CLIMATE BYTES

By Rudy Rogalsky

This is another in  a series of short notes about aspects of the climate crisis. 

VARIATIONS ON A THEME

Here, we consider three frameworks for understanding the dynamics of the earth’s environmental systems. Each one embodies the notion of limits. Each one points toward potential danger. 

The first, Earth Energy Imbalance (EEI), is the difference between the amount of energy hitting the earth from the Sun and the energy radiated back to outer space by the Earth. If EEI  is positive, the earth warms and, as it warms, more out-bound infra-red radiation is generated. Just as a hot cup of coffee radiates warmth until it cools to room temperature, if there are no other outside influences, earth’s energy out-flow will continue until EEI is once more in balance. In the 11,000 yea pre-industrial Holocene era, energy-in and energy-out were in balance which explains why the earth’s temperature varied little from 14^o C. With industrialization came burning of fossil fuels and increase in C0₂ concentration in the atmosphere from about 280 ppm to 420 ppm. Some of the energy from outgoing infra-red radiation began to be absorbed by CO₂ in the atmosphere causing imbalance in earth energy flows. Humans used the abundant hydrocarbon energy to overcome Malthusian constraints, to expand population numbers, and to create hitherto unprecedented per capita prosperity. Hansen argues that, in doing so, our ancestors made an implicit Faustian bargain and, now, the first reality payments on that deal with the devil are coming due. 

A second environmental dynamics framework is Ecological Footprint Analysis which was developed by Prof. William Rees and one of his students at UBC. This form of analysis derives directly from ecological economics which, unlike conventional economics, treats the human economy as a fully dependent sub-system of the natural environment. [Wackernagel/Rees, Our Ecological Footprint, 1996] 

Footprint Analysis focuses directly on measuring the supply of and human demand for Nature’s services. During the 11 thousand years before 1970, the small human population made demands for Nature’s beneficence which were much less than Nature’s capacity to provide. Then, as noted above, fossil fuel energy-use facilitated the exponential growth of human population and consumption per capita and demands on Nature. After 1970, global ecological footprint of humanity began to exceed Nature’s sustainable yield, human culture has been fixated on furthering economic growth. Through such excesses as over-fishing and degradation of top soil, we now need the equivalent of three-quarters of a second sustainably-run earth to meet our demands. 

Dr. Rees asserts that this “overshoot” will eventually result in ecosystem collapse and, with that, the potential demise of the human economy. While the world is, quite rightly, focused on global warming, he sees overshoot as the primary environmental problem. Within that, climate change and the CO₂ emissions causing it, are fundamentally a critically important waste management problem.

In yet another framework, Climate scientists led by Johan Rockström [see many Youtube lectures by him] have defined overshoot in terms of Planetary Boundaries. They have identified 9 processes that, individually and interactively, threaten the stability of the entire Earth system. For each of those processes they have been able to map a boundary between a safe operating space for humanity and the operating space where human actions have unknown and potentially catastrophic results. That safe operating space is derived from what is known about conditions in the goldilocks Holocene Epoch prior to the industrial revolution.

There are nine earth processes for which boundaries have been mapped. Using more descriptive terminology than is in the published material, the critical processes are: 1) Climate Change; 2) Biosphere Integrity; 3) Over-usage of Nitrogen and Phosphorous; 4) Pervasiveness of novel products such as plastics; 5) Conversion of land for agriculture and urbanization; 6) Over-use of ground water and running water for irrigation and urban uses; 7) Ocean acidification caused by CO₂ absorption; 8) Air pollution; 9) Stratospheric Ozone Depletion. 

Each of the processes are classified as to whether it is functioning in a safe operating space, a zone of increasing risk, or in a high-risk zone. High-risk means that a process is approaching a possible tipping point when the negative effects can become self-perpetuating. Of the nine, the two most critical for maintaining earth system integrity are Biosphere Integrity and Climate Change. Both are in the high-risk zone as is the over-use of nitrogen and phosphorous. Still precariously functioning in  the safe operating space are ocean acidification, atmospheric pollution and, the success story, stratospheric ozone depletion, which once was a high-risk process. The other 3 processes are outside the safe operating space and are on a trajectory of increasing risk. That risk is that at sometime in the unknown future a process may take on a life of its own and become self perpetuating with no turning back.

All three of the above frameworks point to a world that is clearly operating beyond limits of safety. Voluntarily or inevitably, all frameworks say we can’t continue our fixation with growth and we need to turn back our operative clock to a simpler but still prosperous time.