Holidays, for common people of modest means, often means feasting. There will be a lot of cook outs today in the USA, sometimes with families gathered from far flung locations (though less so than in the past), a lot of alcohol consumed, as well as fire and explosions. Good phun for some - beef, beer and bombs. A fair number of bullets will be fired as well, more for the explosive sound than anything else.

So, news of this World Bank report sharply contrasts with the mood of the day.

Biofuels have forced global food prices up by 75% - far more than previously estimated - according to a confidential World Bank report obtained by the Guardian.

The damning unpublished assessment is based on the most detailed analysis of the crisis so far, carried out by an internationally-respected economist at global financial body.

That doesn't mean that it is true, or makes even minimal sense, as we have seen so often when internationally-respected economists do reports. Politics pollutes everything.

The figure emphatically contradicts the US government's claims that plant-derived fuels contribute less than 3% to food-price rises. It will add to pressure on governments in Washington and across Europe, which have turned to plant-derived fuels to reduce emissions of greenhouse gases and reduce their dependence on imported oil.

Senior development sources believe the report, completed in April, has not been published to avoid embarrassing President George Bush.

Sources. Where would we be without politicized "sources" to feed the media monster and advance their political agendas? Surely it would be a better place.

The news comes at a critical point in the world's negotiations on biofuels policy. Leaders of the G8 industrialised countries meet next week in Hokkaido, Japan, where they will discuss the food crisis and come under intense lobbying from campaigners calling for a moratorium on the use of plant-derived fuels.

It will also put pressure on the British government, which is due to release its own report on the impact of biofuels, the Gallagher Report. . .

"Political leaders seem intent on suppressing and ignoring the strong evidence that biofuels are a major factor in recent food price rises," said Robert Bailey, policy adviser at Oxfam. "It is imperative that we have the full picture. While politicians concentrate on keeping industry lobbies happy, people in poor countries cannot afford enough to eat."

Political leaders are not leaders. They just respond to interest groups who provide them with money or other currencies, and so political power. It's useful to grasp this concept firmly when you are tempted to go all doe eyed about some politician's rhetoric. Biofuels were hyped to the skies by pseudo-environmentalists and green business. Political "leaders" didn't invent the ideas, they just went with the flow as greens exploited society. This is merely one instance among many.

Rising food prices have pushed 100m people worldwide below the poverty line, estimates the World Bank, and have sparked riots from Bangladesh to Egypt. Government ministers here have described higher food and fuel prices as "the first real economic crisis of globalisation".

President Bush has linked higher food prices to higher demand from India and China, but the leaked World Bank study disputes that: "Rapid income growth in developing countries has not led to large increases in global grain consumption and was not a major factor responsible for the large price increases."

Even successive droughts in Australia, calculates the report, have had a marginal impact. Instead, it argues that the EU and US drive for biofuels has had by far the biggest impact on food supply and prices.

This has been known and reported for a long time. Gary Becker, among others, has written about this in past months.

The report estimates that higher energy and fertiliser prices accounted for an increase of only 15%, while biofuels have been responsible for a 75% jump over that period.

It argues that production of biofuels has distorted food markets in three main ways. First, it has diverted grain away from food for fuel, with over a third of US corn now used to produce ethanol and about half of vegetable oils in the EU going towards the production of biodiesel. Second, farmers have been encouraged to set land aside for biofuel production. Third, it has sparked financial speculation in grains, driving prices up higher.

The claim that biofuels are responsible for 75% of the increase isn't reliable, others still dispute this, and isn't the important point. Even if food burning is only responsible for a third of the increase the fact remains that world food and energy supplies are being grossly distorted to the detriment of humanity for no more noble purpose than the enrichment of rent seekers and the aggrandizement of venal politicians. Note this well since there will be many more instances of harm due to green hysteria and environmental religion.

The next time you hear some outraged fool screeching that we must do something, take action about some issue that obsesses them, bear in mind that this is nearly always destructive. Useless flailing about poorly understood problems is wasteful and worse.