Depletion of Fossil Fuels(矿物燃料的耗竭）

A number of(许多） scientists are emphasizing（强调） the tremendous challenges that will soon be faced when the depletion of fossil fuel supplies coincides with an alarming increase in the global population.（当化石燃料供应的枯竭与全球人口的惊人增长同时发生时，将很快面临巨大的挑战。）

They highlight agriculture which is heavily dependent not only on gasoline to fuel machinery, but also on the petrochemicals(石油化工产品） necessary to manufacture（制造） synthetic fertilizers（化学肥料） and pesticides.(他们强调，农业不仅严重依赖汽油作为机械燃料，而且严重依赖制造合成肥料和杀虫剂所必需的石化产品)

Without these petrochemicals, crop yields(粮食产量） would be only a fraction of （一小部分）what they are today. To assume(假定） that an abundant source of renewable（可再生） energy will address（应对） this challenge is to ignore that vital non-fuel uses of petrochemicals.石油化工产品的重要非燃料用途

Then there is the challenge posed to the current levels of mobility此外，目前的流动性水平也面临挑战. As a fuel, gasoline is unrivalled（无与伦比的） in its portability（便携性）.Electricity requires bulky(笨重的） batteries and hydrogen is notoriously difficult to store.（氢储存是出了名的困难）Biofuels might seem like an alternative, but the energy consumed（消耗） when converting corn into bioethanol(生物乙醇）, for instance, greatly exceeds the output(大大超过产量） when the fuel is utilized(利用).  In any case(无论如何）, once we reach a crisis in the food supply（我们一旦粮食供应出现危机）, it will not make sense to divert food crops to other users.

Although there seems to be a widespread belief that the era of oil dependency(石油依赖时代） is coming to an end due to some technological remedy, this may be mistaken. Relying on such an assumption(假设） can lead to complacency（自满） and a failure to take precautions（预防措施）. Experts may not be able to come up with the kind of solution that can lead to（实现） a pain-free transition（过渡). Scientists warn that relying on alternative resources might only support half of the global population. The absence of a realistic alternative to fossil fuels will mean that the first priority will be to curb(控制） the demand for food.缺乏一种切实可行的化石燃料替代品将意味着，首要任务将是抑制对粮食的需求。