We not only practice farming to feed ourselves. An increasing quantity of land is now used to produce non-edible goods such as paper, clothes, or fuel. Cotton fields, for example, comprise 2.5% of the world’s farmland, yet absorb 25% of all pesticides used. As for eucalyptus, the area devoted to its cultivation has multiplied fivefold in fifty years, as paper consumption has risen. It grows rapidly but requires a lot of water, and few birds and plants are able to adapt to the presence of this tree, imported from Australia.
Tea, coffee, and cacao are other export products that are not subsistence crops, but they bring in taxes for the governments and income for farmers, and so have been encouraged. They often take up the best land and their growth, which is linked to booming populations, turned some countries that were formerly self-sufficient into food-importing nations over the course of the 20th century.
Even grain crops are not always used to feed mankind: more than half of those that are exported are used to feed livestock or turned into biofuels. They are cultivated on deforested land or in areas where subsistence crops could potentially be grown. In order to put an end to this competition for land, between plants used to feed people and plants used to feed engines, specialists are working to develop what are known as second generation biofuels. These use the non-edible parts of subsistence crops, such as straw, and could be grown on the poorest of land, but they are still at an experimental stage.
If all available land was used to grow have been encouraged. They often take subsistence crops, the planet would have plenty to eat. But farmers would still need to be guaranteed a decent income, and a way of sharing out this food and transporting it to those in need would have to be found.