Depletion(耗减 缺乏 贫化 of Fossil Fuels

A number of scientists are emphasizing the tremendous challenges that will soon be faced when the depletion of fossil fuel supplies coincides with an alarming increase in the global population. They highlight agriculture which is heavily dependent not only on gasoline to fuel machinery, but also on the petrochemicals necessary to manufacture synthetic(人工合成的) fertilizers and pesticides.  Without these petrochemicals(石油化学产品), crop yields would be only a fraction of what they are today. To assume that an abundant source of renewable(可再生的) energy will address this challenge is to ignore the vita(必不可少的)l non-fuel uses of petrochemicals. 

Then there is the challenge posed to the current levels of mobility. As a fuel, gasoline is unrivalled(无与伦比的) in its portability(轻便). Electricity requires bulky batteries and hydrogen is notoriously difficult to store. Biofuels might seem like an alternative, but the energy consumed when converting corn in to bioethanol( 生物乙醇 ), for instance, greatly exceeds the output when the fuel is utilized(使用利用). In any case, once we reach a crisis in the food supply, it will not make sense to divert food crops to other use.

Although there seems to be a widespread belief that the era of oil dependency is coming to an end due to some technological remedy(处理方法，改进措施), this may be mistaken. Relying on such an assumption 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 a pain-free transition(过度转变). Scientist warn that relying on alternative resources might only support half o the global population. The absence of a realistic alternative to fossil fuels will mean that the first priority will be to curb the demand for food.

1. The article implies that the general population...

---Assumes that things will get better.

2. According to this article, current alternative to gasoline...

---are much less convenient.

3. To be unrivalled means... to be better than any competitors.

4. To adress a problem means... to deal with it.

Relying on such an assumption can lead to complacency(自满) and a failure to take precautions(预防措施). 

Without a realistic alternative  to fossils fuels, food supplies may not be enough.

The aim of the article is to highlight the seriousness of the situation.

Agriculture is heavily dependent on gasoline to fuel machinery.

Scientists warn that relying on alternative resources  may cause food shortages.