I don't think that it really matters if Global Warming exists or not. The truth is that many humans, not just Americans, are wasteful and have been for years. Whether the earth is simply going through another era of temperature change or if we caused it takes away from the debate of what an individual can do to be frugal with our resources.
As far as government trying to force people to be environmentally friendly, etc., I think that that does more harm than good. People, especially Americans, do not like theories being forced down their throats. A more pragmatic approach to getting people to conserve is to focus on the positive. I know that I tend to be turned off by scare tactics because politicians use them so often without any logical support. So, if we want to encourage people to lessen pollution or use resources wisely, we should offer methods that will save money (because everyone likes that!) and that are relatively simple to enact.
The previous posts have done a great job in articulating the need for action at this time on the environment. I do believe that there is a natural tendency for the earth to go through temperature change cycles. However, I believe that the human controlled elements have impacted climate change, contributing to global warming. The real challenge for the remedying of this predicament will be to see if individuals are able to follow through on their commitment to environmental awareness even if it causes some level of inconvenience.
The Global Warming "skeptics" have been getting alot of press lately, due in large part to the fact that they are well funded and their main strategy is to raise doubt in the public mind.
That said, I don't think there's any question that we don't know FOR CERTAIN what the future holds or what/who is to blame. However, there is more than enough evidence that human activity may well be causing a catastrophic situation to warrant major efforts on our part to reduce CO2 and other greenhouse gasses in the atmosphere. If we're wrong, ok -- we may have taken some unnecessary steps. If we DON'T act and we're wrong, we're in deep trouble.
In the political world, one of the main points of debate seems to be whether or not human beings are responsible for global warming. The conservatives I've heard tend to embrace one of two opinions--that global warming isn't actually occurring at a pace which should be alarming, or if it is, it's not really anything that human beings are doing that is causing it. The liberal side is considerably more alarmist, and tends to think that global warming is occurring at a rate that could create catastrophe in the too-close-to-be-comfortable-future, and that it is largely attributable to human activity. There is enough scientific evidence from a enough sources to point to a warming trend in the earth which could be problematic in the future if not curbed, and if it is a trend that could prove to be dangerous, then it really doesn't matter who or what is actually causing it. If human beings are causing it, then there are certainly plenty of changes we can and should make to minimize the warming trend. If human beings are not the reason for global warming, then that's almost a bigger problem, because that means something is happening that is likely beyond our control, and we should do everything we can not to make the problem bigger than necessary. In short, there is no excuse in the United States at least, to be unaware of how to live a greener lifestyle; if each person made just one or two small changes in his or her lifestyle, the impact would be tremendous. Why conservatives or anyone else would object to making a few small lifestyle changes that certainly won't increase global warming, and probably will help slow it down is beyond me.
THERE IS NO GLOBAL WARMING!!!.
It's estimated that the Earth's surface would be about -18 °C with atmosphere and clouds but without the greenhouse effect and that the (we'll call it "natural") greenhouse effect raises the Earth's temperature by ~33 °C.
We should note that devoid of atmosphere Earth would actually be a less-cold -1 °C while ignoring that clouds add significantly to the greenhouse effect.
Theoretically, if the planet's surface cooled by radiation alone, then the greenhouse-induced surface temperature would be much warmer, about 350 K. Atmospheric motion (convective towers carrying latent and sensible heat upwards and large scale circulation carrying it both upwards and polewards) circumvent much of the greenhouse effect and significantly increase the "escape" of energy to space, leaving Earth's surface more than 60°C cooler than a static atmosphere would do.
Despite there being far more greenhouse gas in the atmosphere than required to achieve the current greenhouse effect, something which has been true since before humans discovered fire, evapo-transpiration and thermals transport heat higher in the atmosphere where radiation to space is increased. This is why Earth remains about 15°C rather than about 77°C .
There is enough evidence to establish without any doubt that global warming is occurring at an alarming rate and that it is caused by human activity. People who think otherwise ans suggest the we need not worry too much about it, remind me of the French Queen during the French Revolution, who once asked why people are agitating, and when told that they have no bread to eat, suggested that "they should then eat cakes".
Among the knowledgeable people the debate is not about the seriousness of the global warming problem or its causes. The main controversy is about who should take how much responsibility and act for controlling global warming. IN this debate the whole world can be roughly divided in two groups - the highly industrialized rich nations and not so developed nations. The global warming so far can be linked primarily to the development of the developed nations. As a result, the polluting CO2, which is the primary cause of global warming, emitted by developed countries in terms of per capita emission is several times more than that by other countries. Now, as the less developed countries try to catch up with the prosperity levels of developed countries, it does add to the global warming question.
In this situation, is it justified for developed countries to expect that developing countries should limit further increase in levels of CO2 emission even if it seriously hampers their progress towards a better life, while they themselves continue to pollute the globe at several times higher rate. In some other places I have seen posts where people talk about buying more fuel efficient, and at the time more expensive, cars to save fuels. But what about the person who is so poor that he cannot afford to by a bicycle? Should he be prevented from using even a 50 c.c. motorcycle because that will increase the level of environmental pollution.