The growing world population means there are more mouths to feed. Many in the poorer countries spend up to 70% of their income on food. More animals are fed on grains, as people in emerging countries like China and India, want to eat more meat. Machines are competing with people in the use of land to grow crops to be converted into biofuels, rather than growing food to feed people.

There is an emergency food crisis. Food riots are becoming more frequent in many poorer countries, as food becomes more scarce and prices soar. The UN's Food and Agricultural Organisation (FAO) needs an additional £250 million just to pay the rising price of the food it needs for its current emergency programmes. On top of this, more emergency feeding programmes will be needed, if millions of people are not going to starve.

Waste is very expensive, whether it is heat from a badly insulated house or the unnecessary waste of food. We could save money by cutting down on the waste of food, both in the home and when we eat out. Much food is often left on our plates uneaten or in the saucepans on its way to the bin. If you have a pub meal, plates groaning with food will be served up – looking lovely and appetising. But all too often there is more food than we can eat and the rest is wasted. This could be cut, if pubs and other eateries provided smaller helpings with the possibility of 'seconds'.

Meat is expensive, not just in money terms, but also in the high use of food grains in its production. Having more vegetarian meals might not please the butchers, but could make more cereals available to feed people.

Enough and affordable food, access to clean water and combating damaging climate change are three great issues facing humanity. These need national and international action. But there are some things which we can do as individuals, and we should do them.