The more pessimistic scenarios include many dystopian tales of human bioengineering gone wrong.

The plus to minus turnaround could be 5 million barrels per day in this pessimistic but realistic scenario.

Especially if the estimate that particular group is highlighted as the most pessimistic scenario?

But with oil prices hovering at $70 a barrel and the West showing signs of economic recovery, such pessimistic scenarios are unlikely.

The "pessimistic scenario" that he called unlikely in January is now playing itself out, he said.

Freeman Dyson found this a pessimistic scenario and so refused to consider it.

In a more pessimistic scenario, an emphasis on treatment leads to less effective implementation of prevention.

But before we let ourselves give way to this one-sidedly pessimistic scenario, let's examine further the problems facing us, and their complexities.

The bank stress tests have just concluded, based on the most pessimistic scenarios in Ireland.

It's not going to be quite as bad as some of the more pessimistic scenarios had suggested.