Back in the 1970s, an elite group of scientists, researchers and consultants had researched and debated about the
future growth of the world economy, using computer models developed at MIT.
The models assumed no major change in the physical, economic, or social relationships that governed the civilization for the last 100 years. As the world population grew exponentially from 1900 to the middle of the 21st Century, the growth trends in industrial output, food production, pollution and resource depletion would also increase correspondingly. There would be a time lag among the peaks of these trends. The industrial output, food production and resource depletion would come to their peaks first, and later the pollution, and then finally the population, as shown in the figure.
Looking back to the past 50 years, the predictions by the Doomsday Models
seems to be basically fitting the reality. The industrial output is still expanding
especially for the developing countries, such as China, India and Brazil; however,
the GDP growth for western countries is now stalling and short of capital after
a severe financial crises in 2008. There are no global famine as biotechnical progress
and industrialization in agriculture have provided higher yields, although the capital countries from Middle East and
Asia are yearning for agricultural lands in Africa. Pollution (air and land) are improving in developed countries,
but the qualities of sea water are now deteriorating rapidly. Resources in minerals,
energy and renewable natural stocks with the exception of fresh water are still keeping up
with the demands due to new explorations and extraction techniques by
resource industries and the recycling efforts and more efficient usage of resources.
The world population is still growing remarkably - 4.5 billion in 1980, 5.3 billion in 1990, 6 billion in 1999. According to US Census Bureau, the world has more than 7.056895 billions of people on January 1, 2013. Thus, one has to be an optimist to brave the future and hopes the changes in growth trends, the developments in technological progress and the social behaviours will fend off challenges in the world.