This is the last day of the old millennium. In less than 24 hours the twentieth century will be over. As we approach tomorrow, it is impossible to avoid a certain apprehension. Are we are walking into light, or over a cliff? Lacking a crystal ball, we must look to the past as our only view of the future. Perhaps where we have been may yield clues about where we are going.
I don’t for one minute think it is possible to predict the future. I look to the past for a different reason, as a Rorschach ink-blot test of my own scarce-recognized intuitions. The history of science is so rich and complex that no two scientists will see it the same. Looking back over yesterday’s discoveries, each of us will take away different lessons, not easily articulated even to ourselves.
The accompanying table presents in capsule form my look back. I find it much more useful to think in fifty year periods– roughly a life span — than in centuries. For the last three half-centuries I have noted what seem to me to be the major innovations in four categories: materials, medicines, inventions, and discoveries. Anyone else would select different items, and no one of you will read my lists without doubting the wisdom of a choice, or wondering how I could have been so stupid as to have omitted a particular item. Whatever its limits, however, this table reflects my “take” on the course of scientific progress as we approach the new millennium.
What then does the table reveal about my perception of past scientific progress? For one thing, I obviously see each half century as emphasizing particular themes. Consider “inventions.” I see the 1850-1899 period as featuring transportation (iron ships, cars) and subduing the West (dynamite, barb wire). The 1900-1949 period shifts to communication, with the advent of radio and TV. The1950-1999 period has been the information age, shaped by transistor-driven computers.
Of course not all advances fit this simplistic scheme. The airplane appears just after the age of transportation, in 1903, the transistor just before the age of information, in 1948. But the synergy of scientific progress seems to me a clear pattern, coordinated advance over a lifetime of discovery.
Is any more general pattern evident in my overview of science past, any clue about the likely direction of scientific progress in the next millennium?
I have thought about this table for a month, preparing this column, and only gradually have I come to understand its true message. If you stand back from its detail and ask, “What is its essence?” a clear pattern snaps out at you, one that says a great deal about the probable future of science in the next century. Overwhelmingly, this table presents a picture of science at work promoting growth. For a century and a half, science has been the engine of society’s conquering of the planet. This leads to a clear prediction about science’s future, which is that science is going to have to change its focus, and drastically. Consider for a moment the last half-century. What the table does not tell you is that at the beginning of this period, in 1950, the world’s population stood at 2.5 billion people, while at period’s end, in 1999, the world contains 6 billion people.
It is difficult to overemphasize the impact this change will have on the planet’s future. The cost of getting the food to feed the 3 1/2 billion added people has been that we have begun eating into the world’s nonrenewable resources. In a banker’s terms, we are spending our capitol, lowering earth’s ability to support us. Over the last fifty years, we have lost 25% of the world’s topsoil, one third of its forests, and fully one quarter of its agricultural land. We have added 15% to the level of carbon dioxide in the atmosphere, unleashing global warming. We have released chemicals that have destroyed 6-8% of the atmosphere’s ozone, leading to a 20% global increase in malignant skin cancers.
According to the most conservative estimates, we will add 2.9 billion more people in the next fifty years. How are we to care for them, and at what cost? We are using 55% of the world’s available fresh water and 45% of the world’s net terrestrial photosynthetic productivity (that is, all the food photosynthesis could possibly make) now, to feed 6 billion people, with one half of the world’s population malnourished and one quarter living in extreme poverty (at less than $1 per day).
No amount of science can overcome the finite nature of the world we inhabit. If we are to have a future in the next millennium, science will have to focus not on growth, but on sustainability. My take-home lesson from thinking about science and the new millennium is that we as scientists desperately need to redirect our focus toward solving the problems that are rushing towards us, rather than continuing to fuel the rush towards them.