When you look at the Global Greenhouse gas problem, what happens in the developing world really matters. Switching from coal to natural gas over the next couple of decades is something we can do quickly and basically cut emissions, you know, buy about a factor of two. And it would be wonderful to see us get off of coal as quickly as possible. So the conversion from coal to natural gas is a relatively easy thing to do and is already happening big time in the United States. And the potential is for countries like China, for example, you know, to stop using so much coal, to stop increasing the amount of coal they're using, switch to natural gas. The natural gas revolution gets its name from two related factors. One is the ability, using horizontal drilling and multi-stage hydraulic fracturing, fracturing every horizontal well multiple times, to extract gas from what are the traditional source rocks for all hydrocarbons. These are called chale formations. So this cheap and abundant natural gas has been quite remarkable resource. Now that doesn't mean there aren't problems and there are plenty of problems. Hydraulic fracturing is really not the origin of the problems. The origin of most of the problems we have is due to poor well construction. The toxic chemical part of it is actually when you finish hydraulic fracturing and you flow the water back out of the shell. You want to get the water out of the way so the gas can flow. The water that comes back picks up a lot of salt and things like salineum and arsenic and iron. The water that comes back then has to be dealt with. You can't discharge it at the surface, you have to dispose of it properly. Natural gas is not a perfect fuel. I mean it produces CO2. If methane leakage occurs, methane is a potent greenhouse gas. But it's a far superior tool to coal. The amount of gas available to the global community is just enormous. We talk about hundreds of years of natural gas. Now of course we don't want to use natural gas for hundreds of years. We want to decarbonize our energy system. But it's certainly an energy source that we can use as we transition from a fossil fuel based energy system to a non fossil fuel based system. It's very important that as we switch to natural gas away from coal as we provide more energy for the world's growing population and provide more energy for a population that's getting richer and needing more energy, that we do so by doing less harm than we've done in the past. But at the same time we can't lose sight of the need to decarbonize the energy system over the next, say half century. And so fear of being complacent, of being locked into the investments made with pipelines and facilities for natural gas. It's a real fear and it's a justified fear. The other fear of committing to natural gas is that it would be a disincentive to invest in renewables. And renewables are far better than natural gas. So we need more wind, we need more solar, but we're no longer burning wood, we're no longer burning peat. Energy systems have evolved and they've evolved to cleaner and more efficient energy systems since the dawn of man. And switching from coal to natural gas is just part of that process and switching from natural gas to decarbonized energy sources is our future.