Earth System Complexities

In an earlier post I tried to simplify the IPCC findings on climate change. There still remains a lot of complexity and poorly understood feedback loops within the world system. Can that too be boiled down?

The graphic above gives some sense of the complexity of the known feedback loops within the earth system. Basically, the physical climate system would be in equilibrium without external forcings. So anthropogenic (human) forcings (in addition to other forcings such as incoming solar insolation, meteor strikes and volcanic eruptions) send the system in to disequilibrium.

The simplified graphic above, focusing just on disequilibrium, shows that there are still two somewhat unpleasant feedback loops the will return the Earth system to equilibrium. If climate change has a negative impact on human activity (such as flooding of the Mekong Delta as a result of rising sea levels), it will reduce land-use and CO2 forcings.

To avoid unpleasant Malthusian checks on human activity, we have the policy options (+/-) of reducing our land use patterns and reducing our CO2 emissions ("Feedback Loops in the Earth System" was the topic of today's "Global Warming Debate"). The simplified graphics is, I think, as simple as it can be put while still retaining the systemic aspects of the problem (Earth scientists would certainly disagree). Future posts will discuss some of the proposed policy solutions.