Severe Consequences

Irrevocable Harm
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).

Destroying the Mechanisms of Survival
If maximum scale were exceeded then not only would ecosystem services be disrupted, but the very biophysical systems which produce these services would also be destroyed. To use a machine analogy, if maximum scale were exceeded we would not only lose the products made by the machine but we would also destroy the machine that makes the products. Furthermore, our ability to rebuild the machine would be lost.

Compounding Problems
Exceeding maximum scale is not the only serious threat. Exceeding sustainable scale is also dangerous. Whenever sustainable scale is exceeded ecosystem problems are compounded; the problems can spread from one global system to another, and fewer ecosystem services are available to meet human needs (see Ecosystem Functions & Services). Global biogeochemical cycles and ecosystems are by their nature complex and interconnected. They co-evolved over millions of years, intricately combining living and non-living systems. Disrupting any one of these major systems by exceeding sustainable scale will inevitably have profound effects on other global systems, potentially creating an escalating cascade of collapses.

The compounding of problems can occur in different ways. There is the impact of disruptions in one global system spreading to other systems. Current alteration of the carbon cycle through the emission of greenhouse gases, for example, is not only affecting global climate patterns. The climate changes are having an impact on the recovery of the atmospheric ozone layer, accelerating biodiversity loss, altering animal and human disease vectors, bleaching coral reefs, and generating more frequent and more intense storms. If these systems are themselves under stress from forces independent of the carbon cycle, as is the case, the magnitude of the disruptions will be enhanced. Under these circumstances the risk of pushing these other areas beyond sustainable scale is also increased.

Additional compounding may occur if human induced ecosystem disruptions trigger positive feedback mechanisms, enhancing the effect. Such occurences increase the likelihood that sustainable scale will be exceeded. If the northern permafrost is melted by global warming, for example, enormous amounts of methane stored in these frozen lands will be released. Methane is a powerful greenhouse gas and release of these reserves would contribute to yet more climate change (see Climate Change and Scale).

Unprecedented and Potentially Disasterous Impacts