K, I was thinking some more about the 10,000 times as much energy from the sun as we produce. Assuming that number is correct, and I guess it is within an order of magnitude or two, there is something we can conclude from it and it's not a happy conclusion [from my point of view though most people would think it a good thing].
I have ranted many times that we are saving ourselves from the ice age and another lapse back into the big freeze. There is pretty good evidence that we are doing just that.
We have definitely got the atmospheric CO2 levels up somewhat, albeit a disappointing amount after a century of effort and having consumed a huge amount of hydrocarbons and coal. Temperatures are only up a fraction, so we certainly haven't achieved much in the way of warming, though perhaps without the effort, it would already be glaciated over much of the northern hemisphere.
But we are going to struggle to keep that effort up over the next century and the ocean is constantly draining our efforts as CO2 is absorbed, fed through the food chain and dumped on the bottom of the ocean to go into radiolarian ooze and ocean crust sediment being trundled across to subduction zones after a million years or so.
What we can conclude from how little energy we are producing compared with how much is coming in and is absorbed by plants is that we are pissing in the ocean, to use a vulgar expression, or farting against thunder, to use another, in our efforts to boost CO2 levels and prevent a return to glaciation.
If you take a look at Earth from space, it's got a LOT of green on it, and the ocean has a lot of green too. That green is very busily turning CO2 into cellulose and plant stuff. The plants go through the food cycle and end up at the bottom of the ocean as shell and bone and some trapped organic goop.
I've just been looking at photos of Earth from space and I'm having to revise my estimates of how much green there is. This picture has got a LOT of desert and semi desert on it: gearthblog.com
But just for estimation purposes, let's guess land-based green at about 10% of land area. In NZ it's over 90%, but in Australia it's more like 10% if that. Europe across the temperate zones to Japan is pretty high at about 40%. Same for North America. But nearer the equator there is a LOT of brown and especially in summer.
Oceans are dead in a lot of places for lack of iron and other nutrients, so algae and green stuff can't get going in a lot of it. Most of the light landing in the ocean is simply absorbed as heat, not by chlorophyl.
So, maybe 10% at most of the energy coming in gets nabbed by chlorophyl and only 30% or so of that light turns to plant.
So, maybe 1% of the incoming sunlight turns to plant and enters the food chain.
That means our efforts are something like 1% of the plant energy. Which is still puny. It means the plants can absorb CO2 a LOT faster than we can put it out, if they can get hold of it. Much of the CO2 we produce just swirls around in the upper atmosphere with plants battling to collect the thin gruel at the surface. Optimum CO2 for most plants with a good nutrient supply is more like 1000 ppm, or 1500ppm, than the current 380ppm.
Although CO2 output has been continuously increasing for a century, CO2 levels are only increasing at a linear rate, meaning the more we put out, the faster it is being absorbed. For thirty years, the rate of CO2 increase in the atmosphere has been linear, though CO2 production has continued to increase. cdiac.ornl.gov Before that the rate of CO2 accumulation in the atmosphere was increasing, from 1954 to about 1980.
The basic principle is that filling a leaky bucket gets more difficult the fuller it gets, because the rate of leakage continues to increase. Chemical reactions work the same way - increasing the concentration at the start of a process increases the rate of chemical reaction. More CO2 surrounding a leaf means more CO2 can get into the stomata each gulp of air [not that plants gulp, that's literary license].
My guess is that we'll get tired of producing CO2 before plants get sick of gobbling it up. So far, with huge oil and gas fields sitting conveniently in gusher form, we have had an easy time of it. With improved exploration and production techniques, we are able to develop what would have been impossible fields and do it cheaply enough to do more of it.
We haven't even started on Orinoco heavy crudes, vast coal reserves and have barely touched Athabascar. Saudi Arabia, Iraq and Iran still have stupendously huge reserves, but Islamic Jihad loom large there. Nevertheless, we should be able to keep doing what we are doing for another 30 years or so, by which time we might have got CO2 up to about 430 ppm, which is still far from optimum growth rate for plants and will only reduce athletic performance by a small amount. It will be good for the biofuels industry and crop growers. It'll reduce irrigation requirements too and that's good for places where water is expensive.
If we want to, we could send fishing boats out with iron and other algae nutrients to boost the oceanic biosphere by feeding algae. While they trawl for fish, they could disperse the nutrients. Put the fish in the nutrient tanks for the return to base. Or, more simply, disperse nutrients from land into passing oceanic currents.
The ocean is the big absorber of light, so giving algae something to work on would create a vast aquaculture industry, and fish is very good for people to eat.
At some stage in the next 100 years or 200 years, our hydrocarbon production will decline and the plants and animals will relentlessly keep stripping the CO2 out of the atmosphere and dumping it at the bottom of the ocean. My guess is we'll reach peak human CO2 output about the same time as Peak People and Peak Oil are reached. As a guess, I'll pick 2037 as the maximum. If I'm very lucky, I'll be one of the baby boomers still around to see what happens.
My guess is Peak People, Peak Oil and Peak CO2 output will all happen in the same year.
There's no way people will be able to keep CO2 going at current rates into the 22nd century. When we finally run out of puff, plants will carry right on stripping it out and my guess is that the ice age will reassert itself in the 22nd century and a lot of people alive now will be alive then to witness it. They will move to Africa.
The ice age might return sooner, despite our excellent efforts on CO2, given the limited temperature increase we have achieved in a century of intense efforts in CO2 production. Which would be a LOT of fun. It should flip to glaciation in as little as 3 years if it happens, because snow reflects, cool makes clouds, clouds reflect and make more snow, which reflects, making summer cooler and snow start sooner and buries plants which adds to reflection and plants in the deserts can't get going so quickly, being still dry there, with moisture coming out as snow in the high latitudes. The cooling feedback loop is very fast. Warming and glaciation retreat is not so fast because it takes time to melt a kilometre of ice, even if air temperatures go up quite a lot.
That's the executive summary.
Mqurice |
