Sustainable scale problems differ from many other environmental problems in significant ways. Most critical is that sustainable scale problems have the potential for irrevocable harm to vital life support systems, such as climate stability, UV radiation protection, and the resilience provided by biodiversity. In the past, environmental problems were local, and the harms done were largely reversible. However, if maximum scale is ever exceeded then the harm done will be irrevocable, the losses will be permanent, and there will be no substitutes for the services lost. Even if this worse case scenario is avoided we run a double risk if we exceed sustainable scale. Firstly, the ecosystems services we rely on are reduced in both quantity and quality. Secondly, these reduced services mean we are more vulnerable to exceeding maximum scale as time passes (see Unsustainable Scale for a description of these types of scale).