Turning externalities to internalities… What does that mean?
Basically, right now we don’t pay the real cost of things we use – especially from the natural world. Think oil: the companies selling it set prices, but those prices don’t usually include the real cost to us and the planet – in terms of environmental pollution (harming humans and the environment), climate change, and the lost chance to ever use that oil for something else. That makes oil seem like it’s cheaper than it really is when you add up all the true costs.
So, an externality is something that impacts a lot of people and the planet, but isn’t internalized into the price. In the case of climate change, we’re talking negative externalities (there are also positive externalities, but they aren’t threatening our existence, so we’re not talking about them today).
The verb extin is a short-hand way of saying these negative externalities should be calculated in the price we pay for…ready for it?…ecosystem services. Ecosystem services are the good things the earth offers and does for us. Providing clean water and air, and fuels and other forms of energy. Bees pollinating the plants and trees so we have food to eat is a big one.
Let Wikipedia tell you more about it here.