On World Environment Day, let's think about how we can better use the earth's resources.

WORLD Environment Day this year should pierce the minds of more Australians than ever before. As we feel the pinch at the petrol pump our leaders are flinging solutions at us such as tax cuts and biofuels. In the meantime, across the globe, there is a massive food crisis brewing that is already threatening 100 million people.

The two patterns are intimately linked. In our quest for fuel we are creating a global food shortage and driving the world's poorest towards a famine. It is incumbent on rich developed nations like ours to radically rethink the way we live on this planet. There is plenty for everyone, but we will not feed the poorest in the world if we do not change the way we act both globally and locally. Globally, we must work to end market distortions.

Restrictions and bans on food exports are a growing problem. At the Food Summit in Rome this week UN Secretary-General Ban Ki-moon urged world leaders to stop trade barriers and price controls. This is a well-informed plea because trade restrictions push international prices up further.

Already the price of food commodities on the international market has risen by 83% in the past three years. The price of rice doubled in the first four months of this year.

Export bans are also short-sighted, because as Cambodia and the Ukraine (who have lifted their bans) have realised, in the long-term they expose their own poor to price hikes when the bans are eventually lifted.

Instead of export bans that cripple the poor, we need positive trade outcomes. Here our own Government can help by increasing its efforts to achieve pro-poor outcomes of the Doha trade round.

Another big market distortion is biofuels. This trend for "other" sources of energy is well meaning but has terrible consequences for the poor. Biofuels alone are estimated to have increased food prices by up to 30%. This is dramatic for the poor, who spend about three-quarters of their income on staple foods.

The International Food Policy Research Institute estimates that by 2008 existing plans to expand biofuel production will push the price of edible oils up by a further 19% and corn by 26%, which will directly affect Africa.

Carving up the rainforests of poor nations to grow biofuels must be the most selfish act of all, though.

Each year Indonesia loses about 2 million hectares of its rainforest, much of it to palm oil, and about 20% of it is exported as biofuel to rich, energy guzzling nations. A European company has just gained the rights to grow biofuels in Ethiopia.

Apart from the devastation mono-cultures like this have on soil and wildlife, this trend is pushing poor farmers, whose survival depends on land to grow food, onto increasingly marginal land where crops struggle to grow. We will not end the energy and food crisis by using land this way and subsidising food to fuel our engines. It makes neither economic nor ecological sense. We must stop distorting markets with things such as subsidies on food-based biofuels.

There is also much we can do by simply helping the poor grow more food.

We can increase the productivity of land in poor nations with simple changes to farming methods.

Twenty years ago the Maradi district in Niger was a dust-choked, barren wasteland. Today 5 million hectares of once degraded land is a lush, productive forest, supporting thousands of families with food, fuel and shelter.

The solution was simple. Farmers were encouraged not to cut down trees, but instead to prune them, creating fertile orchards and vegetable gardens.

Economist Jeffrey Sachs, who argues we can increase food output four to five times in poor nations with better farming practices, has called for a $US5 billion ($A5.2 billion) investment to help small farmers expand agriculture. The World Bank this week announced $US1.2 billion in agricultural grants for the world's poorest nations.

These levels of investment are exactly what is needed and could be spent on the same simple and relatively inexpensive changes to farming practices introduced in Niger, such as crop rotation and diversity, reforestation, better water management and better storage.

As much as a third of all grain grown in poor nations is lost to bad storage and infestations. These are not technically complex or particularly expensive projects. But they are smarter and will improve food supplies in poor nations.

The global food crisis and rising fuel prices are inseparable. Our heavy reliance on energy is hurting the poor and plunging the vulnerable into poverty. We must change the way we use the planet's resources - all of our children will inherit the global food and energy crisis unless we lead now.