The Greenhouse effect is like an ordinary green house. The sun's light comes through the glass mostly in the visible range. The ground inside is also radiating but in the Far infra red that we cannot see and cannot get through the glass. So the inside heats up. In the atmosphere instead of glass sheets we have water vapour, CO2 and CH4 which is methane. All these block parts of the infra red radiated by the Earth.
The albedo is different, it is the reflectance of the surface, the land and the seas. These are quite bad reflectors. Ice and clouds are quite good reflectors as is white paint and of course mirrors.
Yes! Carbon offset is where a CO2 producer can justify doing that by doing a CO2 reducing activity. One of the best known is planting trees. A dollar value is allocated.
This project, like any albedo reducing project is a genuine carbon offset activity. Indeed the projected cost is much less than the sums now being set aside to compensate people and nations suffering from global warming.
If you look it up you find a brand of wafflle, but the word croffle was originally reserved for hollow balls used to stop evaporation from lakes and ponds.
Perhaps the American name "shade ball" is more descriptive, but croffles do not have to be balls.
They can be made of various plastics, metal or glass and they form a floating layer on, say, a reservoir where they greatly reduce evaporation.
In this proposal the croffles or shade balls are made reflective so they bounce sunlight back outwards.
It might increase rainfall in California. The extent is hard to predict. The shade balls would spread out or can be encouraged to spread by their design. So evaporation would not stop and the general area is large.
We do not want to make the plastic debris problem worse! The white loading of the plastic reflects nearly all the light, especially the UV light that damages plastics. This is very important and the Croffles must be shown in the pilot study to last many years in the strong sunlight of the Pacific. The target is ten years but thirty years would be better. Glass croffles would last much longer unless they smash. And smashed glass would sink to the bottom which is already silicates (sand) Glass is a silicate. Aluminum cans would survive. A mixture of metal, glass and plastic croffles may be the best floating mirror.
In most parts of the oceans the Croffles would drift about. They still work as mirrors wherever they are. But in the chosen patch, the currents trap floating objects permanently even with winds blowing. Part of the pilot phase is to monitor what they do. If they wander they will do so for many years but eventually would wash up on shores. In 1992 a cargo of about 29000 bath plastic ducks was lost at sea. That was in the Northern Pacific, North of the rubbish patch. They are still turning up all over the place, thirty years later.
That is a good question. The consensus has been on Carbon emission control to limit CO2. Good progress has been made on reducing Methane leakage but CO2 continues to rise from burning coal, oil and gas, plus wood burning and forest fires.
The focus on reducing CO2 has pushed all the ideas about geo-engineering onto the back burner where there are quite a few ideas to be found. Whatever project is attempted will cost billions of dollars because the scale will always be huge.
The scale of any geo-engineering project has combined with worries about negative effects. And unintended consequences. These are fair points but meanwhile the situation has got worse.
It is the Methane story that should be the most concerning because methane has a short life in the atmosphere, only twelve years, and yet it is climbing rapidly. so more is being released from wetlands thanks to the warming that already occurred. Then the loss of ice and the changes to cloud cover have reduced albedo. This is a runaway situation that will not be solved by good intentions on CO2 reduction.
Reducing carbon use means actual restrictions on developed economies. But this kind of project, expensive as it is, means more jobs, more investment and has a positive outcome giving the world more time to deal with Carbon.
Time is the issue, the rate of warming is now rapid and we have only a few years to put it right.
Right now the difference between the sun energy coming in and the radiated energy going out is about 1%. The Earth surface has to heat up to get back into balance. It is heating up. This has happened in the previous millenia too.
That historically pushed Earth into a hot phase that must have killed off plant life, stopping the CO2 and Methane so that the poles froze into ice ages.
But now humans can make a mirror to reflect a different 1% directly out to space, to compensate for the elevated CO2 and CH4. We can make that difference and then evermore control the climate by geo-engineering.
The future will include many geo-engineering projects to fine tune the climate, cloud control, rain control and of course limits to carbon use and carbon capture.
We can say it started years ago. Humans were burning forests, then invented the industrial revolution by getting energy out of fossil fuels. That was unintentional geo-engineering. Science has shown how it was the steady rise of CO2 that increased the natural greenhouse effect.
There have been suggestions to inject Sulphur dioxide into the upper atmosphere where it becomes sulphuric acid. The sulphur is a negative greenhouse gas, but acid rain and ozone depletion could be side effects.
You can cherry pick predictions, and many climate predictions have not been fulfilled. But other climate predictions have been consistent. One of interest is the way climate models cannot predict extreme events.
The models have progressively used smaller grids and their weather predictions have improved. But while general statements about those events support the increased frequency they cannot say where and when. I am just looking at the present and comparing it with the ice age record. But also commenting on the ongoing concentration on CO2 control which is obviously not happening.
Geo-engineering was always a possible response, to increase albedo, but it has so little traction. The argument presented here is to show the scale of the problem and the feasibility of a solution. The prediction of huge spend on adaption, now measured in trillions of dollars, is realistic and ignores the cheaper cost of geo-engineering.
One prediction to watch is the weakening of the AMOC, if that stops, it is too late, probably.
It is fair to point out that plastic bottle manufacture is offset by recycling the plastic. My point here is that manufacturing scale exists now in both plastic and aluminium.
As to recycling the croffles, that is also a fair point. Not yet addressed because we do not know the average life. The recycling argument favours glass, in that huge amounts of coloured glass go to waste and broken glass croffles would just sink harmlessly to the ocean floor. Glass can be made white and does not degrade in UV at all. there is only the issue of breaking on impact. The pilot project will examine that. A fully glass croffle mirror is a possible outcome, just because of the recycling issue.
Sealed aluminium cans are also possible.
The pilot can include existing croffles, bottles and cans because those are already made in billions. There is also the possibility of special designs such as circles of aluminum or stainless steel, welded around their edges and partially inflated, so they float as round mirrors. But those might require costly tooling to mass produce, even if effective at small scale. Only a sea trial can check which design should be mass produced.
The various orbital cycles have dominated our long term history, but that was without our recent industrial past. It is easy to cast the environment as a long term cycle but here we are in a crisis. At the end of the ten thousand year holocene period, we "homo sapiens" dominate the planet. we have elevated CO2 way above the last ten thousand years' levels and the levels seen in the ice cores. The CO2 warming has elevated CH4, methane, into and beyond the levels seen in the previous millenia.
Deniers claim that is that this is just a natural phase. But we are not in a natural phase, we are changing the rules. The rising Methane and falling Albedo are real current issues. The prehistory story includes collapse into ice ages when CO2 and CH4 are this high. We are living in the current era so we must use the current environment as our evidence. Extreme events are becoming more common. We can expect global warming to continue towards an unsustainable peak, as has happened before, before we were able to make a difference.
There are voices saying this is just a natural cycle, but it isn't. That meme represents a risk. We have agency if we choose to use it. We can take control of the global heating cycle.
We have elevated CO2 and CH4 above previous ice age records. We are reaping the whirlwind, but we have the means to correct and control it. Increasing albedo is the short term fix while we work out how to control the greenhouse.
A mirror in the desert would work too. But the scale has to larger. That is because the albedo of a sandy desert is higher at over 40%, even as high as 49%. So we could only expect to double it using mirrors. So the area using this simple guideline would have to be five times larger. Like the size of Texas. Clay or slate tiled Rooves are darker, they can be painted white or covered with mirrored sheet.
No. The warming el Nino events are about every seven years while the solar cycles are about every eleven years. We are in an elNino event now (2023-2024).
However, the coming solar maximum in 2025 will add to the warming effect because more energy comes from the sun.
The AMOC is a major ocean water circulation. It has different causes from the Gulf Stream, which will not falter.
The AMOC carries tropical hot water toward the Arctic, warming northern Europe. It is driven by cold salt water sinking near Greenland and Antarctica and these drivers are getting weaker because of fresh water ice melt. The whole circulation includes the Indian Ocean and the Pacific plus the southern ocean so really all the Earth's waters. It is weaker than before and no one knows if it will stop, but a recent study published in Nature has shortened the odds and the timescales. It might weaken a lot from 2025 to 2095, centred on 2057.
The consequence for Europe will be a rapid cooling to a climate more like Eastern Canada. But the whole world will see changes like hotter tropics, more rain in Australia and so on. Higher sea levels for the USA East coast, in all a major disruption with hard to predict duration and consequences. It could start an ice age.
This is another urgent wake up call for cooling, and only geo-engineering can act fast enough. The AMOC collapse would accelerate all the destructive outcomes to our civilisation in a few years. It begins the cycle toward another ice age, which may seem counterintuitive. But the ice core record shows stable ice ages after each hot Earth period. That prediction is only 34 years ahead!
That question reveals a major benefit of this idea. The floating croffles area can be increased or reduced by surface ships. So it is reversible and easy to monitor in the coming years. Croffles can be removed by fishing nets.
We have about twenty years to geo-engineer the albedo.
Otherwise the AMOC will weaken. That will start cooling and the albedo will then increase by itself as the Earth goes into a cooling towards an ice age.
The climate will become hard to predict but many people will die of starvation, disease and conflict.
The ice age will be impossible to stop once it starts, while right now we can hope to manage the albedo to stabilise the Holocene, (that is the last ten thousand years of benign climate).
Ice ages last more than a hundred thousand years, who can say what human society will do?
The key climate issue is probably the weakening of AMOC.
If we progress toward hot Earth conditions as in the historical record, the sea levels will be higher, the tropics will be very hot. If the gulf stream stops, the sea levels will fall; current political systems will not cope in either case.
I think we should geo-engineer.