Background: Climate & Evolution
From Holocene to Anthropocene
The so-called conquest of nature overwhelms us with the natural fact of over-population and makes our troubles more or less unmanageable, because of our psychological incapacity to reach the necessary political agreements. It remains quite natural for men to quarrel and fight and struggle for superiority over one another. Where indeed have we "conquered nature"?
- C.G. Jung
Our planet is 4.5 billion years old. Its evolution has proved resilient enough to outlast enormously destructive crises that ended whole geological eras. We cannot, of course assume the same will be true for the biosphere we inherited in the current geological period.
Our human evolutionary lineage diverged from the chimpanzees line some six million years ago. The anatomically modern human species to which we belong is about 250,000 years old. These time-frames provide the back-story to all the scientific reports that now call for urgent protection of the planet's life support systems. [2,3] For although the planet may be able (on a timescale of a hundred million years) to do without us, there is no evidence that we can do without a very particular set of ecological conditions on Earth. The main determinant of those conditions is climate.
Regional climates on Earth vary greatly from its equator to its poles, because the parallel rays of the Sun fall unevenly across the curve of the planet's surface. Global average climate is the average of all those climatic regions. It showed little variation during the last 12,000 years, the Holocene epoch that gave rise to human civilization. The preceding 140,000 years of extreme climate variation did not allow humans to settle anywhere for long. We could lived only as hunter-gatherers.
Stable global climate permitted us to develop agriculture. With this came towns and cities and advanced cultures. By 2500 years ago, extraordinary developments had become possible. In Greece, masterpieces of classical art and philosophy appeared alongside the first democracy. In India, the prince Siddhartha Gautama renounced a kingdom to accomplish comprehensive self-realization.
The stable climate of the Holocene was maintained by a self-regulating atmosphere that finely balanced the concentrations of greenhouse gases (particularly carbon dioxide). These gases partially block the radiation of solar heat, from the planet back into space. Prior to the Industrial Revolution of the 19th century, the concentration of carbon dioxide in the Holocene atmosphere was 280 ppm (parts per million). Now it is 400 ppm.
The Earth entered a new geologic epoch when human industrial activity came to dominate the evolutionary path of the planet. Nobel Prize-winning scientist Paul Crutzen has called this unstable new period the Anthropocene era . By burning fossil fuels to power the industrial revolution we enormously increased carbon gas concentrations in the atmosphere. The 'forcing' of the greenhouse effect has increased global average temperature by 0.8°C since 1880. Momentous change is being felt across all climatic regions of the Earth. The polar ice caps and terrestrial glaciers are rapidly melting. Extreme weather events (hurricanes and typhoons, floods, heat waves and droughts) have quadrupled in frequency since the 1950s.
Eighty percent of global energy supply still comes from fossil fuels, creating an enormously powerful corporate sector that extracts and burns them for energy. We could usefully describe these entities as "Big Carbon". Oil, coal and gas generate the biggest profits in economic history, while rapidly running out and gravely damaging our planetary climate at the same time. Big Carbon is the incumbent / owner of the world's energy generation, distribution and infrastructure. As well ass enormous profits, it commands additional taxpayer subsidies of hundreds of billions of dollars a year. It wields enormous political influence through 'public relations' (ie. propaganda), advertising and direct corruption of political processes. Meanwhile our troubles become more or less unmanageable.
Media coverage of climate change and climate solutions is hopelessly inadequate. The media in general fail to support climate science or scientists, ignore the messenger and effectively kill the message. Their reinforcement of our addictive relationship with fossil fuels has encouraged many people to abandon reason for the 'belief' that climate change is an elaborate fabrication they can safely ignore. Man-made climate change, however, is a settled scientific fact. Like gravity, it does not go away because we refuse to 'believe' in it.
1. C. G. Jung Collected Works, vol 18.
2. UN Environment Programme
3. IPCC 4th Assessment Report
4. P. Crutzen & E. Stoermer Int Geo-Bio Prog News 41