KEY POINTS:
Edited by Ralph Chapman, Jonathan Boston and Margot Schwass
Published by Victoria University Press
The issue of climate change and what to do about it has lately moved from the back roads of the political landscape to the highway.
That imparts an extra timeliness to this collection of 29 contributions to a two-day conference held at Te Papa last March to debate what is one of the great issues of our day.
It is hard to think of another area of science in which people who are not practitioners of that science get as dogmatic and heated as they do about the climate.
There are, however, scientists who are entitled to be listened to on this matter, and several of them contributed to the conference and the book.
What they say makes for uncomfortable reading.
That makes the upbeat assessment of the technological options for tackling climate change from former Shell chairman Lord Oxburgh, and of the relatively modest economic price tag for doing so from economist Steve Hatfield-Dodds all the more encouraging.
But first the bad news.
We are told of the prospect of an increase in average world temperatures of 2C or 3C. With nothing to calibrate the scale, that can sound positively inviting.
Professor Peter Barrett from Victoria University of Wellington is one of the Kiwi scientists who goes to Antarctica to drill holes thorough the ice and into marine sediments below to get a long-term perspective. It seems that lately (the past 14 million years or so) it has been an "icehouse" world, marked by persistent ice at the poles even during periods, like now, of interglacial warming. It wasn't always so. The climate we know and have adapted to is the result of a cooling trend 50 million years long.
"It is now becoming clear that this long-term cooling trend may have been reversed in the past few decades," Barrett says.
With business as usual by the end of the century, and the Earth 3C warmer, the climate will have risen out of the icehouse state of the past 14 million years and before much longer will returned to the greenhouse world the dinosaurs knew.
"Even an increase of 3C would mean the loss of Arctic sea ice, the low-mid latitude glaciers, the Greenland ice sheet and most likely that of West Antarctica - bringing a total rise of about 12m in sea level."
Sir Ian Axford, director emeritus of Germany's Max Planck Institute, warns of the risk that the two great carbon sinks - forests and oceans - which take carbon dioxide out of the atmosphere may turn into sources of emissions if things get warm enough.
Professor Will Steffen from the Australian National University reflects on the risks that current models may be underestimating the scale of global warming ahead.
"There is still much uncertainty in the science," he says, "but the present indications are of increasing risk that the temperature rise by 2100 will be more than 2C, rather than less."
He cites data from Antarctica ice cores which shows that today's level of atmospheric CO2 is well above the top of the range of at least the last four ice age cycles - the normal operating range, that is, of the world in which mankind evolved.
So what can be done?
About a third of the book is devoted to that, one way or another.
Lord Oxburgh, chairman of Shell until last year, takes some comfort from the fact that we turn over the capital stock of our most energy-hungry assets on "relatively short" time scales - 10 to 15 years for cars, 40 years for power stations.
"Therefore affordable change at minimal cost is possible if we change our thinking about infrastructure now."
For cars he suggests more efficient propulsion from hybrids or fuel cells, and the use of biofuels. Professor Ralph Sims from Massey says the residues left by the forestry industry in New Zealand equates to about 50 petajoules of energy a year, the equivalent of a natural gas field.
ANU economist Steve Hatfield-Dodds reports on a study commissioned by the Australian Business Roundtable on climate change which looked at the economic effect on Australia if it cut its greenhouse gas emissions 60 per cent by 2050.
The bottom line is that the Australian economy would grow at an average rate of 2.1 per cent a year between now and 2050, instead of 2.2 per cent if no action was taken.
The Australian economy would still double in size by 2015 - two and a half years later than if no action were taken.
The rise in electricity prices, for example, would be matched by rising incomes. But the effect on Australia's emissions (per capita among the highest in the world) would be dramatic: 60 per cent lower than now versus 77 per cent higher on a business as usual basis.
No one suggests getting on top of climate change will be easy, however.
Former Environment Minister Simon Upton represented New Zealand at Kyoto in 1997 when the climate change treaty was drawn up and now heads the Organisation for Economic Co-operation and Devlopment's round table on sustainable development.
Developing countries' emission, now 40 per cent of the world total, will be more like two-thirds by mid-century.Their right to develop is jealously guarded, Upton says, and it will be exercised.
So we had better hope that clean technologies that make sense to them emerge and are diffused in time. Otherwise it is game over.
* Published by Victoria University Press
