And that brought me then to climate justice. Climate justice responds to the moral argument -- both sides of the moral argument -- to address climate change. First of all, to be on the side of those who are suffering most and are most effected. And secondly, to make sure that they're not left behind again, when we start to move and start to address climate change with climate action, as we are doing.
In our very unequal world today, it's very striking how many people are left behind. In our world of 7.2 billion people, about 3 billion are left behind. 1.3 billion don't have access to electricity, and they light their homes with kerosene and candles, both of which are dangerous. And in fact they spend a lot of their tiny income on that form of lighting. 2.6 billion people cook on open fires -- on coal, wood and animal dung. And this causes about 4 million deaths a year from indoor smoke inhalation, and of course, most of those who die are women. So we have a very unequal world, and we need to change from "business as usual." And we shouldn't underestimate the scale and the transformative nature of the change which will be needed, because we have to go to zero carbon emissions by about 2050, if we're going to stay below two degrees Celsius of warming. And that means we have to leave about two-thirds of the known resources of fossil fuels in the ground.