Neither too close nor too far from the Sun.
Towards the end of the lecture that Lord Martin Rees gave at University of Melbourne’s Medical School in 2010, he spoke of the way that Planet Earth has warmed up these last 100 years, warmed up uniquely. Why the word ‘uniquely’? Because, for the first time in the ancient life of our planet, that warming is the result of the activity of a life species living on that planet; mankind. It’s difficult to comprehend how special, how fragile and, therefore, how vulnerable is mankind’s ability to survive on Planet Earth. That’s why a recent item on Martin Lack’s excellent blogsite Lack of Environment is published on Learning from Dogs with Martin’s kind permission. But first let me quote a little from WikiPedia about the ‘goldilocks principle’,
In astronomy and astrobiology, the habitable zone is the region around a star where a planet with sufficient atmospheric pressure can maintain liquid water on its surface.1 Since liquid water is essential for all known forms of life, planets in this zone are considered the most promising sites to host extraterrestrial life. The terms “ecosphere” and “Liquid Water Belt” were introduced by Hubertus Strughold and Harlow Shapley respectively in 1953. Contemporary alternatives include “HZ”, “life zone”, and “Goldilocks Zone.”
“Habitable zone” is sometimes used more generally to denote various regions that are considered favorable to life in some way. One prominent example is the Galactic habitable zone’ (the distance from the galactic centre). Such concepts areinferred from the empirical study of conditions favorable for life on Earth. If different kinds of habitable zones are considered, their intersection is the region considered most likely to contain life.
The location of planets and natural satellites (moons) within its parent’s star’s habitable zone (and a near circular orbit) is but one of many criteria for planetary habitability and it is theoretically possible for habitable planets to exist outside the habitable zone. The term “Goldilocks planet” is used for any planet that is located within the CHZ although when used in the context of planetary habitability the term implies terrestrial planets with conditions roughly comparable to those of the Earth(i.e. an Earth analog). The name originates from the story of Goldilocks and the Three Bears, in which a little girl chooses from sets of three items, ignoring the ones that are too extreme (large or small, hot or cold, etc.), and settling on the one in the middle, which is “just right”. Likewise, a planet following this Goldilocks Principle is one that is neither too close nor too far from a star to rule out liquid water on its surface. While only about a dozen planets have been confirmed in the habitable zone, the Kepler spacecraft has identified a further 54 candidates and current estimates indicate that there are “at least 500 million” such planets in the Milky Way.
So now to Martin Lack’s post.
Goodbye Goldilocks Planet?
Is it time to say goodbye to the Goldilocks Planet?
I hope not, because the next-nearest one yet discovered is 600 light years away! However, if we are indeed now passing a tipping point (i.e. as the widespread rapid thawing of Siberian permafrost suggests) both mitigation and adaptation will be almost impossible. Therefore, if we cannot reverse the damage already done (i.e. how can we make permafrost re-freeze or reverse the retreat of mountain glaciers?), we may have to accept that temperatures will eventually rise to a level at which the Antarctic first became glaciated 35 million years ago; and that sea levels will now rise continuously for several centuries – making any permanent settlement anywhere near the coast impossible (seeJames Hansen in Storms of my Grandchildren).
If your response to all this is to accuse me of being alarmist, all I can say is that I am afraid denial is definitely not a good evolutionary survival mechanism. Furthermore, as American high school science teacher – and now climate change activist – Greg Craven has said,“Unfortunately, the experiment is already running; and we are all in the test-tube!” I believe we must therefore hope that humanity will not repeat the folly of the former inhabitants of Easter Island; who chopped down all their trees for firewood and allowed all the decent soil to be washed away so they could not grow anything.
I think it is fair to say that 2011 was a difficult year for humanity and the planet; and 2012 could be worse. We now seem to be facing both a financial and an environmental crisis: Even at the tender age of 46, I can appreciate that the prospect of 6 years of austerity measures (here in the UK) is completely without precedent; worse even than the great depression of the 1920s. In the UK, public sector workers have been demanding a better pension! What about a better economic system, or even a better planet? If necessary, please forgive my impertinence but, how can people demand justice for themselves whilst ignoring all the injustices we are inflicting on those least able to adapt; and/or bequeathing to our descendants?
This is almost as pessimistic as my recent answer on ClimateSight to the question “Why are people who want to reduce – and possibly eliminate pollution – and create a safer world, considered obstructionist naysayers?“, which is… “If everyone lived as we do in ‘the West’, the planet’s ecological carrying capacity would only be about 3 billion [Paul and Anne Ehrlich (1996)]. Therefore we cannot solve poverty without allowing a lot of people to die or by wealthy people agreeing to moderate their over-consumption of the Earth’s resources. Sorry to be so blunt but, this is the simple answer to the question.” …Despite what detractors say this is not misanthropic eco-Socialism, it is reality. There is not enough decent farmland and/or resources of every kind for 7 billion people or more to live like we currently do in ‘the West’. If we are not going to deny the legitimate aspirations of poorer peoples to attain a better standard of living, we will have to moderate our over-consumption and/or pollution of the Earth’s resources. We cannot have it both ways.
If we continue to burn all the Earth’s fossil fuels – just because they are there and because we can – we will most certainly have to say good bye to our Goldilocks Planet. However, now that we know that what we are doing is causing the problem, would it not be a good idea to stop doing it? You know: When in a hole, stop digging, etc… As the Good Book says, “As a dog returns to its vomit, so a fool repeats his folly” (Proverbs 26:11).
Suggested New Year’s Resolution:
If we want things to change, I believe we must acknowledge that Clive Hamilton is right: climate change is a failure of modern politics – representative democracy is not working! Therefore, we must all take a much more active role in the process of government – this is called participatory democracy – and we must start by demanding that our politicians dismantle (or at least stop being misled by) the fossil fuel lobby who do not want their business as usual programme interrupted.
Having said all that, I would still like to sincerely wish you all the best for 2012 (although I hope the Mayan Calendar is wrong).