by Roy Wilkes
Greenhouse gas emissions are arguably the most dangerous by-product of capitalist accumulation. They constitute a cancer which is attacking the vital organs of our ecosystem. And like the most dangerous of cancers, its full impact will not become apparent until after it is too late. There are two reasons for this: time lag effects and feedback effects.
There is a time lag because water has a greater heat capacity than air. The oceans are a huge heat sink and have taken up 84% of the excess heat due to human made greenhouse gas emissions. It takes time to heat the oceans to their full depth. So, even after we have stabilised the level of greenhouse gases in the atmosphere, we can expect a further 0.6 degrees of warming, which is as much as we have experienced since 1860.
But feedback deliver the real sting in the tail. We can identify a number of key feedback effects: a reduction in the reflectivity of the earth’s surface (albedo) as a result of the melting of ice sheets; increased water vapour in the atmosphere due to higher rates of evaporation; the release of huge quantities of methane from the melting of permafrost and of methane clathrates from the ocean beds; and the loss of other natural carbon sinks, such as the Amazon rainforest and the Borneo peat swamps.
The albedo effect was evident during the last ice age. As ice sheets expanded to cover a third of the Northern Hemisphere, the amount of sunlight reflected by the white surface back into space increased from 30% to 33%. This was enough to reduce the solar heating of the Earth’s surface by an average of 4 watts per square metre. However, the converse will also be true. As the ice sheets melt, less sunlight will be reflected and solar heating of the Earth’s surface will increase. Veerabhadran Ramanathan of the Scripps Institution of Oceanography suggests that if the planet’s albedo dropped by just a tenth from today’s level, the effect would be comparable to a fivefold increase in atmospheric concentrations of carbon dioxide.
Warming also increases the rate of evaporation from the oceans, which raises the amount of water vapour (itself a greenhouse gas) in the atmosphere. This may to a certain extent be mitigated by cloud formation, since clouds (like ice sheets) have an albedo effect (although at night time they contribute to heat retention, by blanketing the planet.) However, warming may also change the nature of clouds, reducing the number of fluffy cumulus clouds and replacing them with dark cumulo-nimbus clouds that rain out quickly, leaving behind them clear blue skies.
Even more worrying than a reduction in albedo is the feedback effect of methane. Tens of billions of tons of carbon lie frozen in the West Siberian peat bogs, and these are already starting to melt. As the peat degrades and rots, carbon will be released as methane, which is up to a hundred times more potent as a greenhouse gas than carbon dioxide. Larger quantities of methane lie frozen into water “cages” in the sediment just beneath the ocean bed. As ocean temperatures rise, the risk of circulating currents bringing these clathrates to the surface, where they decompose and release methane into the atmosphere, increases.
When ocean clathrates melt, they do so explosively, bringing with them the risk not only of sudden, abrupt and unstoppable climate change, but also of devastating fire storms — a truly hellish prospect. A vast surge of methane from the oceans 55 million years ago pushed average temperatures up by 5 degrees C. Methane only remains in the atmosphere for a hundred years or so, since it degrades into carbon dioxide — but by then the damage is done.There are also negative feedbacks, which help to maintain climate stability. Aerosols (particles of soot, smoke, smog and dust) given off by burning coal, crop stubble and wood, tend to reflect or absorb solar radiation. Ironically, measures taken to reduce smog emissions for perfectly good public health reasons may lead to a sudden burst of warming. Another negative feedback arises because warmer atmospheres produce more, and heavier, rain, which dissolves carbon dioxide to form carbonic acid. Although this is devastating to ocean ecosystems, it does remove some carbon dioxide from the atmosphere.
Climate-change sceptics also suggest that higher concentrations of carbon dioxide are conducive to more vigorous plant growth. While this might be true under natural conditions, the shear mass of carbon dioxide that industrial capitalism is pumping into the atmosphere, combined with the unprecedented rate of deforestation, are overwhelming these stabilising factors. In other words, the negative feedbacks might be buying us a little time, but at the cost of greater instability in the long run. Unless we drastically reduce carbon emissions very quickly, the positive feedbacks will undoubtedly win out in the end.
The overall effect of these feedbacks will be to turn our biosphere from a net carbon sink into a huge carbon source. Peter Cox, of the UK Centre for Hydrology and Ecology, calculates that by the end of the century, the biosphere could be adding 7 billion tonnes of carbon to the atmosphere each year (roughly equivalent to the world’s current output from burning fossil fuels.)
The temperature rise over the past century, taken as a global average, represents a unique departure from the relative stability of the previous two millennia. (Even the mediaeval warm period and the “Little Ice Age” were Northern Hemisphere events which were balanced by opposite conditions in the southern hemisphere.) Michael Mann, director of Earth System Science Centre, Penn State University, depicts this as a graph in the shape of a hockey stick — flat for a long period and then rapidly increasing.
But feedbacks will greatly amplify this already observable trend, so that instead of continuing to rise in a steady and predictable way, a “tipping point” will eventually be reached, beyond which temperatures will shoot up suddenly and dramatically, bringing in their wake unpredictable chaos to both climate systems and the ecosystems which rely upon them. Jim Hansen, director of NASA’s Goddard Institute for Space Studies, puts it like this: “We are on the precipice of climate system tipping points, beyond which there is no redemption.”
The processes unfolding in our climate system give us a striking example of the materialist dialectic, which holds that at a certain stage in the gradual accumulation of quantitative changes, a qualitative leap occurs, a great break with the past. In Dialectics of Nature, Engels explains that “Dialectics offers the method of explaining the evolutionary processes occurring in nature, inter-connections in general, and transitions from one field of investigation to another.” He identifies three fundamental laws of dialectics: the transformation of quality into quantity and vice versa; the interpenetration of opposites; and the negation of the negation. Engels illustrates these laws with reference to the scientific theories that were current at the time.
Subsequent developments in science have confirmed the essential truth of the dialectic. One of the most dramatic was the discovery that the energy of electrons surrounding an atomic nucleus does not increase continuously but in discrete quanta (hence the development of quantum mechanics.) The materialist dialectic is also evident, and particularly relevant to our investigation, in the historic cycle of ice ages.
Over the past 2 million years, the climate system has regularly switched between two stable states: glaciated (ice ages) and inter-glacial (temperate periods), with the change-over occurring roughly every 100 000 years. The primary cause of this switch is the eccentricity of the Earth’s elliptical orbit around the Sun (moderated or amplified in between times by other factors such as precession). The variation in eccentricity, which is caused by the gravitational pull of other planets in the solar system, varies according to a 100 000 year cycle, which corresponds directly to the cycle of ice ages. When the Northern Hemisphere (which contains most of the land mass) experiences its coolest summers, there is insufficient energy to melt the ice that has built up during the preceding winter months, and an ice age ensues.
But the climate doesn’t change gradually from one state to another, (even though the change in eccentricity is itself gradual,) and there is no in-between state; instead, stability is maintained in one state for tens of thousands of years until suddenly the system flips over, with the transformation occurring within at most a couple of hundred years. Once again we see the materialist dialectic confirmed: gradual changes build up within the existing climate state until some tipping point is reached; quantity is transformed into quality and glaciation either suddenly advances or retreats.
During the final millennia of a glacial period, for example, negative feedbacks maintain the stability of the ice age while the warming factors are gradually building up within the system (the interpenetration of opposites). Eventually the negative feedbacks are themselves negated, positive feedbacks take hold and the system flips over to the interglacial state (negation of the negation). And of course the process is reversed at the end of an interglacial period.
The ice ages were characterized by an atmosphere containing roughly 400 billion tonnes of carbon. During the interglacial states the atmosphere held about 600 billion tonnes. During the period of transition from one state to another, atmospheric carbon levels rise or fall rapidly then stabilize at the new level. One of the most worrying features of the current situation is that atmospheric carbon is already approaching the 800 billion tonne mark, a level not experienced for perhaps 50 million years. We are therefore entering uncharted territory, and no one can be quite sure what the outcome will be.
Some climate scientists have postulated that the melting of the north polar icecap and the Greenland ice sheet will release sufficient fresh water to “switch off” the thermohaline pump which drives the gulf stream. Global warming could therefore ironically result in another “Little Ice Age” with Northern Hemisphere temperatures falling dramatically while in the Southern Hemisphere, which is no longer cooled by ocean currents, temperatures and aridity rise. This is the scenario considered by the Pentagon in a 2003 paper on the national security implications of abrupt climate change. (An Abrupt Climate Change Scenario and Its Implications for United States National Security, Peter Schwartz and Doug Randall 2003.)
The effect on human societies would be devastating, as millions of square miles of cultivable land are lost both in the Northern Hemisphere — due to the onset of permafrost conditions — and in the Southern Hemisphere due to increased desertification. The authors of the report anticipate a fortress world, as hundreds of millions of refugees try to escape starvation.
But an even more devastating scenario must also be considered. 600 million years ago the Earth was entirely encased in ice and snow, with simple life forms surviving only in warm crevices beneath the frozen surface. Volcanic emissions of methane and carbon dioxide drove temperatures up — saving our planet from the fate that befell Mars. Consequently, within a hundred million years or so, the planet was considerably warmer than it is today. But as the planet aged, emissions from volcanoes slowed down and the climate stabilized. Otherwise we could have ended up with temperatures and atmospheric conditions as hostile and uninhabitable as those on Venus.
The positive feedbacks of the current warming, and especially the explosion of methane clathrates, may well pick up where the ancient volcanoes left off, forcing a chain reaction that could extinguish life on our planet altogether.
So, do dialectics matter or are they just pointless philosophy? I would argue that they are important for two reasons:
- The problems we face in the world are so momentous that in order to tackle them we need to be guided by the highest level of theory.
- The alternative to the dialectic — Aristotelian formal logic — is the mode of thought that holds sway in “common sense”, or more precisely in bourgeois common sense. If we want to tackle this ruling ideology, we need to tackle its philosophical roots.
Engels, in discussing the great flowering of scientific thought that followed the renaissance, noted that scientists at that time were hampered in their thinking by their acceptance of the Aristotelian world view. Thus Newton’s planets, once set in motion by God, would continue along their elliptical paths forever. Linnaeus’ species were as they had always been since the creation. Nature was essentially fixed and unchanging. Scientific advances in the 19th and 20th Centuries, such as the theories of evolution, the big bang, general relativity, electromagnetism and quantum mechanics, started to transcend this fixed view of nature.
However, Aristotelian ideas still dominate the general consciousness. Climate change has up to now been so gradual as to be barely noticeable, other than by specialists in the field. It takes a fair leap of the imagination to fully realize the implications of the qualitative changes that are lying in wait. And of course, we are encouraged to cling to this faith in the immutability of nature by the ruling ideology in general and by a fossil-fuel-industry-funded climate skepticism in particular.
The Aristotelian world view, this faith in the immutability of nature, is still a corner-stone of the ruling ideology. We find it difficult to comprehend our own mortality, never mind the mortality of civilization itself, or of our entire species. Yet that is what is at stake. The current rate of species extinction is around 1000 times the normal background rate. Our existence is far more precarious, and far more dependent on our ecosystem, than we would perhaps like to think.
But if we can dislodge this faith in the immutability of nature, and the evidence is there for all to see in the climate debate, that other great “constant” will also be called into question — the immutability of capitalism itself. Awakening our class to the materialist dialectic in the context of climate change will put revolutionary social change back on the agenda, particularly since the overthrow of capitalism will be the only practical means of countering the threat of environmental catastrophe.