The recession-induced reduction is like the Russian solution, where their economy collapsed and their emissions went way down. If you force a reduction in carbon dioxide that cannot be met by capital stock turnover in implementing more efficient equipment and new technology, then the only way of achieving such a reduction is to cut output. That's simple arithmetic.
The trick is to get a plan that is achievable, one that you can use to develop and deploy technology that will reduce emissions over time. But trying to go faster than you can, without being disruptive to your existing capital stock or trying to force things on consumers that they won't accept, actually slows you down.