Okay, so it's not Carbon Dioxide Appreciation Day, but it should be. It is the atmospheric CO2 that our green plants love so much. If plants could talk, they'd take us to task for trying to reduce carbon dioxide emissions. An added irony is that we're talking about CO2 reductions - ostensibly because increased CO2 is supposedly adding to the greenhouse effect which is supposedly increasing the Earth's temperature - yet since 1998 the Earth's average temperature has actually dropped, and solar scientists are predicting a continued downward trend in Earth's average temperature due to decreased solar activity!

Ummmm......if we're heading for another Little Ice Age, shouldn't we be increasing CO2 to help offset global temperature reductions?

An interesting point about steam vs diesel locomotives was made in another rail forum. Although classic coal-fired steam produced relatively dirty exhaust compared to the new diesels, today with modern coal-firing technologies a modern coal-burning steam engine would actually be cleaner than today's modern diesel locomotives in all emissions except CO2. The reason for this is due to modern particulate-capture technology as now employed at coal burning power plants, and the introduction of the fluidized bed concept. And yet, even with modern technologies and low sulfer diesel fuel, emissions of real pollutants like SOX, NOX, and particulates from compression-ignition engines is higher than those from coal-fired power plants. This is one pollution-related drawback of the internal combustion engine when compared to the external combustion engine.

Just something to ponder on this CO2 Appre......errrr, Earth Day (gag!)