As a country increases its investments more and more complex stages of production are added to its capital structure. The faster the structure expands, the faster real incomes grow. This is the process that generates wealth and raises real incomes. It's also called economic growth. The idea that capital accumulation is not sustainable is another piece of green propaganda.
Capital accumulation can continue indefinitely so long as sufficient savings are made available.
It should be made clear, though it rarely is, that capital accumulation does not mean the simple multiplication of existing capital goods. As the Austrians school of economics has continually stressed, the capital structure expands by lengthening its structure. This is brought about by adding lengthier and more productive stages to the structure, a process that the market coordinates. These stages contain capital goods embodying the technical knowledge that raises Labor's output. Townsend would evidently answer that finite resources would terminate this process.