Standard economists don't seem to understand exponential growth. Ecological economics recognizes that the economy, like any other subsystem on the planet, cannot grow forever. And if you think of an organism as an analogy, organisms grow for a period and then they stop growing. They can still continue to improve and develop, but without physically growing, because if organisms did that you'd end up with nine-billion-ton hamsters. There is a great video on this.

Robert Costanza in: "What is Ecological economics," at Yale Insights, May 2010.

What is ecological economics? | Yale Insights[insights.som.yale.edu]