Please allow me to redress the balance in your magazine concerning Climate Change. As a Catholic, I see social justice in concern for the people of the future. As a Professional Engineer, during 2006/7 I undertook a detailed study of the science, and I conclude that the world is in trouble. Nothing since persuades me that the scientific consensus is wrong, or the outcome of dishonesty among scientists. As a grandfather of 10, for the sake of my descendants, I seek urgent action.
It is not possible to predict the occurrence or magnitude of climatic impacts. Studies of multiple scenarios enhance understanding and add confidence in climate models, and risk management principles further reduce uncertainties. The consensus is that by 2100 we are likely to see an increase in average global temperatures above 15°C by 2 to 4 degrees. Because that is the fruit of collaboration, it is conservative. The rise could be a catastrophic 5.8°C.
There remain marginal factors of uncertainty about precisely how the oceans, the forests, the grasslands, the Polar Regions, and the weather respond to greenhouse gasses. We observe droughts, seasonal changes, sea ice-melts, methane escape from melting permafrost, and glacial retreats, all proclaiming a world in trouble. Marginal uncertainties do not negate what we know: that global warming is at a rate unprecedented in human history, primarily the result of increasing emission of greenhouse gasses from human activities.
Can we take the risk that this is all wrong, and do nothing? Melting of Antarctic and Greenland ice sheets within a decade seems possible, and it will very likely cause a global tipping point, beyond which the irreversible effects would overshadow the cost of mitigation measures, or local inconvenience. Wasting years arguing is negligent and dangerous - and stupid beyond measure. If we do nothing, as our descendants struggle to survive in a degraded future world, will they look back on our era and marvel at the complacency and parochialism of our negligence?
Getting greenhouse emissions down is the first priority and it is urgent; and Australia must take a leadership role. We do not have decades to dither around, playing politics with the future of the world.
DR BRIAN E. LLOYD, AM
Hampton East, Vic
(Dr Lloyd is an electrical engineer, a writer on history, and a past National President of Engineers Australia. His recent book is titled Global Warming and Climate Change.)