Food for all !

Global warming seems to be the prime concern of science - but an even greater threat of catastrophe looms - starvation !

By 2030, 8.3 billion people will walk the earth - and to feed them farmers will need to grow thirty percent more grain.

The problem is that the amount of farmland is shrinking annually. The urban sprawl swallows huge portions, great areas are lost to salt rising to the surface - and poor farm practices in much of the remaining land results in top soil being lost to erosion and wind storms.

Soil scientists have long been excited about a phenomenon called " Terra Preta ". Scattered around the world are patches of incredibly fertile soil which we are only just beginning to understand.

For a start, this top soil has a depth of a much as two metres, whereas ordinary top soil is shallow. It absorbs and holds water - and continuously bears far greater than average crops.

Whether by luck or by good management it seems that previous inhabitants replenished the soil nutrients by using discarded food scraps and the ashes from their cooking fires to create a higher Co2 content.

The carbon was trapped by the charcoal and over time evolved into a super soil that was able to provide the needs of crops to create abundant harvests.

It would seem that we may have the guidance of our forebears to solve two of our greatest problems. If we find a way to return the Co2 that is causing global warming to the soil, we can enrich our farmland and create the increase in the food supply we will need in the immediate future.

It seems so simple. We need to add to our soil a medium that will absorb and hold Co2 - and this could be anything from pellets of soft rock such as sandstone, or some industrial waste product that has an absorbent tendency.

Then it would be a matter of capturing Co2 emissions from producers such as power stations and pipe it underground - to be absorbed by the medium we have added to the soil.

Sometimes the answer to complex problems are simple - and staring us in the face. It would certainly be worth creating a test site to examine the theory.