The population of the world needs to decrease substantially. I'm talking by hundreds of millions and even billions. I know lots of first world people who care about the environment. They drive cars, fly in planes, buy iPhones, buy computers, buy large amounts of plastic wrapped food items. But they care!

As poverty declines hundreds of millions of more people join the ranks of super consumers. The environment can't sustain the damage done to satiate the current level of consumption. Fewer people is what is needed.