The world's production of conventional hydrocarbons will soon decline. Hydrocarbon shortages are inevitable unless radical changes occur in demand, or in the supply of non-conventional hydrocarbons. The details are as follows: Global conventional oil supply is currently at political risk. This is because the sum of conventional oil production froth all countries in the world, except the five train Middle-East suppliers. is near the maximum set by physical resource limits. Should Middle-East suppliers decide to substantially curtail supply, the shortfall cannot be replaced by conventional oil from other sources. World conventional oil supply will soon be pit physical risk. The Middle-East countries have only little spare operational rapacity. and this will be increasingly called upon as oil production declines elsewhere. Large investments in Middle-East production, if they occur, could raise output, but only to a limited extent. (A partial exception is Iraq. but even here, there would be significant delays before prospects are confirmed and infrastructure is ill place.) If demand is maintained, and if large investments in Middle-East capacity are not made, the world will face the prospect of oil shortages in the near term. Even with large investments. resource limits will force Middle-East production to decline fairly soon, and hence also global conventional oil production. The date of this resource-limited global peak depends oil the size of Middle-East reserves, which Lire poorly known, and unreliably reported. Best estimates put the physical peak of global conventional oil production between 5 and 10 years from now. The world contains large quantities of non-conventional oil, land various oil substitutes. But the rapidity of the decline in the production of conventional oil makes it probable that these non-conventional sources cannot come on-stream feast enough to fully compensate. The result will be a sustained global oil shortage. For conventional gas. the world's original endowment is probably about the same, in energy terms. as its endowment of conventional oil. Since less gas has been used so far compared to oil, the world will turn increasingly to gas as oil declines. But the global peak in conventional gas production is already in sight. in perhaps 20 years. and hence the global peak of till hydrocarbons (oil plus gets) is likely to be in about 10 or so years.