earth history

I've been very remiss not to post for so long, and so much has been happening it's hard to know where to start, so you might think my choice is a bit strange. It's this article from Foxnews on the end of life of our good planet. The take-home point is that our planet might not be liveable all the way until the end of life of the Sun. This is because the Sun's heat slowly increases. From being maybe 30% cooler when the Sun first formed, it will end up maybe 30% hotter than it is now. This will mean the Earth will pass from the 'habitable zone' into the torrid zone, the oceans slowly evaporate, the Earth's natural thermostat fails, and the planet suffers runaway heating until all life is gone.

To give you the flavour of it, here is a short clip from the article:

Earth could continue to host life for at least another 1.75 billion years, as long as nuclear holocaust, an errant asteroid or some other disaster doesn't intervene, a new study calculates.

But even without such dramatic doomsday scenarios, astronomical forces will eventually render the planet uninhabitable. Somewhere between 1.75 billion and 3.25 billion years from now, Earth will travel out of the solar system's habitable zone and into the "hot zone," new research indicates.

Very interesting. The only problem is this is old, very old, news. In the "Tree of Life" book Gitie and I wrote in 2003 we discussed this very problem.

As readers will know, I have been thinking about the hullabaloo about CO2 and global warming and I quickly concluded that CO2 is no threat, won't do any significant warming (which would be good anyway), and is in fact 100% good for the planet. But someone said to me, if CO2 is no danger, that doesn't mean that humans are not causing a danger in some other way. Of course I agreed with this, because there are lots of things humans are doing wrongly and thereby causing terrible damage to our world (and the CO2 storm in a teacup is distracting us all from fixing those real problems).

My friend then went on, however, to propose that the danger was still global warming and that the mechanism was, instead of CO2 greenhouse warming, the mere fact that human technology gives off heat. All the power used by all the machines and transport and so on eventually ends up as waste heat. Maybe that is in itself enough to cause us serious warming trouble? So I did some calculations.

According to the laws of thermodynamics, the process of doing useful work must necessarily lose some of the energy from the fuel in the form of waste heat; and that heat, well, heats. In other words, because of the huge extra amount of useful work we do, we create excess heat that would not have been here otherwise, and that heat has to either be dissipated somehow, or else raise the temperature.

The factors that have caused the ice ages, as we saw, are primarily small changes in insolation (heating) by the Sun. The changes can happen because the Sun’s energy output changes or because of cyclic changes in the Earth’s orbit and inclination, etc., changing the amount of heat that actually arrives on the surface. Changes in the Earth’s orbit are believed to be the triggers for the onset of ice ages, and the changes in heating caused by those changes are thought to be quite small compared to the total power output of the Sun. This might lead us to suspect that human-caused changes in the amount of heat at the surface might indeed have a significant effect on the climate.

This is a reasonably short work, very different from Ian Plimer's Heaven and Earth. Although Paltridge is an atmospheric physicist and erstwhile Chief Research Scientist with Australia's CSIRO, he has put together an accessible summary of some of the damning evidence against the global warming alarmism.

I'll probably be posting quite a bit about global warming, and you might wonder why I think it's a big issue for a site devoted to peace. Well, peace is easier if we aren't all scrapping with each other to eke out an existence in a starving world. True peace (which includes peace with all our nonhuman friends) requires we don't do things that will harm wildlife or damage Earth's capacity to feed us all. True peace should make everyone happy; and if you've seen Gitie's and my wild bird website (wingedhearts.org, you'll know I don't reserve "everyone" just for people.

Four and a half billion years... half way through the lifetime of a planet... for some of that time molten and dead from bombardment in the early formation of the solar system... for most of the remainder inhabited only by single-celled life forms. And for a 'mere' half billion years, a flourishing of plants and animals. Then at last, for the merest flicker of geological time, there are human beings. How very long it took until a tool-making, syntactic language-using, self-reflecting species arose—for the first time and (for all we know) the only time in the entire galaxy.

But life on Earth is dangerous. Mass extinctions can happen slowly through geological changes that cause vulcanism and planetary cooling, or quickly through a collision with a meteorite. A nearby star could become a supernova. At least twice in its long lifetime, Earth has been frozen solid or nearly solid all the way to the equator—the sort of ice age which, if it happened now, would exterminate all multicellular life. Bacteria would once again be the only life forms. By the greatest of good fortune, our planet has survived until it is within reach of safety from cosmic disasters: its latest creation, ourselves, is slowly maturing in its capacity to develop the means to safeguard the planet for all life.