Thread by @AlexWodak

From Emeritus Professor Zelman Warhaft, Cornell University: @simonahac
“Global warming is caused primarily by adding Carbon dioxide (CO2) to the atmosphere from the burning of fossil fuels. The lifetime of the carbon dioxide we emit into the atmosphere is long: ..
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.. in the range of many hundreds of years. And about a quarter of the carbon dioxide we are emitting will remain in the atmosphere for tens of thousands of years: essentially forever. Every time we turn on a light (if our power comes from fossil fuels) we need to think ..
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.. we are emitting stuff into the atmosphere that in effect has the same lifetime as radio active waste. If we were to become completely carbon free tomorrow (using only wind, solar , hydro (and may I mention this word!),nuclear, …) we would not begin to ..
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.. see a reduction in atmospheric CO2 for at least a century or two. This is horrifying and not many people know it.
At present, the world population is around 7.5 billion. On average every person uses around 2 kW (Kilowatts) of power. This is as if everyone in the world ..
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..(power wise) is equivalent to two electric heaters running continuously—twentyfour-seven. Of course in many parts of Africa etc. it much much lower and in the U.S it s close to 10 kW per person. Multiply the two numbers together and you get 2 kW per person x ..
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.. 7.5 billion people = 15 Tera Watt (TW). (15 with 12 zero’s). An enormous number (very small numbers multiplied by extremely large ones produce produce enormous ones!)
At present over 80% of the world’s power is from fossil fuels. This number hasn’t budged much for the ..
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.. past 50 years. And of the remaining 20% most is traditional energy (biomass, hydro..). Only a few percent is from solar and wind.
By the end of the century we expect a world population of around 11 billion. If we want the poor countries to have anything like a ..
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.. decent way of life, let us assume on average the per capita power usage increases from 2 kW to 4 KW. Thus we might expect, in a reasonable world, a total power consumption of 4 kW/person x 11 billion people = 44 TW by the end of the century. This is 3 times the power ..
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.. we are now using. We need to cater for this massive increase in power usage. And it all has to be fossil free. (44 Tw is equivalent to 44 thousand nuclear power plants (there are 400 now) or 10 million very the largest wind turbines.).
The cost of carbon free power ..
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.. is a few dollars per watt. So changing over completely will cost in the order of tens of Tera dollars (10 with 12 zero’s). i.e. many tens of trillions of dollars (1 Tera= 1 trillion). I noticed recently a U.N. funding agency has pledged $1 billion in new investments ..
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..to help poor counties tackle climate change. Like treating cancer with an aspirin. But the cost will be much greater than this since we will need new power transmission infrastructure, storage etc. You might say that we are continually updating our power generation plants
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.. Yes, but the change over to non fossil fuel power needs to be done with extreme urgency. We cannot let existing coal, natural gas plants etc. run their course. (We are bringing on new gas (and coal) plants as I write). All new power generation needs to be ..
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.. non fossil and we cannot retrofit exiting fossil fuel plants (unless we use carbon capture, see below). And I have not mentioned the new infra structure needed for transport, agriculture etc. (There is little to be gained in running electric vehicles on electricity ..
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.. generated by fossil fuels).
A recent IPCC (Intergovernmental Panel on Climate Change) paper talks about a world with an elevated temperature of 1.5 C (from the pre-industrial revolution level). We are now more than 1 C. The Paris agreement (2015, when things
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.. looked a bit rosier than now), aimed at 2 C or less. I think, along with many others, that between 3 and 4 C is more realistic.
There will be mass suffering. Unfortunately we have been there. This century does not look as if it will fare any better than the ..
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.. previous one with perhaps 100 million dying because of wars, disease and starvation. We are seeing a bit in Lesbos and other refugee camps, and in the floods and fires caused by global warming.
Some will say my pessimism is playing into the hands of the ..
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.. reactionaries, oil companies, etc. They too have done this arithmetic and see that it is more or less impossible to avoid (and so they don’t worry and enjoy their profits).
Others say we should act optimistically and aim for 2 C or less warming.
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.. I think this is dishonest. I think now is the time to press home the shocking truth. And of course to provide guidance. The situation is dire but not completely hopeless: The cost of dealing with global warming could have worked out be many times the world GDP.
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.. This would be a truly hopeless situation. While the cost of addressing climate change is in the 10’s of trillions of dollars, this is only a small part of the world GDP (80 trillion $). But to echo the chorus, we must start in earnest right now with mitigation and
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.. conservation. Most importantly we need to start adaptation immediately (flood walls, adaptive crops etc.), on a massive scale. We will also have to suck some of the existing carbon dioxide from the atmosphere. Research is being done but it is still unclear
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.. whether this is feasible on the scale that is needed. The cost of this will be enormous. We are adding around 40 billion tonnes of carbon dioxide to the atmosphere each year (around a tonne of carbon per person per year). At a reasonably conservative guess
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.. (no one knows) of $30 per tonne, this would be over a trillion dollars a year for sequestration. Even with all of this, it still will be a difficult path, with much suffering.
Many argue that we are doing too little too late to avoid the worst
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.. consequences of global warming. Should we have acted in the 1950’s when the first measurements began to show how deep the problem is? There was little likelihood of enacting massive changes in our energy infra-structure at that time. The recovery from World War 2
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.. was ongoing in Europe; there was one of the most-costly arms races in history between the Soviet Union and the U.S.; third world countries were so impoverished that the notion of involving them in a venture to change their energy structure would have been seen as absurd.
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.. Yet to avoid global warming, we would have needed to start very early indeed. Certainly by the late 1980’s the die had been cast.
We often assume personal or collective guilt for the situation we are in. Or we blame the oil and coal industries for seducing us.
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