At 02:35 5/12/2007, you wrote: > > There is "Climate Change", there always has been "Climate Change". > > there was an Ice Age and the earth is going through a warming cycle > > that has been going on since the last Ice Age. (Geoff, as > recently as 1982 scientists thought we were heading for a new ice > age caused by global cooling!) > >..... and the Earth continues to warm up (by insolation)... > >..... until it is hit by a big meteor which throws dirt into the air blocking >insolation and causing cooling (as in the last ice age). This wipes out >many species.
Not that simple, even for a neonatologist. But there is one simple concept nobody has raised here yet (or in the popular science debates). That was the old paradigm. Left to its own devices, the earth stays in rough balance by radiating out the energy it receives. However, (1) it takes time to achieve equlibrium; (2) the rate of radiation is less if there is more cloud or more greenhouse gases to trap the heat by re-reflecting it back to earth; (3) the rate of sunlight (energy) getting in depends on the amount of cloud reflecting it back and the amount of particulates stopping the sunlight getting to the surface and heating the atmosphere. HOWEVER, this assumes that no extra heat (energy) is released at the surface. It is patently obvious that humans are now using energy at such a rate as to affect the overall balance, and all energy eventually defaults to heat - hence the earth's surface warms as the waste product energy accumulates until it can be re-radiated to space as long-wave radiation. Unlike other historical events, we cannot tell yet if that effect is self-correcting. The only way to radiate more energy (as a very rough approximation to a black-body radiator) is to radiate it from a hotter source - hence the planet MUST warm up if it is to radiate the excess energy being generated at the surface. If we suspect that this is an undesirable situation, we must STOP RELEASING SO MUCH ENERGY. Ideally we will do this by being more efficient and not wasting it, but the fact remains that in the end it will raise the temperature ON AVERAGE. This is where Australia, as a amall buttechnologically smart country, can help significantly BY REDUCING WASTING ENERGY AND MAKING THE TECHNOLOGY AVAILABLE TO ALL. In the long term, we must also reduce the global human population if we are to reduce the number of sources of waste. Risk managers consider number of fatalities against frequency to decide if a risk is unacceptable - a single cause killing 1000 people at the same time is not tolerable more than once in about 10 years. By extrapolation, killing 5 billion people once in 5 billion years is also intolerable - so half the planet's population being killed by a nearby star going supernova once in the current age of the universe is intolerable. The only factor we have any control over (apart from rewriting what probability we accept) is to reduce the global population! (not in the way one loony candidate party at the recent election has proposed, either - by a solution akin to myxo or calici virus for rabbit control, or relying on war and famine as we did in past generations). The problem goes deeper than just greenhouse gas emissions - it is ENERGY USAGE at a rate beyond our capacity to maintain the environment in a range where we KNOW FOR SURE that we can survive it, and which probably takes us outside the range of geological history caused by variations in solar output in any time-scale we can reliably infer from the up-front evidence. CO2 is only a minor part of the overall equation, but it is the political flavour of the year. Wombat _______________________________________________ Aus-soaring mailing list [email protected] To check or change subscription details, visit: http://lists.internode.on.net/mailman/listinfo/aus-soaring
