooler high latitude regions that would be the source of some even cooler summer air would help prevent deadly summer heatwaves. Another possible measure could be to cover one million square miles of the tropical Pacific with giant floating-mirrors to reflect away the strong tropical Sun`s heat (surely it is not beyond the technological abilities of mankind if resouces are collaborated globally to do something like this?).  If mankind has the technology to create nuclear weapons surely something like this could be devised to arrest dangerous global climate shifts (something that does not involve wrecking the global economy and condemning millins to poverty)??

 

Ian 

Edited January 16, 2015 by iapennell

[Gray-Wolf]

I'd take a look at charcoal fixing of CO2 into long term storage in the soils of the planet. A process available to everyone and a far better 'fix' than planting trees alone!!!

[iapennell]

Here are a few Geoengineering Solutions that might be technologically feasible (we would need internationally agreed cooperation):

 

1) Altering the tilt of the Earth from 23.4 degrees to 22 degrees over the next 100 years by blasting thousands of massive cannon balls directly at the noonday sun in June in the Arctic over coming years.  Either that or thousands of very powerful and very heavy  scud-missile type rockets could be fired from space horizontally into the south-facing side of remote Arctic mountains (again this has to be midday in June local time).  The production of these "missles" or cannons would make more CO2 but perhaps carbon capture could be used in the gas discharges of the factories required to produce them.  Reducing the tilt of the Earth from 23.4 degrees to 22 degrees would reduce solar input to the Arctic and Antarctic by 10 to 15%; not only is the Sun shining at a lower angle but the radiation has to pass through a longer extent of the atmosphere before reaching the surface.  This would help preserve the snow and ice at high latitudes (which in turn would continue to reflect the Sun's heat):  Melting ice-sheets and attendant threat of rising sea-levels averted!

 

By reducing the intensity of the Summer Sun in mid-latitudes and putting the winter Sun just a little bit higher in the sky it would moderate regirous extrmes between summer and winter in mid-latitude continents.  The bigger impact would be cooling in summer and this would help many locations that look set to suffer intolerable summertime heat if the Earth warms more.  On the downside reducing the thermal advantage subtropical continents gain over the equator in summer is liable to weaken monsoon rains in West Africa and southern Asia, but it is possible to help these countries adapt to a drier future by encouraging them to grow drought-resistant crops.

 

2) A cheaper and much more technologically-feasible option incolves building very long floating-plastic "walls" with barriers extending from the surface to a depth of 100 metres, but with "channels" thrugh the walls at 20-mile intervals to let ships through:  These walls would be built from Bodo in Arctic Norway to Akureyri in Iceland and thence to the East Greenland Coast.  Another such floating wall would extend from Godthaab to the islands of the Canadian Arctic and also another such wall would bridge the Bering Strait.  Warm waters from the Gulf Stream would still reach almost all habited parts of Europe, but the plastic wall extending down to 100 metres below the sea would stop warm waters penetrating the Arctic.  The interior arctic would get colder and snow and ice would increase there to offset the effect of rising CO2 levels, colder conditions over the high Arctic would forestall the melting of the Grenland Icecap.

 

With the Arctic "Wall" in place we could then plan to set about building a similar one around Antarctica along 60S; this would need to be sturdy to withstand the winds in the Southern Ocean. It would be built in time to prevent serious melting of any part of the Antarctic ice-sheets.

 

The obvious drawback is the manufacture of enough plastic to build "floating walls" in the ocean extending to 100 metres' depth and for 1000s of miles in length.  Also, plastic does degrade over time, though the toughest synthesized plastic could last fifty-plus years.

Another drawback is that by preventing warm ocean currents reaching the Arctic the temperature-gradients between the Arctic and mid-latitude oceans would intensify (especially in autumn and winter).  This could lead to more intense storms that batter North West Europe, but again that is something we could adapt to; the strong zonal index weather patterns implied by the intense, strong Westerlies would also ensure more or less permanent high-pressure over the Mediterranean and southern USA, which means such locations would be afflicted by devastating drought with large areas turning to desert.  Again, this is not an insurmountable problem as water-desalination plants could be built.

 

3) Huge amounts of salt (billions of tonnes) could be mined and sent up into space about 4,000 miles above the Earth, where it would be released by the rockets carrying them as they started travelling in orbit around the Earth directly above the equator.  A huge amount of fuel (producing CO2) would doubtless be expended in the mining and then the transporation of salt to above the thermosphere to be released in orbit, but if enough salt can be transported up there that the Solar Radiation reaching Earth drops by 1% (because of the Earth's new reflective white salt-ring girdling the equator) this would more than offset the effect of a CO2 doubling. There is fifty-plus years to work on this and the technology/resources needed to achieve this.  Salt already exists in vast quantities in the sea and it can be mined.

 

The side-effects of this sort of operation would be minimal, save for a small drop off in convection-driven rainfall in the tropics (because of the weaker sun), but (again) developing tropical countries can be helped to grow drought-resistant crops.

Edited January 19, 2015 by iapennell

[iapennell]

A variation of putting billions of tonnes of salt into orbit around the Earth could be for man to engineer an explosive volcanic eruption every few years (from a relatively remote area of a tropical volcano, good idea to evacuate any locals there might be!):  This could be done by drilling deep into a volcano crater using an automated drill (just in case it blows up when someone is drilling it), then putting millions of tons of TNT into the volcano and igniting it.  The resultant explosion would send billions of tons of ash and sulphur high into the stratosphere to cut down the Sun's heat at the surface for a few years.  Several such engineered volcanic explosions could have sufficient cooling effect at the Earth's surface to buy much more time (maybe 100 years)  to reduce CO2 emissions or research other (more permanent) solutions to preventing the Earth heating up.

 

This is a relatively cheap solution compared to some of those I have discussed above, but there are drawbacks:  The explosions and man-made volcanos would disrupt local wildlife and local human populations would need re-homing.

[iapennell]

Another possible solution to mitigating global warming could be the painting of all mountains that never get snow but that are sparsely populated brilliant white:  International legislation could be passed to this effect and special white paint (or perhaps refined salt) could be sprayed onto barren mountains each year to keep their albedos above 60%!  

 

Only there is a drawback; how much CO2 would be released in sourcing the materials for (and manufacturing) the paint or refined salt needed to maintain all barren mountains in a white state?  

[BornFromTheVoid]

Another possible solution to mitigating global warming could be the painting of all mountains that never get snow but that are sparsely populated brilliant white:  International legislation could be passed to this effect and special white paint (or perhaps refined salt) could be sprayed onto barren mountains each year to keep their albedos above 60%!  

 

Only there is a drawback; how much CO2 would be released in sourcing the materials for (and manufacturing) the paint or refined salt needed to maintain all barren mountains in a white state?

You also have to consider the environmental and ecological impacts. While they might be sparsely populated by us, they probably have their own ecosystems. Not to mention that it would require constant work due to erosion, dust, rain, etc.

[BornFromTheVoid]

Q&A on /r/science at the moment.

 

Science AMA Series: We authored two recent studies covering options for human intervention to address climate change for the National Academies of Science, Engineering, and Medicine, Ask Us Anything!

Hi reddit,

I’m Scott Doney, a Senior Scientist at the Woods Hole Oceanographic Institution. My research focuses on how the global carbon cycle and ocean ecology respond to natural and human-driven climate change.

I’m Waleed Abdalati, Director of the Cooperative Institute for Research in Environmental Sciences at CU-Boulder’s Geography Department. My research focuses on the use of satellites and aircraft to understand how Earth's ice cover, particularly glaciers and ice sheets, is changing and what those changes mean for life on Earth.

We’re talking about risks and possibilities of climate intervention, or as it is often referred to, geoengineering. Ask us anything!

You can read more about the work the National Academies are doing here.

 

https://www.reddit.com/r/science/comments/3gge6v/science_ama_series_we_authored_two_recent_studies/

[knocker]

Is David Keith’s climate solution genius or madness?

 

David Keith is a leading figure in the world of geo-engineering — manipulating the Earth’s atmosphere to counteract global warming. Some think his ideas are crazy, but he argues we’d be crazy to ignore them.

 

http://www.thestar.com/news/insight/2015/09/27/is-david-keiths-climate-solution-genius-or-madness.html

Edited September 27, 2015 by knocker

[solarcycle]

[iapennell]

On a serious note, do we dismiss all ideas of geo-engineering because there are inherent risks in them?  This climate summit in Paris was full of vague commitments by 148 countries to reduce CO2 emissions and "limit" global temperature rises to 2C by aiming for 1.5C warming above pre-industrial temperatures.  CO2 levels have now reached 400 ppm whereas in the 19th Century CO2 averaged 260 ppm, the climate is still adjusting to equilibrium and a doubling of CO2 from industrial levels (to 540 ppm) plus likely effects from methane being added to the atmosphere causes an initial forcing of 8 Watts per square metre.  From Stefan's Law this is a warming of 1.5C (given the Earth is in balance with Solar input absorbed and radiative heat loss each at about 240 W/m^-2) but add in the feedbacks from increased water-vapour trapping more heat and reduced snow cover (both seasonal and permanent) reflecting less heat from the Sun then the warming for doubled CO2 plus methane from pre-industrial times is 2.5 to 3C (there is some negative feedback due increased atmospheric convection and more global cloud-cover having an overall surface cooling effect). 

Global temperatures are already 1C above pre-industrial times, yet the atmosphere is still adjusting to higher CO2 levels today.  It is however, my contention that the Sun is about to enter a Maunder Minimum phase lasting 30 to 40 years, during which Solar output will drop by 0.5 to 1%.  This forcing will counter the effect of rising CO2 levels for a time and will lead to a slight global cooling lasting about 20 years.  This will buy some time but not a lot of it.  Thereafter however, further rises in CO2 levels combined with rising solar output will cause a sharp spike upwards in global temperatures by circa 2060.  It means that governments across the World as a whole have forty years, at most, to prevent CO2 levels exceeding 500 ppm above which global temperatures will be destined to rise over 2C above pre-industrial levels:  It is above a mean global temperature of 17C that the Greenland Icecap will melt catastrophically, that deadly killer heatwaves will become common in Europe and North America, that sea-levels will start rising rapidly causing the loss of big cities like London and New York to the sea, that severe drought and savage summer heat will make Mediterranean lands unsuitable for either agriculture, tourism or human habitation.  Yet the measures required by governments around the World to cut emissions to prevent this happening (80% reductions in CO2 levels) mean such severe restrictions on using coal, oil and gas (and such taxes put on such pollution) that it would condemn billions of folk to poverty and cause a global recession.  This is neither an electorally practical or realistic option.  So we have to look at other measures of actively preventing global rises in temperature using man's technological means.

None of the measures listed below are without risk but they are all relatively cheap and practical, and if any cause human death or species loss they are as nothing as to what would happen if we allow Global Warming to get out of hand:  These measures include.

1) Exploding a couple of powerful H-bombs on a remote tropical island in the middle of the Pacific (after evacuating it).  The massive ash cloud and dust raised would reach the mid-stratosphere and cut the solar energy reaching the surface globally by 2% for a few years (the Nuclear Winter is a much more serious extent of this happening).  This would buy time, possibly a decade or more for humankind to develop a proper low/zero carbon economy on a global scale.  The drawback is of course the radiation fallout but this significant fallout would be thousands of miles from any big population centres  and it would only affect species on the island concerned.  Don't forget the Russians tested their H-bombs in the Pacific in the 1950s and 1960s without discernible impacts anywhere else in the World.

2) Firing tens of thousands of very powerful rockets into space towards the midday Sun in June from an Arctic mountain.  The combined recoil force would nudge the Earth's tilt towards 23 degrees then 22.5 degrees (i.e to make it less) over a hundred years.  The effect would be to reduce the strength of the 24-hour Summer Sun over the Arctic (and Antarctic in its summer) so the snow and ice does not melt and continues to reflect the sun's heat thereby keeping the Earth cooler.  Drawback- a lot of rockets would be needed to have an impact on the tilt of planet Earth which is a very massive body and outer space would become littered with lots more spent-rockets.  This is also likely to cost much more than option 1, but it is a means of achieving less global warming without any ecological side-effects.

3) "Kidnapping" an asteroid in Space and steering it so that it collides with a similar remote tropical island in the Pacific Ocean as (1):  Best if this can be done with the asteroid blasting down in a north-westerly direction mid-afternoon (local time) in April to both reduce the summer tilt of the Earth and push the Earth into an orbit slightly further from the Sun,- both these effects would bring about changes to the tilt of the Earth and strength of the Summer Sun that would help preserve highly-reflective snow and ice-cover.  Vast amounts of dust would be blasted into the stratosphere where it would help reduce the intensity of the Sun at the surface a further 2%.  There would not be problems with radiation fallout but the said tropical island would be obliterated by the impact and this would be very expensive.  But if we can get Tim Peake to the International Space Station we can work on getting a big rocket (with fuel) to an asteroid a mile across and then steering it into the Earth; it is achievable albeit at considerable cost and with considerable technological resources.  I think it is doable if R & D of ££ billions is put into it over a few years!

 

Certainly governments around the World should be directing 0.1% (or more) of GDP into research and development of ideas to combat global warming.        

[iapennell]

I have posted (in the past) some other ideas such as dusting snow-free tropical mountains with salt to they reflect the Sun's heat, damming the far North Atlantic with floatable plastic bridges to stop the warm waters of the North Atlantic Drift reaching the Arctic and assisting ice-melt and pumping sulphur dioxide into the stratosphere to reflect more of the Sun's heat.  All of these, it must be said, would be very costly and would need to be redone regularly, there would be side-effects (sulphur dioxide in the stratosphere could lead to acid rain a few years down the line) so one would need to concentrate on measures that could be done once then (hopefully) need never be done again.

A much more practical measure (which countries could be strong-armed into passing into law) is for global legislation requiring that all new-build and existing urban surfaces be made of white stones or be painted white- that means all roads, buildings, rooves, car-parks, airports, bridges and motorways.  Sure it would take adjusting to (folk will need to wear dark glasses) but if we add up to all urban areas globally we could cut 1% off the heat absorbed from the Sun- buying 30 years of time to gain low-carbon sources of energy.  Farmers could be incentivized to maintain 10% of their land in a brilliant white state by spraying a water-resistant chalk solution (or lime) onto their land three times each year.  For sure there is the cost of the paint (and yes, CO2 would be produced in its manufacture, transport and application) but brilliant white paint on a surface would repay its carbon footprint several times over!

Dust and urban pollution are natural products of the global economy, China and India are good at producing this in vast quantities; Britain, the USA and most European countries were heavy polluters in this regard in the 1950s and 1960s- elderly Londoners will recall the infamous smogs that sometimes afflicted the capital.  However, in passing various Clean Air Acts enforcing companies in the West to clean up their smokestacks the resultant clean air means we have lost a vital buffer against Global Warming as more of the Sun's heat gets through to the surface.  The effect of pollution in the atmosphere when and where the sun is lower in the sky as the Sun's rays pass through a greater length of the atmosphere, thus the loss of man-made aerosol puts Arctic ice and winter/early spring snow-cover over Russia and North America at considerable risk.  We might not like a return to the days when we were choking in smog but we should repeal Clean Air Acts (governments around the World should be strong-armed into doing likewise!) and encourage all factories and homes to put as much smoky pollution of the sun-blocking kind as they like!! The extra aerosol in the atmosphere will knock 0.5C off global temperatures buying another twenty years of time to invest in energy that is not only smoke-free once more but also free of the gaseous pollution of the sort that helps raise (rather than reduce) global temperatures:  In the meantime city-dwellers should be encouraged to buy masks like they wear in some Chinese cities! 

Edited December 27, 2015 by iapennell
correct spelling mistakes, add extra point in post

[cowdog]

13 minutes ago, iapennell said:

All of these, it must be said, would be very costly

 

I normally stay out of these discussion, but I must pick up on this point.

 

None of the suggestions you make would be in your words 'very costly' on a yearly basis for the globe the costs would struggle to go above $100 million a year, as fuel, salt, manpower are all relatively cheap (at the moment). To put into context the UN has a budget of over $5 billion a year.

 

The issue with any geo-engineering system, is that they are unproven and you are in effect 'throwing dice' as no models can accurately predict the outcome.

[iapennell]

14 hours ago, cowdog said:

 

I normally stay out of these discussion, but I must pick up on this point.

 

None of the suggestions you make would be in your words 'very costly' on a yearly basis for the globe the costs would struggle to go above $100 million a year, as fuel, salt, manpower are all relatively cheap (at the moment). To put into context the UN has a budget of over $5 billion a year.

 

The issue with any geo-engineering system, is that they are unproven and you are in effect 'throwing dice' as no models can accurately predict the outcome.

 

@cowdog

Firstly, I hope you have had a good Christmas and all the best for 2016.

Of course all serious geo-engineering solutions are unproven in that they have not been done before.  I do also think the global community does have a little more time to come up with well-researched measures with minimal side effects to counteract Global Warming because the Sun is predicted by a good number of Solar Physicists to enter a Maunder Minimum phase lasting from 2020 to 2060 when the Solar Constant will drop by 0.5% or more and sunspot activity will be very minimal.

However, it is conceivable that solar physicists are wrong about the predicted Grand Solar Minimum; it is impossible to send probes to investigate the interior workings of the Sun (which is over 1 million degrees C) without their being destroyed and the predictions are based on little more than observing past Sunspot Cycles- so we could all be horribly surprised.  To that end the global community should stop wringing its hands; this Paris Summit was a commitment to keep global temperatures from rising over 2C above pre-industrial levels and this is only practically achievable by cutting CO₂ emissions globally by 80%:  Realistically this is only absolutely achievable by decimating the global economy and condemning billions to penury through high "green taxes" to pay for more windmills, solar panels, geothermal energy, investing in "electric cars" and so forth. I am not saying that R & D should not be poured into green energy sources but to reduce CO₂ emissions globally by 80% by 2020 would cost ££ trillions and decimate industries and cause millions of job-losses.  Governments around the world would come up against their respective electorates very quickly and be forced to change track- this is neither realistic or practical!

We are then likely to be left in a situation (certainly by the 2060s, possibly rather sooner if the new Grand Solar Minima fails to materialise or is weaker than predicted) where Governments are left wringing their hands in despair as global temperatures increase above the "2C warmer than pre-industrial" threshold and severe summer droughts and killer-heatwaves hit Europe, Russia and North America whilst rising sea-levels swamp London and New York as Greenland's ice melts away in large quantities.  We have to look at other measures to bring global temperatures down from dangerous levels, I would assert the risks of doing nothing are much greater.  Painting cities white, allowing aerosol pollution don't require major global collaboration of resources and technology, just some changes in legislation as much as anything but doing nothing is not really going to be an option as the years pass.