March 18, 2009
(Warning: this post contains liberal worrying and extreme use of graphs. Reader discretion is advised.)
Until recently, scientists spoke of carbon concentrations – and temperatures – peaking and then falling back. But a recent paper in the Proceedings of the National Academy of Sciences shows that “climate change … is largely irreversible for 1,000 years after emissions stop”. Even if we were to cut carbon emissions to zero today, by the year 3000 our contribution to atmospheric concentrations would decline by just 40%. High temperatures would remain more or less constant until then. If we produce it, we’re stuck with it.
This seemingly innocuous passage came from Gorgeous George Monbiot’s comment piece in yesterday’s Guardian. Read it again and try and stop your mind boggling at this fact: even if carbon emissions ceased today, concentrations will only have halved in a thousand years time? Like most science it seems unlikely but is very much a sincere possibility. It also highlights one of the major facts that policymakers tend to overlook; carbon emissions have an obscene shelf life. What we emit now will stay with us for a long, long time.
Basic theory on global warming runs as follows; the sun’s rays enter the atmosphere and warm the Earth. Some of this heat gets reflected back from the surface but gets trapped by the atmosphere, thus keeping the surface at a reasonable temperature. However the emission of carbon dioxide (amongst other gases) accumulate and trap more of the sun’s heat then before. This is the foundation of the famous ‘greenhouse effect’ which is the main cause of global warming.
Naively, one would think that by shutting off carbon emissions it will stop its accumulation and stop the greenhouse effect. This does not consider the already existing gases which still has an impact on warming. It is these existing gases that Solomon et. al. investigate in the paper that was mentioned above. (Even better, the paper is currently open access so anyone can download it and check it, as should be the case with all scientific literature.)
Using existing and established climate models, they simulated the case where carbon emissions were allowed to accumulate to a series of set values, before stopping any output. They then measured how the existing emissions decayed and what their ‘steady-state’ levels were; that is, what the values would be like when decaying forces ceased to act.
The results, as you can guess, do not inspire confidence. Instead of carbon dioxide going away, it only slowly decays and will still stay at high levels after 1000 years. As George Monbiot pointed out above, only 40% will dissipate on average. Why is this? The researchers note that around 50% of atmospheric carbon dioxide can be retained by the atmosphere and so will have a hard time going away. Also, the vast oceans of the world absorb such gases and emit it at later times, which replenish any pollution which may otherwise have gone away.
Sexy graphs: the top one shows how carbon dioxide dissipates slowly over time, with the bottom one describes what effect this may have on surface temperature.
Obviously as carbon dioxide will still be present, there will still be a greenhouse effect. Again, this does not bode well for humanity, with a temperature rise of two to four degrees predicted. Note that this is assuming that no further emissions occur after a cut-off point; what will be the actual rise with some emissions still in place, as will happen in reality? I shudder to think at that one.
Solomon et. al. then investigates how this affects precipitation and sea levels. If there is a mere two degree increase in temperatures, North Africa and Southern Europe will be worst hit, they predict, as they will suffer the most obvious reductions in precipitation. Mexico will also be badly affected. Mull on this for a moment; these are mainly poorer areas of the world which will suffer a heavy blow which will affect water supplies, agriculture and desertification. Sea rise is also inevitable due to a combination of icecaps melting and thermal expansion (that is, hot things which naturally expand). The rise will be around half a meter to a meter high, and could be as big as two meters. Doesn’t sound like much, but this is still plenty of water which can submerge many coastal features and towns.
This post and the paper may be depressing; it might say to you that no matter what one does about reducing their carbon footprint, dangerous climate change is inevitable. This should not be the case. The main effects depends on how much we output now, as well as reducing any emissions in the future. If this is stemmed immediatly, then the changes will be slight and the damage minimal; hopefully it can also be negated by human ingeniousness. Start these reductions today to save tomorrow.
(Reference; Solomon et. al. “Irreversible climate change due to carbon dioxide emissions”, Proceedings of the National Academy of Sciences of the United States of America, 106(6):1704 – 1709,2009.)
March 12, 2009
Posted by thestochasticman under EUSci
| Tags: EUSci
"Stochastic Man? More 'funny peculiar' rather then 'funny haha'."
Rejoice! As the latest EUSci podcast has been released for your pleasure. If anything, have a listen to hear my rather cheesy introduction which I volunteered at the last minute. Our Alan has nothing on me.
Or, listen to catch up on the best science stories of the last fortnight including a possible AIDS cure; quantum mechanics observed; Edinburgh’s stem cell breakthrough; and the ‘Daily Mail’s Cancer Fail’. Enjoy!
March 9, 2009
This is rather exciting. The excellent David Colquhoun of DC Science is coming up to Auld Reekie to give a talk on pseudoscience and quackery. If anyone is around Edinburgh on the 20th March I thoroughly recommend you pop along to Appleton Tower and hear him.
For those who’ve yet to hear of him, you should stop what you’re doing now and visit his webpage. David Colquhoun (described by Ben Goldacre as “The funniest man I know”) regularly blogs in his typical sardonic fashion on the onset of fake medicine and the “Endarkenment”. This is going to be brilliant.
March 8, 2009
ADX Florida, one of America's 'Supermax' prisons
Yesterday I spent a fun day in sunny Glasgow as part of the Aye Write! literature festival. One of the speakers was the always entertaining and witty Steve Jones, the geneticist and writer from UCL and alumnus of Edinburgh University. He spoke on modern aspects of evolution and genetics, but what stuck most in my mind most from his talk was nothing about science, but something on US penal policy instead.
When discussing the social behaviour of animals, Professor Jones made reference to Richard Reid, the infamous shoebomber. Unable to be put to death, he was instead sentenced to life imprisonment in one of America’s ‘Supermax’ prisons, ADX Florida. Within these, prisoners are kept in solitary confinement under surveillance via close-circuit TV; they are only allowed to leave their cell for one hour a day and this is usually for exercise, which has to be done alone. Cells are soundproofed, gray and featureless, and inmates are fed on ‘junk loaf’; food containing no stimulating flavour whatsoever.
In other words, the whole experience is made to deprive all prisoners of stimuli and contact with other humans. When Richard Reid was sentenced, the judge told him “You will die alone, the only sound you will hear is your own whimpering”. “Except,” warned Prof. Jones, “No-one in these prisons ever dies with a whimper but with loud screaming, as they inevitably lose their minds.” Humans, like most animals, are social creatures; we thrive and live on the contact we make with other members of our species. Remove that contact, and we would not know what to do. Except lose our minds and souls.
Further evidence of Supermax prison’s damaging effects is present in this rather weighty report by Craig Hanley of the University of California, Santa Cruz. (Unfortunately in order to read the whole thing you need access through an academic account, which is always inconvenient and silly.) At 34 pages long, it outlines in painful detail the individual mental, physical and sociological problems caused by these intense prisons. As such, it is more depressing then listening to Portishead whilst residing in a bedsit in Slough.
More specifically, he found that prisoners in these cells suffer from increased rates of “Negative attitudes and affect; insomnia; withdrawal; hypersensitivity; ruminations; cognitive dysfunction; hallucinations; loss of control; irritability, aggression, and rage; paranoia; hopelessness; lethargy; depression; a sense of impending emotional breakdown; self-mutilation; and suicidal ideation and behaviour.” So nothing too major then.
In fact, as part of his literature review, he found that “Many of the negative effects of solitary confinement are analogous to the acute reactions suffered by torture and trauma victims, including post-traumatic stress disorder or PTSD and the kind of psychiatric sequelae that plague victims of what are called ‘deprivation and constraint’ torture techniques.”
Overall it was found that all studies in which prisoners were placed in supermax prisons with no control over their release showed increased rate of mental illness. Now, some of the more skeptical readers may ask, “Is this the fault of the prisons themselves though?” This should be addressed, as more aggressive criminals would be placed in supermax prisons and are the people more likely to suffer from mental illness. This may account for an increased rate, but this cannot be helped and is surely worsened by the increased social stress and isolation which supermax prisons impose. (There is also the increased rate of physical illness that occurs, which does not seem to correlate with criminal behaviour.)
To me, supermax prisons are a shame on America’s penal system and a shocking form of punishment in a so-called developed country; the United Nations has already described them as “inhuman and degrading”. I’m sure you’ll join me in agreeing that penal systems are their to punish but also rehabilitate; how the hell can this be possible when the inmates are effectively tortured for years and their mental state systematically broken down? If you’re as angry as I am with this, I’m not sure what I can suggest to improve this situation except note that there is a link to Amnesty International to the right.
(Reference: Hanley C., “Mental Health Issues in Long-Term Solitary and “Supermax” Confinement”, Crime & Delinquency 49(1), 124-156 (2003). DOI: 10.1177/0011128702239239)