Don't sweat climate change - research and development will being advances we can't imagine, just like people living in 1900 couldn't imagine the cities of today.
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Over the centuries we've been responsible for wars, chemical and nuclear accidents, the spread of disease, depletion of resources, habitat and species destruction as well as experiencing the full range of natural hazards, humanitarian disasters and pandemics that have had shocking and permanent effects.
Yet from a historical and global perspective, a reversion to a positive trend occurs, albeit over generations, wherein new technologies and improved social and political processes combine to produce continuing improvements in average global standards of living, and futures unconstrained by the past.
Climate model forecasts, however, suggest that runaway climate change might defy this history and so demands urgent and costly preventive measures. Runaway climate change will occur when a process - such as global warming or melting of Greenland ice - continues, or even accelerates, under the influence of positive feedback, with irreversible consequences.
An example of positive feedback is when large white ice sheets melt, which then reduces the reflection of incoming sunlight and increasing solar energy absorption by the darker underlying surface, exposed rock or sea, which in turn further increases temperatures, which leads to more melting, and so on.
A textbook example of irreversible climate change is the planet Venus, which started its warming journey three to four billion years ago and evolved from a water-bearing environment to a toxic inferno. But is the threat of a billion-year transition what alarms us today?
Self evidently, there has been no consequential runaway event in the 15,000 years of modern man since the last ice age, or even in the million-year span of human existence. Climate and environment appear to have followed patterns understandable to us today. Certainly, strong climate cycles have shaped the Earth's history, but concerns about runaway effects arise from complex climate models whose predictions are sometimes disputed.
But the industrial era has produced two forces that seem capable of triggering runaway-like effects on our environment: population growth and associated energy production.
Global population has increased from one billion people after the start of the Industrial Revolution about 1800 to nearly seven billion today, with a four-fold increase in the past 100 years alone. This looks like a runaway trend. But the world's population is now confidently forecast to level out near 10 billion people during the second half of this century.
Energy production and consumption loosely follow population growth but accelerate as the standards of living in the developing nations catch up to the West. As a result, global energy output will increase two or three times by the century's end.
Nuclear
Another measured and rational response amongst alarmism from both ends of this current polemic, thanks Ziggy. Interesting - especially given your current position - you didnt throw nuclear in the mix of current solutions. Tom
Ice ages
To reverse the melting debate and the positive feedback, why didnt the Earth freeze over in the Ice Ages? Colder and colder, more reflection of solar radiation......
Positive feedback with Arctic melting
I question Switkowski's claim that the dark open waters of the arctic result in runaway melting. The hours of darkness predominate, during which the open water should radiate even more heat to outer space than snow or ice. In addition, the incidence of the sun's rays during daylight are such that the dark waters should reflect most of the sunlight rather than absorbing it. The ice and snow would tend to scatter the light rather than reflect it, resulting in eventual absorption. My conclusion would be that the polar ice caps are self-regulating, tending toward a situation where some ice always forms in the winter time.
R Heintz
the trouble with R&D
Ziggy is right that R&D is likely to produce amazing changes over the next century and that it may make any worries about climate change just a storm in a tea cup.
The only problem is that R&D output is intrinsically unpredictable. In the 1950's, nuclear fusion was going to make electricity too cheap to meter in 20 years. Fusion is still 20 years away after 60 years of R&D with billions of dollars of funding.
The other issue is that sometimes it is far cheaper to avoid making a mistake than to try to fix it afterwards. A good example of this is the introduction of rabbits into Australia. The cumulative cost to farmland productivity is well into the billions. (and CSIRO's R&D has also failed to deliver a fix so far) If, pre-introduction, someone had stopped to consider it, the cost of keeping rabbits out of Australia would have been much smaller.
So perhaps "in any policy choice between economic growth and more conservative, restricted lifestyles" the best course is somewhere between these two extremes.