Isn't it strange that the world has managed all the years since the last Ice Age without the climate running amok? There have been big swings in inputs of heat with solar radiation changing, albedo has been elevated by volcanic dust, agriculture has torn up native vegetation. In the past, things settled back down. This time it doesn't look as if they will. Here's what's happening in the Northern Hemisphere as shown in the famous 'hockey stick graph'. Just look at it -- it frightened me stiff when I first saw it, and even though I've since read refutations of the methodologies used to derive it, it still does (see http://news.bbc.co.uk/1/hi/sci/tech/4349133.stm ). Regardless of the problems about knowing past temperatures, measured temperature is steadily rising (look at the red line on the graph). Something is going on.
Here is the current scenario:
1. CO2 levels are rising: this is measured and is happening in the real world, not in the extrapolations and equations of climatologists. The CO2 is trapping heat and raising the temperature.
So far, so agreed.
2. The rise in CO2 is because humans are producing more and the world is unable to absorb it fast enough to prevent the levels going up.
OK.
3. Temperatures may reach a tipping point where runaway greenhouse warming occurs, because methane deposits (frozen in tundra and as clathrates in cold oceanic depths) will release vast amounts of this most potent greenhouse gas.
Not just OK, frightening.
4. The oceans will become acidic as they absorb more CO2.
Substitute 'less alkaline' for 'acidic' and I can live with this. As they already contain fifty times more CO2 than the atmosphere, the oceans can take quite a bit more before they start dissolving shellfish.
5. The only cure is to curtail our production of CO2.
Well, no... Not until certain questions have been addressed.
Some questions and answers:
1. Is there a bottleneck on the absorbtion of CO2 by any or all of the absorbing mechanisms?
1A1. Tree-felling is high on the list, as is farming. But one would expect the oceans to be able to up their biological activity and take up a lot more. Fertilising with iron has been tried and produced some exciting results. Maybe iron is the limit to the oceans' ability to turn excess CO2 into biomass.
2. What other cooling mechanisms have been disturbed by humanity?
2A1. Low level clouds cool the Earth by reflecting heat back into space. Clouds form droplets around hygroscopic nuclei -- it is surprisingly diffcult to form droplets unless they have something to start them off as anyone who has operated a cloud chamber will testify -- and a reduction in nuclei will decrease cloud cover. We've pumped out megatonnes of sulphur dioxide since the start of the Industrial Revolution, perfect cloud makers. However, this should have cooled things until we became worried about acid rain and curbed these emissions. Ironically, we may have exacerbated one problem by addressing another (and, incidentally, the sulphur has been holding back methane production in the arctic -- when the sulphur brake comes off we'll see an uptick in methane and another panic).
2A2. High level clouds hold heat in. Next time you see a high level airliner leaving a long white trail in the sky, think of it as a blanket. Is it big enough to make a difference? Don't know.
3. Can we improve any cooling mechanisms?
3A1. Yes. Trees do it (not as well as once thought, but they do it better than a clear-felled wilderness of burnt scrub being slowly washed away by tropical rainstorms).
3A2. Yes. Fertilise the oceans (see above comments about iron).
3A3 Yes. Mechanically produce hygroscopic nuclei.
http://www.ccc2006.ca/docs/Abstracts.pdf
4. Is there anything else?
I'm glad you asked that... 3A3 above is a very appealing answer to our problems as it uses seawater to produce the cloud-stimulating nuclei, non-polluting, efficient and actually within our reach if things get desperate. But where do the nuclei come from normally?
Some are produced by plankton. As it gets warmer these small floating plants produce more DMS ( http://www.uea.ac.uk/~e061/ ) in a promising feedback.
Some are produced mechanically. Wind stirs the surface, wavelets and waves form and break, bubbles are driven down into the water and droplets are driven into the atmosphere. The bubbles exchange gas with their surroundings, pumping excess CO2 from above into the main body of the ocean. Tiny droplets dry and form nuclei. 30% of the ocean is covered with low clouds condensing around these nuclei. Now we come to it. Surfactant pollution of the ocean surface reduces wave formation (think of oil on troubled waters and you'll get the general idea). It therefore reduces entrainment of atmospheric gases and suppresses production of hygroscopic nuclei.
Surfactants have been produced by the petrochemical industries as detergents and as by-products for the last 150 years. Small amounts of surfactants can cover very large areas of water surface. Biological processes break down surfactants if they are not too resistant -- older surfactants were not biodegradeable and older readers will remember weirs foaming downstream of overloaded sewage treatment works. 0.1% of oil production is currently turned into surfactants, but I cannot find the amounts which might persist long enough to have an effect on the climate.
Oil spills reduce wave formation. 0.25% of total oil production is spilt on the oceans every year. Yes, 0.25%! A lot of that will be thick tar, but a lot will be light oil. Tiny amounts of light oil cover huge areas.
If surfactants and oil spills have reduced the ability of the oceans to take up CO2, there should be an imbalance between blue ocean pH values and the atmosphere. I cannot find out if this is the case. pH changes have been measured -- but in a bay where wave mixing is pretty well assured and the surfactant/oil sheen effect would not show up -- and the RS paper on acidification of the oceans talks of 'using models' to produce its apocalyptic result. Not being over-trustful of modelling in this instance, I'd like to see sample bottles being tested. Here again the web is dumb. Sites are full of caveats such as 'this research is difficult to carry out in the field'. However, I've seen one calculation that 2 gigatonnes of CO2 are left in the atmosphere because of this effect. A gigatonne here, a gigatonne there -- pretty soon we're talking big numbers. Have a look at http://gesamp.imo.org/index.htm : it's out of date and talks only of natural surfactants, but it's the best I can find.
If surfactants and oil spills have reduced the ability of the oceans to produce hygroscopic nuclei and hence to seed low level cloud formation, there should be a measurable reduction in cloud cover. Does this data exist? I can't find it and, since the problem predates satellite data, it may well be that it does not exist prior to the sixties. But it might be a good idea to check the last forty years' worth of oceanic photographs.
What would show in the historical record if a major oil deposit was suddenly breached by the sea and produced a huge pulse of light crude onto the surface of the world's oceans? I don't know. I suspect the data might look like the graph above.
Do the graphs of warming and increased DMS production cross and offer an upper limit to the warming process? Don't know. If we stop polluting the ocean surface with surfactant/oil, will the increased DMS and improved mixing produce an over-correction, leading to rapid and damaging cooling? Don't know, but I'd bet on it, because life's like that. But it's best to try -- I really don't like the look of that graph.
And another thing: plankton blooms can be monitored by satellite and offer a way of predicting earthquakes: in a recent (9 May 2006) report the authors say that the chlorophyll blooms are linked to a release of thermal energy prior to an earthquake. This causes the sea surface temperature to rise and increases the surface latent heat flux - the amount of energy moving from the surface to the air due to evaporation, and in turn, there is enhanced upwelling - the process by which cold, nutrient-rich water is transported from the deep sea to the surface. Reducing evaporation from the surface will reduce upwelling and lead to a suppression of plankton production. Oil film and surfactant pollution both reduce evaporation. Plankton pulls CO2 out of the atmosphere as well as producing DMS, so this is a double whammy effect, fewer clouds, less CO2 consumption..
1. CO2 levels are rising: this is measured and is happening in the real world, not in the extrapolations and equations of climatologists. The CO2 is trapping heat and raising the temperature.
So far, so agreed.
2. The rise in CO2 is because humans are producing more and the world is unable to absorb it fast enough to prevent the levels going up.
OK.
3. Temperatures may reach a tipping point where runaway greenhouse warming occurs, because methane deposits (frozen in tundra and as clathrates in cold oceanic depths) will release vast amounts of this most potent greenhouse gas.
Not just OK, frightening.
4. The oceans will become acidic as they absorb more CO2.
Substitute 'less alkaline' for 'acidic' and I can live with this. As they already contain fifty times more CO2 than the atmosphere, the oceans can take quite a bit more before they start dissolving shellfish.
5. The only cure is to curtail our production of CO2.
Well, no... Not until certain questions have been addressed.
Some questions and answers:
1. Is there a bottleneck on the absorbtion of CO2 by any or all of the absorbing mechanisms?
1A1. Tree-felling is high on the list, as is farming. But one would expect the oceans to be able to up their biological activity and take up a lot more. Fertilising with iron has been tried and produced some exciting results. Maybe iron is the limit to the oceans' ability to turn excess CO2 into biomass.
2. What other cooling mechanisms have been disturbed by humanity?
2A1. Low level clouds cool the Earth by reflecting heat back into space. Clouds form droplets around hygroscopic nuclei -- it is surprisingly diffcult to form droplets unless they have something to start them off as anyone who has operated a cloud chamber will testify -- and a reduction in nuclei will decrease cloud cover. We've pumped out megatonnes of sulphur dioxide since the start of the Industrial Revolution, perfect cloud makers. However, this should have cooled things until we became worried about acid rain and curbed these emissions. Ironically, we may have exacerbated one problem by addressing another (and, incidentally, the sulphur has been holding back methane production in the arctic -- when the sulphur brake comes off we'll see an uptick in methane and another panic).
2A2. High level clouds hold heat in. Next time you see a high level airliner leaving a long white trail in the sky, think of it as a blanket. Is it big enough to make a difference? Don't know.
3. Can we improve any cooling mechanisms?
3A1. Yes. Trees do it (not as well as once thought, but they do it better than a clear-felled wilderness of burnt scrub being slowly washed away by tropical rainstorms).
3A2. Yes. Fertilise the oceans (see above comments about iron).
3A3 Yes. Mechanically produce hygroscopic nuclei.
http://www.ccc2006.ca/docs/Abstracts.pdf
4. Is there anything else?
I'm glad you asked that... 3A3 above is a very appealing answer to our problems as it uses seawater to produce the cloud-stimulating nuclei, non-polluting, efficient and actually within our reach if things get desperate. But where do the nuclei come from normally?
Some are produced by plankton. As it gets warmer these small floating plants produce more DMS ( http://www.uea.ac.uk/~e061/ ) in a promising feedback.
Some are produced mechanically. Wind stirs the surface, wavelets and waves form and break, bubbles are driven down into the water and droplets are driven into the atmosphere. The bubbles exchange gas with their surroundings, pumping excess CO2 from above into the main body of the ocean. Tiny droplets dry and form nuclei. 30% of the ocean is covered with low clouds condensing around these nuclei. Now we come to it. Surfactant pollution of the ocean surface reduces wave formation (think of oil on troubled waters and you'll get the general idea). It therefore reduces entrainment of atmospheric gases and suppresses production of hygroscopic nuclei.
Surfactants have been produced by the petrochemical industries as detergents and as by-products for the last 150 years. Small amounts of surfactants can cover very large areas of water surface. Biological processes break down surfactants if they are not too resistant -- older surfactants were not biodegradeable and older readers will remember weirs foaming downstream of overloaded sewage treatment works. 0.1% of oil production is currently turned into surfactants, but I cannot find the amounts which might persist long enough to have an effect on the climate.
Oil spills reduce wave formation. 0.25% of total oil production is spilt on the oceans every year. Yes, 0.25%! A lot of that will be thick tar, but a lot will be light oil. Tiny amounts of light oil cover huge areas.
If surfactants and oil spills have reduced the ability of the oceans to take up CO2, there should be an imbalance between blue ocean pH values and the atmosphere. I cannot find out if this is the case. pH changes have been measured -- but in a bay where wave mixing is pretty well assured and the surfactant/oil sheen effect would not show up -- and the RS paper on acidification of the oceans talks of 'using models' to produce its apocalyptic result. Not being over-trustful of modelling in this instance, I'd like to see sample bottles being tested. Here again the web is dumb. Sites are full of caveats such as 'this research is difficult to carry out in the field'. However, I've seen one calculation that 2 gigatonnes of CO2 are left in the atmosphere because of this effect. A gigatonne here, a gigatonne there -- pretty soon we're talking big numbers. Have a look at http://gesamp.imo.org/index.htm : it's out of date and talks only of natural surfactants, but it's the best I can find.
If surfactants and oil spills have reduced the ability of the oceans to produce hygroscopic nuclei and hence to seed low level cloud formation, there should be a measurable reduction in cloud cover. Does this data exist? I can't find it and, since the problem predates satellite data, it may well be that it does not exist prior to the sixties. But it might be a good idea to check the last forty years' worth of oceanic photographs.
What would show in the historical record if a major oil deposit was suddenly breached by the sea and produced a huge pulse of light crude onto the surface of the world's oceans? I don't know. I suspect the data might look like the graph above.
Do the graphs of warming and increased DMS production cross and offer an upper limit to the warming process? Don't know. If we stop polluting the ocean surface with surfactant/oil, will the increased DMS and improved mixing produce an over-correction, leading to rapid and damaging cooling? Don't know, but I'd bet on it, because life's like that. But it's best to try -- I really don't like the look of that graph.
And another thing: plankton blooms can be monitored by satellite and offer a way of predicting earthquakes: in a recent (9 May 2006) report the authors say that the chlorophyll blooms are linked to a release of thermal energy prior to an earthquake. This causes the sea surface temperature to rise and increases the surface latent heat flux - the amount of energy moving from the surface to the air due to evaporation, and in turn, there is enhanced upwelling - the process by which cold, nutrient-rich water is transported from the deep sea to the surface. Reducing evaporation from the surface will reduce upwelling and lead to a suppression of plankton production. Oil film and surfactant pollution both reduce evaporation. Plankton pulls CO2 out of the atmosphere as well as producing DMS, so this is a double whammy effect, fewer clouds, less CO2 consumption..
Surfactant runoff and oil spills are reducing the ability of the ocean to absorb atmospheric gases and to produce cloud forming nuclei. So CO2 levels are increasing and the Earth's albedo is decreasing. This makes it warmer.
Stop polluting the ocean surface.
errr....
That's it.
21 Feb 06
errr....
That's it.
21 Feb 06
UPDATE ON 5 FEB 2007
The hockey stick graph frightened me: it was clear, scientific and explained what was going on. Later investigation has made me less certain about the historical (ie pre-thermometer) bits of the graph, but looking at the instrumental part still frightens me. Man-made or not, something is going on.
I was puzzled by the assumption that the CO2 driving the warming is anthropogenic: in a system with such a huge turnover, our paltry contribution could not, surely, be able to have such a large effect. There must be, I thought, some leveraged system that we had disrupted, something comparatively small where small inputs produce large effects.
Three quarters of the world's surface is covered with water (lovers of the ancient TV programmes of Hans and Lotte Hass can supply their own accents here), and that liquid surface is mobile, able to spread our effects almost as readily as the atmosphere. It gives off the major greenhouse gas in such abundance that I could, and can, see no way that we could change the contribution of water vapour to the greenhouse effect. As well as sending water into the air, the oceans also give off reflected radiation and hygroscopic nuclei. Di-methyl sulphide comes from plankton. Low level stratocumulus cloud forms on these last two which reflects sunlight, making the water beneath cooler than expected.
THE TIMELINE
Mauve was invented around 1850. The petrochemical industry began to spill oil and flush surfactants away down the rivers, happily growing at an exponential rate as they struggled to meet the demand for their new products. Whale oil became old-fashioned and oil wells pumped day and night to meet the new demands for lamps, steam-ships, cars. Hygroscopic particles were still produced but in fewer numbers -- a surfactant or oil sheen polluted wave is smoother and less likely to break. Less physical mixing reduced the incorporation of CO2. A small uptick in CO2 began and gathered strength.
Low level cloud cover dropped, a little here, a little there, as less salt was thrown into the air. Albedo was lowered and more energy fell on polluted seas. The water column became more stable. Upwelling was reduced by a small amount and, infinitesimally, the blue desert areas of the deep seas spread. Plankton, used to the good life with nutrient rich water coming up from the depths, found themselves short of zinc and chromium which they need to proces carbon. Some phytoplankton can switch from the C3 to C4 metabolism, zinc and chromium free, and this latter system fractionates the isotopes less than the former. Isotope ratios in the atmosphere changed as the C4 phytos rained out more of the heavier atoms incorporated into their structures. Obligate C4 phytos gained ground over their starving cousins.
The deep-sea currents warmed almost imperceptibly and deep-ocean methanophage bacteria, clustered in the silt around the methane clathrates, perked up and began to devour the ancient deposits at a slightly faster rate. Light isotope CO2 bubbled up to further confuse the isotope calculations of those who believe that there can be no other source of light CO2 than the burning of fossil fuel.
The polluted areas spread. The first synthetic surfactants hit the market in the late forties, tough, resistant to breakdown. Today enough oil comes down the sewers every two weeks to spread a layer a few molecules thick over the entire world ocean. Albedo is still falling. CO2 levels are increasing and the greenhouse effect is going to cause problems, perhaps even accelerating problems. The clathrates are being devoured slowly, but if the temperatures get too high down there we will really need a large paddle to get out of the creek. It would be nice to know if there is anything we can do. The risk is the clathrates: the PETM shows what happens if they degrade.
Salter, Latham et al have proposed a system of spraying sea water in such a way as to generate clouds, increasing albedo. Cheap, much more flexible than other proposals -- you can turn the sprays off and the albedo drops almost instantly to its previous level -- it's surprising that it has not attracted more attention. A useful side effect of the proposal is that much of the mathematical spadework has been done. We can back-calculate how great the albedo reduction caused by pollution (or, in fact, how small in this case, it's tiny) would need to be for this hypothesis to have legs.
WE CAN DO THE NUMBERS
It is said that we cannot experiment on the climate. We don't need to, not in terms of the surface pollution hypothesis of global warming, as the experiment has already been done. In WWII, millions of tons of shipping was sunk, mainly in the North Atlantic and selected areas of the Pacific. Albedo would have dropped abruptly and, at the end of the war, risen with equal speed. The signal should show in the record. There may be difficulty with the increased CO2 output (and increased oil spill) from industry gearing up for war, but this can be eliminated by looking at the end of conflict and assessing the .3 deg drop in temperature as the ocean struggled to regain its balance with the last dregs of light oil leaching out from the heavy bunker oil used by merchant ships.
We can do the science: we can look at past warmings and search for isotope ratio changes, we can search the temperature records and seek out small signals like the oil shock of 1973, WWI, even tiny contributions like very large bulk tanker spills. We can calculate how our current warming would look if we used the same methods we apply to past warmings. We can check for isotope changes in deep sea ooze.
We can look at the surface of the ocean and measure how polluted it is. We can experiment and see how that level of pollution effects the various processes which matter to climate. Experiment, by the way, means getting wet, splashing, getting dirty. It doesn't mean measuring a few parameters and running equations through a supercomputer.
Some things don't change: CO2 still increases and causes greenhouse warming. Sea levels rise. The deep thermohaline circulation still threatens to react. But these things are incorporated into a coherent narrative: to find out if it is a true story we need to do the science. But that is true of the current theory which claims that our CO2 production is somehow different, somehow uniquely damaging to a system that has been turning over that amount every few days for the last 500 million years. Models of a complex and little understood system (check how many areas of climate science are understood to a low or very low standard and look at the huge error bar on the estimates for the contribution of cloud forcings) are not science, but they can suggest where science should look for the numbers.
I find this hypothesis an intriguing narrative. Is it right? I don't know, as we have not done the numbers. Is the anthropogenic CO2 production hypothesis convincing? I don't know. It seems to me to be just another narrative, intriguing, perhaps even right, but I wouldn't bet civilisation on it. Stopping industry is only going to happen if the science is right. Is it right? Are you ready to bet on it?
Me? Not yet. I'd clean up the oceans first and see how that worked out.
JF
Note: I would be delighted to discover that a stilling well under-reads during a storm. If it did then we could even cover the sea level rise part of global warming. I leave the logic to the thoughtful reader. It's not really important to the hypothesis, but it would be fun to cover another bit of the puzzle.
While you're thinking, look up the Paleoscene-Eoscene Thermal Maximum (PETM) and imagine how it could have been caused by erosion of an oil-bearing deposit over a few hundred years, or even just a decade or two. If you've got a few million to spare you could get a team to search for a strange isotopic signature. Hurry. If I'm right then here is where we're going:
http://en.wikipedia.org/wiki/Paleocene-Eocene_Thermal_Maximum