• Energy use per person
   
  
• Annual emissions of greenhouse gases per person
   
  
• Percent of land area that is natural, modified, cultivated, built, and degraded

• Use of material resources
   
  
• Use of ecosystem services like CO2 uptake
   
  
• Use of land resources for different purposes

Some of the indicators that are proposed in "Caring for the Earth" include the amount of energy used per person, the amount of greenhouse gases produced, or the amount of land used for different purposes. Note that these indicators do not just look at the flow of money, they look at the flow of resources and the use of services that the earth provides, like CO2 uptake. They also recognize that land is a finite resource that is needed for many different purposes.