LONDON - So what does 2009 hold in store for us? As ever, the unpredictable - a terrorist atrocity or a rash decision by a national leader - will take its toll. But much of what happens tomorrow will be a result of history.
In the last century, the world's population increased four-fold, and the number of people living in cities thirteen-fold. The world's output grew by a factor of forty, water use by nine, energy use by thirteen, and the emission of carbon dioxide by seventeen. The twenty-first century has to live with the consequences of all that, good and bad.
Some of the factors that will shape our lives appear to tug in different directions. The age profiles of our societies are changing dramatically. Asia and Europe have experienced sharp falls in fertility rates. The figures in Hong Kong, Singapore, and South Korea are even more remarkable than those in Catholic European countries like Spain, Italy, and Poland.
At the same time, people are living longer, so that in a generation the number of elderly dependents in some countries will outgrow that of the young. We have been accustomed to societies with a demographic structure that resembles a pyramid - a broad youth base tapering to an elderly tip. But now the structure is more like the profile of a skyscraper, more or less the same from top to bottom.
Our older populations have to cope with ever younger technology. This expands educational and employment opportunities. Many students today are being prepared for jobs that do not yet exist. Moreover, some sorts of knowledge can rapidly become redundant.
Indeed, half of what a student learns in the first year of a four-year technical course will be out of date by the third year. Change itself accelerates. Its results are magnified. Its benefits and its disadvantages penetrate more deeply. Every month there are 31 billion searches on Google. It took radio 38 years to reach an audience of 50 million. Facebook did that in two years.
We usually reckon that it is easier for young, unformed minds to handle changes like these. How does someone like me, at university in the early 1960's, adapt and cope? How will older societies manage new technology and remain dynamic?
The biggest challenge for all of us, young and old, next year and for the indefinite future, will result from a different sort of change that is unlikely to respond simply to technological determinism. It results from the way we have been living for two centuries. If older leaders do not produce the right answers soon, younger generations will reap the whirlwind - sometimes literally.
2009 is supposed to see the conclusion of an agreement on global warming and climate change to succeed and build on the Kyoto Protocol. Copenhagen is the venue for the meeting. Optimists cheer the departure of the Bush administration and assume that the arrival of the Obama presidency, which unlike its predecessor is not in denial about the science of global warming, will unlock the prospect of a deal. Pessimists note that our mounting economic woes around the world are being used as an excuse for inaction on cuts in carbon emissions.
But continuing to use energy inefficiently will not mitigate the painful effects of the global economic crisis. If we make today's problems the excuse for failure to save the environment, we will simply pile up much bigger - and potentially catastrophic - problems tomorrow.
China, the biggest of the emerging economies, clearly understands this. Whether India does as well seems to me rather more doubtful. China faces its own environmental dangers, for example, water stress. It does not want to see its industries outdated and uncompetitive. China will work for a global consensus on climate change. The big question is whether it will be able to impose tougher environmental standards throughout the whole country.
For America, the problem is also mainly one of domestic politics. There will be no worthwhile American offer on the environment until there is a deal in Congress. This year's task may be to reach a global understanding in Copenhagen that is not too prescriptive, but which is more than aspirational and into which an American domestic political agreement can be incorporated once Obama achieves it.
But all of this sensitive diplomacy could be wrecked if, in response to rising unemployment, there is an outbreak of trade protectionism involving America, Europe, and China. That is when the economic and environmental agendas could fatally collide.
So young and old alike should hold onto their hats in the exciting but dangerous years ahead. All of us must hope that the first Internet-generation American President can lead his own country and the rest of humanity into a safer and more sustainably prosperous future.
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