245) What can be done to avoid a global disaster?


Ludwik Kowalski (8/2/05)
Department of Mathematical Sciences
Montclair State University, Upper Montclair, NJ, 07043

Discussing energy-related issues (on phys-L, a website for physics teachers) one contributor asked three questions. The replies posted by another teacher (see below) are interesting and worth showing here.


1) By how much would the emission of CO₂ etc. be reduced if 100% of US electricity were from nuclear reactors?

Not likely to happen. Currently we get over 60% of our electricity from coal and about 15% from nuclear. We would need on the order of 300 new nuclear plants to take over the coal burden. It is also the case that our energy demand for electricity is increasing (as a percentage of total energy use) even though the electrical usage is only on the order of 20% of total usage [actual values depend on whether you look at gross or net usage.] Even with the incentives of the new energy plan, it could be 10 years before the first new nuclear plant would be built.

2) By how much would the emission of CO₂ etc. be reduced if 100% of US vehicles were powered from rechargeable electric batteries (using nuclear electricity)?


Not likely because of the lack of progress in battery technology. Fuel cells (run on hydrogen separated by electricity from water) are a possibility, but current prototype vehicles run hundreds of thousands of dollars. There is the whole infra-structure, chicken & egg thing here too--you can't sell hydrogren powered cars (combustion or fuel cell) until there is a wide spread network of hydrogen 'filling stations' and who will build those if there are no hydrogen powered cars to buy the fuel.

3) By how much would the emission of CO₂ etc. be reduced if we used trains and busses instead of automobiles?

The infra-structure cost of mass transit (other than busses) is just too prohibitive to expect to see much happening without some kind of major federal program feeding billions of dollars into such a project. [New urban rail project go for 50-500 million per mile.] Getting people to ride busses is not going to be easy either. However, one CAN reduce gasoline usage by 30-40% just through car-pooling [70% of our driving is done commuting to work]. Agressive programs could do a lot with this without any infrastructure costs. However, there will be GREAT opposition to any reduction in 'driving freedoms.' We've built an entire culture (and a large chunk of our economy) based on the automobile, and moving away from such will be very difficult and disruptive to the economy (short term at least).

Conclusions:
For actual numbers the web. <http://www.eia.doe.gov/> is the place to find all the information you would need. The bottom line to all of this is that there won't be any quick and drastic cuts in CO₂ emmissions from the U.S. or from the world for that matter. Weaning our energy systems off of the fossile fuels (currently 90% of supply) will take 50 year at best and more likely will take most of this Century to accomplish. However, it is by no means certain that we can actually totally replace our fossil fuel energy with 'green technologies' and even less certain that we could do this for 9 billion people all living at a 'western' standard of living. There are money, land usage, and materials problems with scaling up any of the current 'clean' energy technologies to really take over from coal, oil, and natural gas. . . .

Try one of my newer Energy Management Simulators to get a feel for the problem--see web site below.


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R.W.Tarara
Professor of Physics
Saint Mary's College
Notre Dame, Indiana

Free Physics Instructional Software
Windows & Mac

New Energy Management Simulation software just posted.

www.saintmarys.edu/~rtarara/software.html
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