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Science could tell us if we have free will
New Science Publications
Editorial–
Editor Jeremy Webb Personal Asst & Office Manager Anita Staff Associate Editors Liz Else, Stephanie Pain News Editor Matt Walker Editors Helen Knight, Linda Geddes, Rowan Hooper, Celeste Biever Tel +44 (0) 20 7611 1206 Fax +44 (0) 20 7611 1250 Reporters LONDON Andy Coghlan, Hazel Muir, Paul Marks, Zeeya Merali [email protected] BOSTON US Bureau Chief Ivan Semeniuk David L. Chandler [email protected] Celeste Biever [email protected] Gregory T. Huang [email protected] SAN FRANCISCO Bureau Chief Peter Aldhous [email protected] Michael Reilly [email protected] Jim Giles [email protected] TORONTO Alison Motluk [email protected] BRUSSELS Debora MacKenzie [email protected] MELBOURNE Australasian Editor Rachel Nowak [email protected] Features Editors Ben Crystall, Kate Douglas, Clare Wilson, David Cohen, Graham Lawton, Valerie Jamieson, Michael Le Page, Caroline Williams Features Assistant Celia Guthrie Tel +44 (0) 20 7611 1201 Fax +44 (0) 20 7611 1280 [email protected] Opinion Editor Jo Marchant Editors John Hoyland, Amanda Gefter, Alison George, Eleanor Harris Tel +44 (0) 20 7611 1240 Fax +44 (0) 20 7611 1280 [email protected] Researcher Lucy Middleton Editorial Assistant Nick Christensen Production Editor Mick O’Hare Asst Production Editor Melanie Green Chief Sub John Liebmann Subeditors Vivienne Greig, Ben Longstaff, Julia Brown, Sean O’Neill Art Editor Alison Lawn Design Craig Mackie, Michelle Ofosu, Ryan Wills Graphics Nigel Hawtin, Dave Johnston Pictures Adam Goff, Kirstin Jennings Tel +44 (0) 20 7611 1268 Fax +44 (0) 20 7611 1250 Careers Editor Richard Fisher [email protected] Tel +44 (0) 20 7611 1248 Fax +44 (0) 20 7611 1280 Consultants Alun Anderson, Stephen Battersby, Michael Bond, Michael Brooks, Marcus Chown, Rob Edwards, Richard Fifield, Barry Fox, Mick Hamer, Jeff Hecht, Bob Holmes, Justin Mullins, Fred Pearce, Helen Phillips, Ian Stewart, Gail Vines, Gabrielle Walker, Emma Young Press Office and Syndication UK Claire Bowles Tel +44 (0) 20 7611 1210 Fax 7611 1250 US Office Tel +1 617 386 2190 NEWSCIENTIST.COM Online Publisher John MacFarlane Online Editor Damian Carrington Deputy Online Editors Shaoni Bhattacharya, Gaia Vince Editors Maggie McKee, Will Knight Reporters Tom Simonite, Roxanne Khamsi, David Shiga, Catherine Brahic, Sandrine Ceurstemont, Michael Marshall [email protected] Online Subeditor Dan Palmer Web team Neela Das, Michael Suzuki, Cathy Tollet, Ruth Turner, Ken Wolf, Vivienne Griffith, Rohan Creasey
www.newscientist.com
A timely warning There’s more to beating climate change than limiting carbon emissions THE world is starting to take note of its carbon footprint – and with good reason. Yet in the rush to cut carbon dioxide emissions, it is all too easy to forget about other pollutants whose contribution to global warming is just as worrying. Ozone smogs, acid rain and smoke were all targeted by environmentalists in the 1980s and 1990s for the local harm that they do. What is now becoming clear is that failure to tackle them could also upset the best-laid carbon schemes. This week veteran Californian atmospheric chemist Veerabhadran Ramanathan published his most alarming conclusions yet about the climatic impact of the “brown haze” that hangs over much of Asia each winter (see page 11). Its effects are complicated. Some components, such as acidic sulphate particles, scatter sunlight and shade the Earth’s surface. Others, especially black soot, absorb solar energy and radiate it into the surrounding air, causing warming. While it looks as if the haze has an overall cooling effect on the planet, Ramanathan calculates that in south Asia black soot may be doubling the warming caused by greenhouse gases. In particular, it may be accelerating the melting of glaciers across the Himalayas, with potentially devastating effects for the more than 2 billion people whose lives depend on their meltwaters. A second study, published last week in
Nature (DOI: 10.1038/nature06059) by UK-based researchers, looked at the climatic effect of ozone in smogs. Although it has a beneficial role in the stratosphere in filtering harmful ultraviolet radiation, ozone is also a greenhouse gas. Concentrations at ground level have doubled since pre-industrial times and continue to rise. Ozone’s direct warming effects are already well known. Now Stephen Sitch of the Hadley Centre for Climate Prediction in Exeter warns that it also has secondary effects whose impact on climate may have been drastically underestimated. Ozone smogs attack plants and this, Sitch says, could soon start to damage the ability of the planet’s vegetation to absorb CO2 from the air. Currently, plants absorb a quarter of all the CO2 we emit. Ozone smogs could cripple this vital carbon sink and accelerate warming. The lesson here is that we have to consider the feedback effects of all pollution, not just CO2. In this case, action may be on the way. The immediate effects of brown smogs are all too evident: ozone, sulphates and soot kill millions through lung disease and cut crop yields across Asia. As a result, China is banning coal burning in many of its cities, and though this has nothing to do with fears of climate change it could help to mitigate warming. It’s a timely warning to governments not to wait for catastrophes on this scale before taking action on all aspects of climate change. ●
Do we have free will? Ask a physicist FEW questions run as deep as whether we have control over our actions and decisions. Philosophers are still hotly debating it, but they are no longer alone. It has become as much a problem for neuroscientists, psychologists and physicists. When Nobel laureate Gerard ’t Hooft published a theory last year aimed at unifying quantum mechanics and general relativity, it caused an outcry because it implied that the behaviour of particles – and of ourselves – was predetermined (New Scientist, 4 May 2006, p 8). In response, ’t Hooft set out to redefine free will in an attempt to salvage it – or a version of it – from the jaws of his theory. His latest thoughts (see page 10) are sure to further inflame the debate.
Philosophical questions become scientific ones when they can be tested experimentally. Neuroscientists started considering free will when brain imaging allowed them to analyse people’s decision-making. One of the most successful deterministic interpretations of quantum mechanics was formulated in the 1950s by physicist David Bohm. Its survival is due not least to the fact that it has been impossible to disprove by observation, but now the game is changing. A new discipline that some call “experimental metaphysics” is opening up that has the potential to resolve many of the questions thrown up by theories such as ’t Hooft’s and Bohm’s. How free are we? This fundamental philosophical dilemma could one day by answered by physicists. ● 4 August 2007 | NewScientist | 5
Editorial–
Editor Jeremy Webb Personal Asst & Office Manager Anita Staff Associate Editors Liz Else, Stephanie Pain News Editor Matt Walker Editors Helen Knight, Linda Geddes, Rowan Hooper, Celeste Biever Tel +44 (0) 20 7611 1206 Fax +44 (0) 20 7611 1250 Reporters LONDON Andy Coghlan, Hazel Muir, Paul Marks, Zeeya Merali [email protected] BOSTON US Bureau Chief Ivan Semeniuk David L. Chandler [email protected] Celeste Biever [email protected] Gregory T. Huang [email protected] SAN FRANCISCO Bureau Chief Peter Aldhous [email protected] Michael Reilly [email protected] Jim Giles [email protected] TORONTO Alison Motluk [email protected] BRUSSELS Debora MacKenzie [email protected] MELBOURNE Australasian Editor Rachel Nowak [email protected] Features Editors Ben Crystall, Kate Douglas, Clare Wilson, David Cohen, Graham Lawton, Valerie Jamieson, Michael Le Page, Caroline Williams Features Assistant Celia Guthrie Tel +44 (0) 20 7611 1201 Fax +44 (0) 20 7611 1280 [email protected] Opinion Editor Jo Marchant Editors John Hoyland, Amanda Gefter, Alison George, Eleanor Harris Tel +44 (0) 20 7611 1240 Fax +44 (0) 20 7611 1280 [email protected] Researcher Lucy Middleton Editorial Assistant Nick Christensen Production Editor Mick O’Hare Asst Production Editor Melanie Green Chief Sub John Liebmann Subeditors Vivienne Greig, Ben Longstaff, Julia Brown, Sean O’Neill Art Editor Alison Lawn Design Craig Mackie, Michelle Ofosu, Ryan Wills Graphics Nigel Hawtin, Dave Johnston Pictures Adam Goff, Kirstin Jennings Tel +44 (0) 20 7611 1268 Fax +44 (0) 20 7611 1250 Careers Editor Richard Fisher [email protected] Tel +44 (0) 20 7611 1248 Fax +44 (0) 20 7611 1280 Consultants Alun Anderson, Stephen Battersby, Michael Bond, Michael Brooks, Marcus Chown, Rob Edwards, Richard Fifield, Barry Fox, Mick Hamer, Jeff Hecht, Bob Holmes, Justin Mullins, Fred Pearce, Helen Phillips, Ian Stewart, Gail Vines, Gabrielle Walker, Emma Young Press Office and Syndication UK Claire Bowles Tel +44 (0) 20 7611 1210 Fax 7611 1250 US Office Tel +1 617 386 2190 NEWSCIENTIST.COM Online Publisher John MacFarlane Online Editor Damian Carrington Deputy Online Editors Shaoni Bhattacharya, Gaia Vince Editors Maggie McKee, Will Knight Reporters Tom Simonite, Roxanne Khamsi, David Shiga, Catherine Brahic, Sandrine Ceurstemont, Michael Marshall [email protected] Online Subeditor Dan Palmer Web team Neela Das, Michael Suzuki, Cathy Tollet, Ruth Turner, Ken Wolf, Vivienne Griffith, Rohan Creasey
www.newscientist.com
A timely warning There’s more to beating climate change than limiting carbon emissions THE world is starting to take note of its carbon footprint – and with good reason. Yet in the rush to cut carbon dioxide emissions, it is all too easy to forget about other pollutants whose contribution to global warming is just as worrying. Ozone smogs, acid rain and smoke were all targeted by environmentalists in the 1980s and 1990s for the local harm that they do. What is now becoming clear is that failure to tackle them could also upset the best-laid carbon schemes. This week veteran Californian atmospheric chemist Veerabhadran Ramanathan published his most alarming conclusions yet about the climatic impact of the “brown haze” that hangs over much of Asia each winter (see page 11). Its effects are complicated. Some components, such as acidic sulphate particles, scatter sunlight and shade the Earth’s surface. Others, especially black soot, absorb solar energy and radiate it into the surrounding air, causing warming. While it looks as if the haze has an overall cooling effect on the planet, Ramanathan calculates that in south Asia black soot may be doubling the warming caused by greenhouse gases. In particular, it may be accelerating the melting of glaciers across the Himalayas, with potentially devastating effects for the more than 2 billion people whose lives depend on their meltwaters. A second study, published last week in
Nature (DOI: 10.1038/nature06059) by UK-based researchers, looked at the climatic effect of ozone in smogs. Although it has a beneficial role in the stratosphere in filtering harmful ultraviolet radiation, ozone is also a greenhouse gas. Concentrations at ground level have doubled since pre-industrial times and continue to rise. Ozone’s direct warming effects are already well known. Now Stephen Sitch of the Hadley Centre for Climate Prediction in Exeter warns that it also has secondary effects whose impact on climate may have been drastically underestimated. Ozone smogs attack plants and this, Sitch says, could soon start to damage the ability of the planet’s vegetation to absorb CO2 from the air. Currently, plants absorb a quarter of all the CO2 we emit. Ozone smogs could cripple this vital carbon sink and accelerate warming. The lesson here is that we have to consider the feedback effects of all pollution, not just CO2. In this case, action may be on the way. The immediate effects of brown smogs are all too evident: ozone, sulphates and soot kill millions through lung disease and cut crop yields across Asia. As a result, China is banning coal burning in many of its cities, and though this has nothing to do with fears of climate change it could help to mitigate warming. It’s a timely warning to governments not to wait for catastrophes on this scale before taking action on all aspects of climate change. ●
Do we have free will? Ask a physicist FEW questions run as deep as whether we have control over our actions and decisions. Philosophers are still hotly debating it, but they are no longer alone. It has become as much a problem for neuroscientists, psychologists and physicists. When Nobel laureate Gerard ’t Hooft published a theory last year aimed at unifying quantum mechanics and general relativity, it caused an outcry because it implied that the behaviour of particles – and of ourselves – was predetermined (New Scientist, 4 May 2006, p 8). In response, ’t Hooft set out to redefine free will in an attempt to salvage it – or a version of it – from the jaws of his theory. His latest thoughts (see page 10) are sure to further inflame the debate.
Philosophical questions become scientific ones when they can be tested experimentally. Neuroscientists started considering free will when brain imaging allowed them to analyse people’s decision-making. One of the most successful deterministic interpretations of quantum mechanics was formulated in the 1950s by physicist David Bohm. Its survival is due not least to the fact that it has been impossible to disprove by observation, but now the game is changing. A new discipline that some call “experimental metaphysics” is opening up that has the potential to resolve many of the questions thrown up by theories such as ’t Hooft’s and Bohm’s. How free are we? This fundamental philosophical dilemma could one day by answered by physicists. ● 4 August 2007 | NewScientist | 5