The straight answer is that it depends. Your question was which would be more stringent. One could set an emissions intensity target that is more stringent than a hard cap, or less stringent. It depends on what the target is. An emissions intensity target is set on the basis of emissions intensity. One could ratchet emissions intensity way down really quickly and achieve a more dramatic reduction than a very soft cap. On the other hand, a very strict, hard cap could produce significantly greater reductions than emissions intensity. It depends on the numbers.
On February 5th, 2007. See this statement in context.