Sustainable development is defined as development that meets the needs of the present without compromising the ability of future generations to meet their own needs. Because it balances three pillars — economic, social and environmental — the indicators used to track it must capture more than just money. A good sustainability indicator reflects human well-being and the health of natural systems together.

The following are genuine sustainability indicators:

• Human Development Index (HDI) — a composite of life expectancy (health), education, and per-capita income, so it measures well-being rather than raw output.
• Ecological Footprint — the area of biologically productive land and sea needed to supply what a population consumes and to absorb its waste; it measures human demand on nature.
• Biocapacity — the capacity of ecosystems to regenerate resources and absorb waste; comparing it against the Ecological Footprint shows whether a population is living within nature's limits.

The GDP growth rate is the correct answer as the exception. GDP measures only the market value of goods and services produced, and its growth says nothing about how that growth was achieved. An economy can post high GDP growth while depleting forests, polluting rivers, widening inequality, and exhausting non-renewable resources — costs that GDP does not subtract. It also ignores unpaid work and the distribution of income. For these reasons GDP growth is a measure of economic activity, not of sustainability, unlike HDI, Ecological Footprint and Biocapacity, which each directly track well-being or environmental limits.