under estimating kongming

Part 5 - Dr Lee Zhang has disappeared

It was unseasonably warm over the weekend and a lot of snow had melted by Monday leaving odd patches of ice on the side walks.

Toxic McTavish was a slim, middle-aged teacher, so named for her constant warnings that whatever chemical concoctions, we came up with, were probably toxic. But, instead of the usual chemistry lesson we got a rant about climate change. She had read the book, Life's Engines: How Microbes Made Earth Habitable by Paul G. Falkowski, and urged that we all read it. I made a few notes as she wrote comments on the blackboard.

Three billion years ago, the Earth's atmosphere consisted mostly of nitrogen and carbon dioxide, both inert gases. There was little oxygen. But then microbes began using sunlight as a power source to extract carbon from the carbon dioxide to create more life forms. Oxygen, a highly reactive waste product, was dumped into the environment. So the atmosphere gradually changed from one with very little oxygen to one with very little carbon dioxide (currently about 0.04%, or 400 parts per million by volume).

Some organisms began to obtain carbon by eating other organisms and using oxygen (instead of sunlight) as a power source. The waste product, carbon dioxide, was re-used by microbes and plants so it did not accumulate in the atmosphere.

When organisms died, the carbon was released but some of it was buried in the earth's crust, often combined with hydrogen in the form of gases like methane.

Carbon dioxide is produced by all air breathing organisms, volcanoes, decaying organic matter and forest fires and also by internal combustion engines and many electricity generating stations. Thus, carbon and oxygen are combined and re-separated in an continuous cycle.

Today there is some evidence that burning buried carbon (in the form of coal, gas and oil) will increase the amount of carbon dioxide in the atmosphere which will cause the planet to warm up, as carbon dioxide tends to trap the heat provided by solar radiation. There are estimates that the amount of carbon dioxide in the atmosphere has increased from about 0.028 % at the start of the Industrial Revolution (about 200 years ago) to the current 0.04% an increase of about 40%.

There are three objections to this theory. From the beginning the sun, meteors and volcanoes have caused changes in the planet's climate. Often huge changes. A mere 18000 years ago, about the time North America's first human immigrants arrived, both polar areas were covered with ice caps much larger than the current ice caps. The Ottawa valley, for example, was buried under two kilometres of ice.

About 70% of the earth's surface is covered with water which makes it resilient to temperature fluctuations. Water can absorb a lot of thermal energy and, when heated by the sun, it evaporates (a process that also absorbs a lot of energy) and the vapour rises in the atmosphere until it condenses to form clouds which are very good at reflecting the sun's radiation back into space. Also, the warmer air spills toward the cooler polar areas (which are at an angle to the sun's radiation so that the energy per square metre is less than that at the equator). The oceans also transfer solar heat by currents. The Gulf Stream delivers a current of warm water from the Gulf of Mexico which keeps Iceland and northern Europe much warmer than they would be without the Atlantic ocean.'

Plants are continuously extracting carbon dioxide from the atmosphere. If there is more carbon dioxide there will be more plant life. Ontario farmers pump carbon dioxide gas into their greenhouses to increase the productivity of their tomato plants. And plants absorb radiation which tends to cool the planet.'

Conclusion: It is probably unwise to extract the carbon from the Earth's crust within a short time but it may be an enormous waste of wealth to stop using carbon fuels before there is unequivocal evidence that it will cause catastrophic climate change that cannot be ameliorated by less expensive methods.

Finally, Toxic set our homework. One page explaining whether we should be building nuclear power stations or windmills.

After school hours, I worked on the homework in the school library. Eventually, I had to go to the washroom. On the way, I found Dr Zhang's office door wide open. Someone had broken the lock.

I froze, listening for any noise. Nothing, except the rattle of a cleaner's bucket in the gym. I crept slowly to the office and peered cautiously around the edge of the doorway. Dr Zhang's parka was still draped over his chair. The office looked undisturbed but Oppy was running. I thought Dr Zhang had shut her down after the last disaster, when we had ended up in Britain.

I checked the machine shop but Denny wasn't there so I ran back to the office and called Denny's apartment using Dr Zhang's phone. He didn't answer so I left a message, telling him to call Licia's home number, and then I called Licia and Miguel.

Miguel and I were at Licia's place, fifteen minutes later, when Denny called.

'Hi, Denny,' I said. 'Sorry to disturb you. This is Ziff. Can you meet us at Dr Zhang's office. We just had a B and E.'

'Did you say breaking and entering?' There was a long silence. 'Blimey . . . I'll be there in twenty minutes.'

We got to Dr Zhang's office first and looked around. Miguel opened a cupboard and peered inside.

Oppy's monitor lit up immediately. 'If you are looking for fortune cookies, they are in the top cupboard.'

'I am not accepting any interruptions until further notice, or until someone apologises for saying I am unreliable, whichever comes first.'

Denny arrived, looking worried. He made a cursory check, before deciding that nothing was missing or damaged except the door. I asked where Dr Zhang was and he looked at me in silence for several seconds.

'Guys,' he started uncertainly, 'Lee Zhang has disappeared through the blooming electric bookcase. I think accidentally, because he didn't tell me he was off to China. I am working with Oppy from home, to find out what happened, and I must get back to work. I'll let you know as soon as I find out what happened.'

A few minutes later, we were sitting in Licia's basement, sipping hot chocolate and discussing recent events.

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