The coal doesn't do anything about the rotation of the earth. That dam in China, the Three Gorges one, does, but it is not enought to actually effect anything, as it is like a 10th of a milimeter or something for the rotation of the earth.
Coal is extremely damaging to Earth's atmosphere, however. When coal is burned, it puts out CO2, which is a greenhouse gas, and traps heat in the atmosphere, causing global warming. Global warming already contributed to the severity of Katrina (but not to it's existence). Global warming is the single most serious threat to man kind and many species of animals (although mosquitos want global warming, as they will multiply many times over in a warmer climate).
The biggest threat is sea level rise, which is predicted to be 3-10 feet in the next century, and more beyond that. Humans need to stop burning fossil fuels like coal and oil, and switch to renewable green energy to reduce our CO2 output 80% from year 2000 levels by 2050 if we want to avoid disaster worldwide. Global warming has already caused droughts and storms in other parts of the world, and third world countries are much more seceptible to damage than first world ones.
If you want to learn more about global warming, get Al Gore's An Inconveient Truth. Whether or not you like Gore, it is a great, scientifically mostly accurate movie about the threats of global warming. He does, however, use the highest sea level rise predictions of 20 feet, which are unlikely to happen in this century. If you find websites or articles that are skeptical about humans' impact on global warming, trace their funding, you can usually trace it to a "think tank" that is mostly funded by US coal mining interests or Exon-Mobil. They want to pollute, and they want to keep doing it unchecked.
Some players in the US power industry see the problem. The CEO of Xcel energy is quoted as saying about reducing CO2 emissions, "give us a target, and we will meet it", in reference to governmental regulation of CO2 emissions. They have already converted coal power plants to cleaner burning natural gas, which is a stopgap measure, but still progress in the right direction.
The government's (Bush's) irresposible leadership in reducing US CO2 emissions, which are 30% of the world's CO2 emissions with 5% of the population has also screwed up the power grid. Companies can't justify spending $100M+ on a new multi-GW coal power plant, as if the government starts acting responsibly, and regulates CO2 emissions, the plant would have to be shut down before it recoups even part of its cost, along with many older plants, but if they build a highly efficient dual cycle supercritical coal gasification plant with CCS (carbon capture and storage, a technology to shove a pure CO2 stream from coal gasification deep in the ground, where it stays pretty much forever), or newer, reneable energy sources like solar (with steam generators, not PV solar), or wind, they won't be able to compete in the power market that is run largely by older, atmosphereically vented coal and natural gas plants.
Thus, power companies aren't investing in anything, and the number of nuclear plants has gone down, as well as some older oil plants have disappeared, at the same time as power consumption has gone up. That is not a good thing for the grid.
The US needs to lead in investing in new, renewable technologies, and help other countries, like China, to stop increasing their CO2 emissions. In fact, China is building coal power plants every week, increasing CO2 emissions rapidly. If the US takes the lead with renewables, we can create a huge number of jobs, and the worldwide market for renewable energy can be huge, like hundreds of billions of dollars.
The other side of the equation is the cars. Cars use a lot of gas, which also puts out CO2. There are many solutions for cars. The first is increasing fleet fuel economy from 20mpg to 40 or 50 mpg. The next is using ethanol instead of gasoline. All new cars in the US (and worldwide) should be required to run on any mixture of pure ethanol to pure gasoline, offering a gradual conversion, and the ability to use the new environmentally friendly fuel, while using gasoline when ethanol is not available. This feature is not available with the bogus technology hydrogen.
Hybrids can also help, as they are more efficient. In fact, if they are designed to be sporty, they can use the electric motors to have BOTH better economy and better acceleration, unlike the current breed of hybrids which are mostly geared toward economy only.
The next technology, if the power grid is beefed up with renewables, is the plug in car. Either pure electric cars or plug in hybrids are both more efficient than current cars. Plug in hybrids use electricity to get about 100mpg, which EV's use electicity only, although they can be outfitted with a ~100hp generator, so that they can go on long trips. They would drastically outperform a gas car, as the batteries can kick out like 400hp for a few seconds to accelerate, and then go back to 40hp for sustained driving, and recapture energy while braking. All of these are also solutions for reducing foreign oil consumption.
So how do trains fit it in? Trains use 1/3rd the energy, and thus 1/3rd the CO2 per mile ton of freight, and they stop highway congestion, so they are part of the solution. They are also part of the problem, as they are the enablers for the big coal polluters. They are also part of the solution, making ethanol possible, without expensive pipelines. They are also part of the solution to reduce car use with communter trains.
Lastly what can you do to reduce your carbon footprint? The simplest is to reduce your energy consumption. This also has the pleasant side-effect of saving money, so you have more to spend on your trains.
The easiest way to reduce your carbon footprint is to use more efficient technologies to do the same job with less energy.
The first, and most money saving is compact flourescent light bulbs. They use 75% less energy, run cooler, and they last 10X as long as incadescent models. I have about 85 of them, they are great. Flourescent tubes are also great for garages, basements, and workshops. Replacing all the bulbs in your house is easy, as Wal-Mart stocks a zillion of them. They pay for themselves and start saving $$$ in a few months to two years, depending on how much you use the lights.
Next is heating and cooling. Make sure your furnace is well maintained, and hire a contractor if nececary to insulate and check all of your ducting or other heating equipment to make sure there are no leaks. Also, attics could usually benefit from some more insulation. When you use heating or cooling, don't overdo it. 60ish is fine for heating, and if you really need AC, 75-78 is usually sufficient. If you are hot, try a fan, not the AC. It actually works better with less energy.
As far as electronics, don't run computers when you don't need them, and if you forget to turn them off, set them to go to sleep after 10 minutes. When you buy a new one, make sure it is energy efficient. Apple computers are very efficient, and have good sleep modes. Many Windows laptops are also efficient (and convenient and portable to the train roon
). Many Windows desktops are energy hogs. If you use one, just turn it off when you are not using it. VCRs or other stuff that isn't used often should be unplugged, or turned off with a power strip, as these are "vampires" that just suck juice all the time. The same is true for cell phone and battery chargers, or any sort of wall wart (including your DCC gear). Use them when you need them, but don't just leave them plugged in. This also helps if there is a big surge.
The next time you buy a car, make sure it gets at least 40mpg, 60mpg is even better. Hybrids are great, there are a few electric cars coming on the market in the next few years (~150-200mpg equivalent in both cost and CO2 output). If you have a predicatable and boring communte, one of these is just the ticket, although you will probably still want a hybrid for longer family trips. Plug in cars are much cheaper to operate, and with a pure EV, you never have to go to the gas station!
As with energy, whether in the home or on the road, try to drive less, and use less energy. Turn things off if you aren't using them, etc.
Also, when you buy stuff, try to avoid buying disposable things as much as you can, and try to avoid buying things with superflous packaging, as this all takes energy to make to transport. Meat takes more energy to make than non meat products, so eating less meat helps the earth AND your arteries. Vegetarianism is the extreme of this, but I can't say I have cut back termendously on my own meat consumption or advocate doing so more than a little bit.
Lastly, in some areas, you can buy green energy, they basically charge an extra $.01 per KwH, and offset your energy use by putting green, renewable energy like small scale hydro, landfill gas, or wind, into the grid. There are also carbon offsets, so you can be "carbon neutral" although it is hard to figure out where the money is going, or how it offsets the carbon.
There is lots more information online about saving energy and starting to be part of solution, because just about everyone in the US is part of the problem. Also, urge your Congress Critters (or equivalent for other countries) to do something about global warming. There is also going to be a massive protest called Step It UP 2007! on April 14 to protest Congress's inaction on global warming and push for a plan for an 80% cut in emissions by 2050. There are many websites about global warming and how you can cut your carbon footprint online, and remember, if the site is skeptical about global warming, try to trace the funding back to Exxon-Mobil. Thats usually where it comes from.
EDIT: Spelling
