Ok, so have we been told to conclude that CO2 emissions are not harmful yet?
Question to those who doubt Global Warming: is the quantity of our CO2 emissions harmful or beneficial? If you cannot answer one way or the other, and with proof, then why are you willing to risk the chance that it is harmful? I am not willing to take that chance; I don't care about the street you live on but I do care about my street. Perhaps you are just antagonists getting a kick out of being belligerant.
Let's try this again, slowly:
In the real world, we respond (or should respond) to a perceived risk with a response measured against that risk. I already gave an example in a previous post: we KNOW that asteroids and comets have struck the earth in the past and will again. If a single asteroid measuring two or three miles across hits us, we will be wiped out in a matter of weeks. We may have relatively little warning, maybe weeks or months if that. Thus, the case can be made that we should develop technology now to divert to destroy asteroids of this size or greater. But at what cost? Are you willing to spend a billion, a trillion, ten trillion for such technology? Are you willing to divert, say, all cancer research funds into giant laser beam technology for such use? No, because the risk is small. Remember: it isn't the outcome only that matters (total global annihilation), but the temporal likelihood of that outcome. People enter into commercial planes all the time, even though the POTENTIAL risk of doing so is to be burned alive horribly in a crash. We do so because the actual temporal risk is minute, less than one death per one million flight segments.
The simple platitude "if you don't know if it's harmful, then we should act anyway" is so ludicrous as to be beyond comprehension. I could ask you: why haven't you built a 250,000 dollar steel canopy over your house? Don't you know that houses have been destroyed by ice falling from aircraft and meteorites? You can't possibly KNOW that your house won't be leveled by toilet ice from a 737, so your failure to act to prevent this must be condemned! The simple truth is, we trade risk for cash or lifestyle on a daily basis. We drive cars because we need to, we dive because we like to, it's all a matter of balance.
We aren't going to spend 200,000 dollars to protect a 100,000 property from a one in a million chance of destruction. That would be stupid. True risk/benefit analysis of a course of action requires complex and detailed knowledge of the costs, risks, and benefits involved. NONE of that is available here. Even if some GW is a certainty, I see no one venturing a intelligent qunatitative guess as to the property or economic damage that will occur (or how it might be OFFSET by benefits of warming, like reduced winter fuel use, better agriculture in certain areas, and so on). I see no guessimates of how much it will cost to reduce the earth's temperature by a certain amount. All I hear is: we're doomed, open your checkbook, the carbon taxes are coming...
To have the correct response to GW, if it exists, we must know the precise risk of GW balanced against the cost of stopping it versus the cost of dealing with it. For example, say GW by 2050 will hurt crop production by x dollars, harm coastal property by y dollars, and so on, if left unchecked. If it costs 10 times more money and effort to stop a certain degree of GW than it would to deal with the potential damage such warming might do, it's best just to let it happen and deal with the consequences.
When the space shuttle was built, the cost planning included a total vehicle loss of one per 100 launches. To make the vehicle safer would cost far more than simply absorbing the economic and political fallout of one shuttle disaster every decade or so. That's the way the world works. We can't eliminate every risk or prevent every bad outcome, particularly if, in doing so, we incur more injury eliminating the risk that the risk itself might ever cause. A warmer climate might, in the end, cost us less grief ---economically, culturally, socially --- than trying to slam the brakes on our current way of life. But why do I worry...that isn't going to happen and we all know it.
I hear that this ice cap is melting, blah, blah, blah. The best I can extract from the UN report is, in worst case scenario, the oceans rise 39 inches by 2100 and the temp goes up by several degrees. Is such a slow rise of the sea level or air temp really going to produce such havoc that we must spend any amount of our resources to stop it? Is this rise going to harm coastal economies more than, say, beach erosion and weather already affect it. Won't we slowly adapt to such gradual changes as they occur? Why the "sky is falling" atttitude? Will driving fuel efficient cars or using curly light bulbs across the globe really impact this slow trend to a degree that offsets the increased costs of such technologies?
I see only one reason for the "act now" approach: grab the handles of power while people still believe this bunk. Fads have a short half-life and I suspect this one is already going the way of the bird flu. Hence the strident, panicked tone of GW advocates.