Human beings are pretty damn clever. We have adapted and invented our way out of some extremely grim situations. And we can do the same in the face of climate change! The ideas and innovations necessary to ensure our security, and the security of future generations, are within our power. What's needed is a smooth, effective conveyor belt to carry those ideas and innovations from our heads, into the world, and up to sufficient scale.
Unfortunately, as things now stand, that conveyor belt is rusty and full of gaps. Clever ideas get stuck in our heads, or fail to make it across the "valley of death" between labs and markets, or fail to take hold and grow in those markets. We call these gaps "market failures," but that is a misleadingly passive construction. The conveyor belt is not something that exists in Platonic market space, a priori, that we merely need to uncover. It is something we must build, consciously, using markets among other tools.
Tastes great vs. less filling
For many years, climate hawks have been engaged in misguided and self-defeating debates about which end of the conveyor belt to fix. On one side are those who want to fix the early end, where ideas move from imagination to lab to early market. These folks talk a lot about innovation and are criticized (somewhat unfairly) as denying the need for deployment.
On the other side are those who want to fix the later end, where ideas move from early market to large, world-changing scale. These folks talk a lot about deployment and are criticized (somewhat unfairly) as denying the need for innovation.
Both sides accuse the other of failing to grasp the threat of climate change.
The innovation side accuses the deployment side of misunderstanding the scale of the problem. There is so much energy poverty remaining in the world, so many people in the developing world rising toward the middle class, such massive demand, that we can't hope to satisfy this century's energy (or agricultural, water, transportation ...) needs with today's technologies.
The deployment side accuses the innovation side of misunderstanding the urgency of the problem. If we are to stay within our carbon budget for the century, global emissions must peak and begin falling (quickly) within five years or so. To have a real chance at preventing catastrophe, we ideally ought to drive carbon emissions to zero, or even negative, well before the end of the century. There is simply no way to do that unless we rapidly deploy the technology we have today. Even if a technology breakthrough appeared in a lab tomorrow, there simply isn't enough time to drive it past all the market barriers to wide adoption fast enough to forestall disaster.
So, who is right? Well, they are both right, about everything except the fact that the other is wrong.
So why fight at all? Here it's worth briefly pondering the history of the debate.