The report alluded to the fact that putting a price on pollution, a price that is widespread and that's paid by most if not the totality of economic actors, has a cost, but it allows sectors to make the necessary trade-offs among themselves so that for those actors for whom it is the easiest to reduce emissions, they will do so. The report also says that there are other instruments available to economic actors—individuals, corporations, governments—to reduce emissions, regulations and subsidies being the two other broad categories of instruments, but these also have a cost, albeit the cost is often not as transparent as a carbon tax or a price on carbon.
That's what the report says. It also says that technological improvements can be a significant contributor to reducing greenhouse gases, but technological improvements are inherently hard to predict. If they were easy to predict, then some people would be very, very rich by investing in advance in these companies; some of them are indeed very rich and have that insight.
In a nutshell, that's essentially what the report says.