 Okay, so first of all, imagine that we found a way to stabilize population at a significantly lower level. Through appropriate governmental policies, we found a way to limit global population to 10 billion rather than 11 billion. How does that change things? Well, we can see. We've lowered our carbon emissions, our projected carbon emissions. The CO2 concentration at 2100 is now a little bit above 650 parts per million, so we've knocked off about 50 parts per million of our projected CO2 increase by 2100. Would be very difficult to decrease the projected global population much more than that, but let's say we go for 9 billion, then we've now lowered the 2100 CO2 concentration to below 650 parts per million. So we're slowly working our way towards 550 stabilization. Let's imagine that we were able to increase energy efficiency more than is currently projected through new technologies that have not yet been incorporated or implemented, perhaps some large scale use of fusion energy. So let's imagine that the energy intensity, that we can get a better improvement in energy intensity. We're closer to 1.5% decline versus a 1% decline in the amount of energy that we need per unit dollar. Well, now we have lowered CO2 concentrations even more. We're a little bit above 550 parts per million. Now of course, if we were to establish policies that favored non-carbon based forms of energy, renewable energy, technology, then we can of course further improve our carbon efficiency, and so we might imagine changing this number from minus 0.3% to maybe minus 0.6% or so. If through the introduction of appropriate policies. And now we have come very close to a 550 ppm stabilization. So we would have to go in and look more in more detail at the assumptions that go into assuming that we can change carbon efficiency by the amount that we've changed it or that we can change energy intensity by the amount that we've changed it. If we, for example, look at how we now are comparing with the historical trajectories, we can see that our energy intensity curve is far more optimistic than would be suggested by even the past two decades, which we originally used to extrapolate the future trend somewhat optimistically. If we look at carbon efficiency, then to decrease our reliance on carbon based energy by the amount assumed in the carbon efficiency number we've used, again, we would need to start doing significantly better in terms of that decline in use of carbon based energy than we have done in even the past decade or two. So clearly changes in policy, changes in behavior, somewhat dramatic changes in policy and behavior would be necessary to put us on the trajectories that are in essence dependent on these optimistic numbers we've now used to replace the so-called business as usual settings in our attempt to lower future CO2 emissions and future CO2 concentrations. We can see, for example, that to follow this 550 ppm, we've come pretty close now to 550 ppm stabilization. We're a little bit above the 550 ppm stabilization, but not too far above.