Tuesday, September 30, 2008

On Global Warming

These days I find myself worrying a lot about matters of global importance. Climate change for instance, I feel is too important an issue to be left to scientists and politicians. All that you see on the TV and hear on the news about global warming is what the politicians want you to see and hear. And the solutions that they promote may not exactly solve the problem. So, what is required here is a dry, scientific analysis of the situation.

Let us understand the phenomenon of global warming. In a nutshell, there is a layer of various gases around the earth called the "atmosphere". Carbon-dioxide is an important component of this "atmosphere" because it traps the heat from the sunlight and keeps the planet warm. But having too much Carbon-dioxide in the atmosphere is no good, because then the planet would get too hot. Consequently, the polar ice-caps and glaciers would melt, causing the sea levels to rise. This means some of the coastal places and islands would submerge in water. And polar bears would die.

This is exactly what is happening in the world today. Due to some reason, the sunlight trapped in the atmosphere is not able to escape back into space. And that is causing a lot of worry.

First, let us get a few basic things straight.
More Carbon-dioxide is bad.
Furry animals are good. We want more of those.
More water is bad.
Trees are good.
Heat is bad. We don't want any more warmth.
More land can be good or bad, depending on which side of the Norwegian Sea we are talking about.

All that remains now is to tie up the equation neatly.

The amount of carbon present in the world is more or less constant. The forms in which it is present vary greatly over time. Till a hundred years back, there was a lot of carbon trapped in the soil in the form of coal and petroleum. But over the years, it has been dug out and burnt up, and as a result it has been converted to gaseous form. It is this gaseous form which is harmful to the planet. As long as the carbon is in liquid or solid state, all is fine. But when more and more carbon is released into the atmosphere from the soil, it starts to be a nuisance.

A good plan to cool down the planet should also deal with the problem of carbon sequestration; that is conversion and storage of carbon dioxide in liquid or solid form, thus driving down the CO2 level in the atmosphere. So anything that converts the gaseous CO2 into liquid or solid form is good. Oceans, for instance. Carbon dioxide dissolves in the ocean water to form carbonic acid. Thus oceans help to clean up the atmosphere by condensing the carbon into a liquid form. Carbon dioxide reacts with calcium oxide to form limestone deposits. Amines react with carbon dioxide to form solid ammonium salt crystals. Trees use up CO2 to make chlorophyll in a process called photosynthesis.

Fact #1. Forests are good carbon sinks. They store carbon in a solid form (trees). But trees themselves are carbon neutral. That is to say, they do NOT actively clean up the atmosphere. Whatever CO2 they use up in photosynthesis, they return to the atmosphere by means of respiration, anaerobic decomposition and forest fires. So, a tree is just about as effective at cooling down the earth as furniture made from it, because both are merely carbon sinks. Human beings too are carbon sinks. A 100 kg man is equivalent to 66 kg of sequestered CO2. So having more human beings on the planet would mean lesser equivalent CO2 in the atmosphere. (But the disadvantages of having more human beings far outweigh the benefits. So let us ignore that option for a while.) Decaying animals and plants emit methane and carbon dioxide, which contribute to global warming. So why don't we seal off dead organic matter in airtight concrete blocks and bury them in the bottom of the ocean where it won't trouble anyone. More carbon sinks.

So the idea is to have less carbon floating about in the air, which means fewer solar rays would be trapped. That would cool down the earth. There are other ways of cooling the earth, too. I was about to suggest attaching huge cooling fins to the earth, but in the interest of practical science, I won't.

Then there is all this hype about having more Green buildings. Though I am not entirely opposed to the idea, I do think that green is a rather tasteless colour for a building. I prefer lighter shades of grey or beige. But then that's just me.

Our problem is not drowning baby seals or submerging coastlines. Those are just the symptoms of the problem. The actual problem is that there is too much water in the world. Again, the extra water wasn't brought by aliens from outer space. Like carbon, it has always been present on the earth for millions of years. But what is worrying is that recently, it has started moving about. That is the real problem. Too much water let loose in the wrong places. That is to say, your real problem is not the children tripping over in the balcony or the foul smell in the house. It is the dead cow in your front yard. So we need to find a place to store the extra water drained by melting glaciers. In other words, where on earth can you hide a large glacier without anyone noticing it? Think... Water tables. There is water at atmospheric pressure under the ground in most places. It is known as the water table. But in deserts and arid regions, the water table is so low that even deep rooted plants cannot reach it. So there you are. Sweep the glaciers elegantly under the carpet. What's more, it fits like a jigsaw. Fill up the desert water tables with desalinated water. Use the melting glaciers to replenish the ground water in arid areas. Use it to make deserts more fertile. Use it to solve the portable water crisis of the third world. We'd have solved the global warming and drinking water crises of the third world in one fell swoop.

Place huge silica gel slabs in the middle of the desert, which soak up humidity from the atmosphere. Or just dip silica gel cubes in the ocean and throw them in the Sahara desert. If you store enough water to compensate for a glacier's melting and flowing into the Atlantic, it would be the algebraic equivalent of depositing a glacier in the middle of the desert. The net sea level therefore remains the same.

Fact #2. Methane is 72 times more effective than CO2 in trapping solar radiation. This means that one litre of methane will have the same effect on global warming as 72 litres of CO2.

A 1.8L petrol engine with a compression ratio of around 10 running at 3000 rpm will emit 90 litres of carbon-dioxide at a temperature of 900C, which is roughly equal to 54 grams of CO2 every minute. A cow releases 500 litres of methane into the atmosphere every day. That is an equivalent of 495 grams of methane at 1013Pa. Since methane is 72 times more effective than CO2 at trapping solar heat, a car would have to run for 660 minutes a day to match a cow. At 3000 rpm that would anywhere between 330 to 935 kilometres a day, depending on the gearing ratio and traffic density. And I am talking about the crudest of internal combustion engines - not the modern DOHC VTEC units with 5 valves per cylinder and twin spark plugs, with catalytic convertors attached to the exhaust - Those would produce even lesser CO2 than a butterfly breathing, and would be embarrassingly inferior to the average water buffalo in terms of greenhouse gas production.

(Are you even paying attention?!)

So, in what way is it fair to ask car owners to pay a green-tax and expect their vehicles to clear a Pollution-Under-Control test, and give tax concessions to farmers and livestock owners? Shouldn't cattle-owners be taxed 72 times more? Shouldn't cows and sheep pass flatulence-under-control tests? It is clear that we are ruled by a government which is more concerned about appearing to be environment-friendly than actually doing something about the climate situation, and doesn't want to lose favour with the large farmer vote-bank. So, we are required to pay taxes on motor vehicles. But if you really think about it, how can you stop a glacier melting by paying money to the government? How can you solve a climate change problem by throwing money at it? It's a bit like trying to stop the phone ringing by screaming at it.

Paying green-tax only makes the government richer. And the only question it will answer is what colour the leather seats in the MP's next premium car should be. It should stop.

Methane is more dangerous than Carbon-dioxide. It also reacts with steam to form methanol, which is a hygroscopic substance. That is to say, it absorbs water. So, methane from cows can be made into methanol, which can be used in place of silica gel in the deserts to soak up the extra water. So there is less methane in the atmosphere, less water in the north seas and more water in the deserts. Three birds with one stone. I am not talking about 2p savings here. I am talking about removing huge chunks off the carbon score-sheet. The kind that will set us back 5 to 10 years in the greenhouse timeline. Polar bears are good. Plastic is bad. Plainly, what we need are genetically engineered polar bears which eat plastic. That ties up the equation perfectly. That's the kind of innovation we want to see.

The problem essentially is that there is a thick layer of carbon-dioxide covering the earth which is trapping the solar radiation. What we really need is a... "hole"... in this carbon-dioxide layer through which heat can escape to outer space.


er....I think we can easily manage to do that. We have accomplished something similar before.

Fact #3. Melting icebergs DO NOT increase sea levels. Icebergs are chunks of ice floating in water. The reason why ice floats in water is because it is less dense than water. One litre of ice weighs less than one litre of water. So, when floating ice melts, its density increases and it occupies lesser volume. Water is densest at 4 degrees above zero. So, the sea levels would decrease as icebergs melt.