Climate change: Red alert in the Anthropocene

It is fitting that “Anthropocene”, the term coined just more than ten years ago by Paul Crutzen, a Nobel Prize-winning atmospheric chemist, denotes the new ecological period, following the end of the Holocene, when humans became the principal force driving changes in the planetary system. I say this because the Holocene (“New Whole”), or stable geological period of about 12 000 years between ice ages, came to an end around the Industrial Revolution of the late 1700s, which is exactly the time when humans moved into the position where they are capable of affecting life on earth as we know it. Unfortunately the Anthropocene may turn out, if scientists working in the area of the geo-sciences are correct in their assessment of what are now called “planetary boundaries”, to be a mere flicker in terms of geological time.

James Hansen, regarded as the leading climatologist in the US, explains the reason for this bleak prospect in his book, Storms of My Grandchildren (2009): “Planet Earth, creation, the world in which civilisation developed, the world with climate patterns that we know and stable shorelines, is in imminent peril. The urgency of the situation crystallised only in the past few years. We now have clear evidence of the crisis … the startling conclusion is that continued exploitation of all fossil fuels on Earth threatens not only the other millions of species on the planet but also the survival of humanity itself — and the timetable is shorter than we thought.”

In The Ecological Rift — Capitalism’s War on the Earth (p13), John Bellamy Foster and his co-authors remind one that most people think of the ecological crisis today almost exclusively as climate change, which is prominent in the news because it poses virtually insurmountable problems for capitalism. In fact, however, climate change is but one of nine “planetary boundaries” that have been scrutinised by natural scientists in recent years. These are decisive for sustaining a biosphere in which humans can exist securely. The other eight are chemical pollution, biodiversity loss, change in land use, global freshwater use, stratospheric ozone depletion, atmospheric aerosol loading, the phosphorus and nitrogen cycles, and ocean acidification. Although two of these — chemical pollution and atmospheric aerosol loading — still lack reliable physical measurements, distinct boundaries have been established for the other seven.

These planetary boundaries are subject to on-going global processes, and scientists at the Stockholm Resilience Centre have found that three of them have already crossed their respective boundaries, namely climate change, biodiversity loss and the nitrogen cycle, all of which can therefore be regarded as representing a “rift”. Although stratospheric ozone depletion threatened to become such a rift in the 1990s, it has been stabilising of late, but global freshwater use, ocean acidification and the phosphorus cycle are fast approaching rift status. Moreover, ocean acidification, climate change and stratospheric ozone loss are seen as “tipping points”, which would be capable of destabilising the earth system (when certain levels are reached) by introducing sweeping qualitative changes. The boundaries for the other four processes are viewed, not so much as “tipping points”, but rather as points at which irreversible environmental degradation would set in.

When confronted by such stark, ominous-sounding statements in texts written by reputable scientists, one can easily feel overwhelmed, or sceptical, depending on one’s knowledge of the way such scientific claims are established. To begin with, sceptics should be reminded that scientists worldwide are largely in agreement about these findings today, and secondly, that it is for good reason. While the precise sequential manifestation of irreversible environmental degradation cannot be delineated because of the complexity involved, however, there are a number of things that can, and have been, reasonably precisely ascertained through careful measurement and modelling. Johan Rockström and his associates in Stockholm (including Crutzen and Hanson) have established three values for each of the seven (measureable) “boundary processes” referred to above, namely a pre-industrial value (or levels reached before the beginning of industrial capitalism), a boundary level value, and a current level status value.

For example, the pre-industrial value of climate change was 280 parts per million (ppm) carbon dioxide atmospheric concentration. The boundary proposed for this is 350 ppm, beyond which it should not go if the tipping point of events such as catastrophic sea level rise were to be prevented. Its current status is already 390 ppm, which means it is well beyond the tipping point. The loss in biodiversity is measured by extinction rate, or the number of species lost per million species annually. The preindustrial, or “natural” rate was 0.1-1 per million; the estimated boundary is 10 per million per year, and the current rate of species loss is above 100 per million annually (almost 1000 times the preindustrial “natural” rate). The third process that has crossed its boundary level, the nitrogen cycle, concerns the number of tons (in millions) of nitrogen removed from the atmosphere for industrial use per year. Before the discovery of the Haber-Bosch process for such removal in the early 1900s, the amount taken from the atmosphere was 0 tons. The estimated annual boundary for avoiding irreversible deterioration of the planetary system is 35 million tons, and at present the amount removed per year is 121 tons.

These are only the figures for the three boundary processes that are already at extreme levels — what one should keep in mind, is that all these processes, or rather, all their effects in nature, are interconnected in almost incalculably complex ways, and scientists can only prognosticate to a certain degree what might result from the extreme conditions that already obtain. As Foster and his fellow authors state, however (p15), “In each of these extreme rifts, the stability of the earth system as we know it is being endangered. We are at red alert status. If business as usual continues, the world is headed within the next few decades for major tipping points along with irreversible environmental degradation, threatening much of humanity. Biodiversity loss at current and projected rates could result in the loss of upward of a third of all living species this century”. Add to this the well-known interconnectedness of living species in terms of food-dependence (the “food chain”), which has incalculable consequences when species are removed from this interlinked network of life, and it hardly takes a genius to understand that the world as we know it may undergo not-so-pleasant mutations in the not too distant future.

Humanity must — absolutely MUST — change its way of living urgently. It must find alternatives to an economic system that takes more out of the earth system than it can put back. It must learn to live within the boundaries identified by these scientists — boundaries that other scientists can, and have, tested. The science is clear; the future is not.