Rune,
We are very close to not having enough food for the whole world. The main reason that the “doomsday” people were wrong in the 70’s was the “green revolution” of modern mechanized farming using high yield crops with lots of fertilizer and pesticides. This produced years of bumper crops.
But the gains are getting smaller, and the amount of cropland worldwide is declining (farms turned into homes, land becoming over-used, aquifers running out, etc). But that trend is still pretty slow, things would be fine for a long while.
The trend that will hurt food production the most is peak oil. That is the amount of readily available easily producible oil is reaching a peak (at the halfway point of resource use there is a peak in production mostly due to the fact of using the easiest to get to oil first with the harder to reach coming later). In other words, we will soon have to deal with less and less available energy - and oil in particlur (and natural gas) is very important to modern mechanized farming, from the energy to run the tractors/harvestors to the energy for pumping irragation water, to the feedstocks for many pesticides and fertilizers, to the transport of raw food for production, to the transport of finished food products, etc.
Energy problems will force the world into food shortages, medicene shortages, etc.
The population of the world is still growing, but soon (10 years or so) it will be falling, and not because of lower birth rates, but from higher death rates (war, famine, disease).
If we had been more careful as a society with the oil resources, and worked harder to develop the poorer countries (so that we all reached the level of lower birth rates together) we would have done better than this grow grow - grown until we’ve outgrown the carrying capacity of our environment.
Check these links for verification :
http://www.simmonsco-intl.com/
http://www.princeton.edu/hubbert/index.html
Best Regards
adamant