What are earth system thresholds that are sensitive to biotic impoverishment?

Through the predominant period of the rise of humanity as the dominant species (the Holocene), earth system properties have been relatively benign with respect to the constraints within which the current biosphere remains viable. We are distracted by climate change to the point that Heinrich events, Dansgaard-Oeschger events, and the Bølling-Allerød transition draw us away from the more basic scientific issue as to why climate remains largely within boundary conditions conducive to life on Earth. It is also possible that the question of global biotic thresholds is mistakenly assumed to be some form of Gaia-Hypothesis like thinking, a topic which has some strong supporters, but is largely unpopular among many scientists. Because there is likely to be an immense suffering in the face of climate change, it would be inappropriate to suggest that such questions should not dominate our attention – they deserve substantial, immediate attention. Climate change research, however, in its current form, incorporates enormous “black boxes” and this is not the best science. GCM models tax even the best super computers, but until such models contain hundreds of ecosystem types, each made up of hundreds of functional species types, and contain key interactions among species and their environment, we are avoiding the true challenge before us – to understand Earth systems in its entirety – physical, chemical, and biological with spatial and temporal accuracy all coupled to social systems.

The Millennium Assessment achieved an unprecedented consensus among natural and social scientists from around the world declaring that the most pervasive environmental problems we face are caused by the massive spending down of natural capital – our biodiversity and our natural resources. Thirty years ago no one might have imagined we would have multi-million dollar, international efforts and intergovernmental panels seeking to understand the global carbon cycle and its relationship to climate using the most advanced research methods and techniques ever developed. Yet, the scientific foundation for this endeavor can be traced back to Arrhenius in 1896. To wait a similar period to build upon the Millennium Assessment’s findings would leave us facing problems in the future that were readily addressed today.

Given rates of local and global extinction, tt is difficult to imagine any challenge greater and more urgent than identifying earth system thresholds sensitive to biotic impoverishment.