Change and climate inseparable

Climate' and 'change' go together like 'weather' and 'change'. The two are inseparable. Of course, the weather changes from hour to hour, day to day and month to month. Climate is just big weather. Karen Bice, of Pennsylvania university's department of geosciences, gives the following definition: "Climate," she says, "equals weather 'averaged' over a time period of more than one year or more". So there is nothing unusual about climate change per se. In fact climate without change is impossible. Climate change has never ceased, is ongoing and must therefore be considered inevitable. Or - to use an ideologically loaded phrase - it is natural. Notions of fixing in place the climate as it now is, or returning it to a pre-industrial ideal, through some kind of technical wizardry or human exodus, are half childish, half sinister and totally bound to fail.

Think about Britain's climate - a solid record of it lies in the rocks under our feet. As well as periodic glaciations over the last 20 or 30 million years - in the Quaternary and Tertiary periods - temperatures have in general been far higher in the past than today. For example, the coal seams of Yorkshire, south Wales, Lanarkshire and Nottinghamshire were formed in tropical forests and swamps; Dover's white cliffs were laid down under shallow, balmy seas; London's clay contains the remains of elephants, hippopotamuses and rhinoceroses. The claim that the hottest 10 years "since records began" occurred in the last decade might apply in terms of reports issued by the London meteorological centre, but hardly when one considers the geological time scale.

The drift and configuration of the continents might possibly explain our present climate, at least in part. A huge ring of American and Eurasian land more or less encircles the northern pole; that and the continental plate centred on the southern pole provide almost perfect conditions for ensuring cold conditions and freezing the bulk of the Earth's fresh water in two gigantic ice sheets.

Pangea, which existed some 225 million years ago, joined together most of today's land masses in one supercontinent, which primarily occupied tropical latitudes. This configuration helped produce much warmer climatic conditions. The US Science Foundation gives a figure of 10°C higher. Leave that theory aside; during the Mesozoic and Palaeozoic eras - which together cover many millions of years - the Earth was a considerably hotter place than now. An undisputed fact. Even in more recent times - ie, over the last few million years - the climate has been generally warmer than today.

However, climatic statis is always relative and temporary and is constantly punctuated by rapid change - mostly involving transition periods lasting perhaps a century, sometimes a few decades or even less than that. Till recently most scientists thought that all large-scale global and regional climate changes took place over a time scale of many centuries or millennia: ie, at rates hardly noticeable during a human lifetime. Gradualism was the ruling orthodoxy. That is no longer the case.

Scientific opinion nowadays recognises that quantitative change reaches a trigger point and then flips into qualitative change. Climatologists Jonathan Adams, Mark Maskim and Ellen Thomas vouch that "All the evidence indicates that most long-term climate change occurs in sudden jumps rather than incremental changes". Such conclusions were long anticipated by Marxism. Frederick Engels in his Dialectics of nature described the jump, or leap: ""¦ in so far as qualitative change takes place ... it is determined by a corresponding quantitative change".

Over the last million years there have been large-scale oscillations in the global climate, producing an interglacial-glacial-interglacial 100,000-year pattern. Each cycle has had its own particular features and oddities. Understandably, though, as with any study of the past, data becomes ever more unreliable with increasing distance. So the best records we possess go from the interglacial, known as the Eemian, down to the present Holocene period - the last 130,000 years have in particular been revealed in some detail with deep ice cores drilled from Greenland and the Antarctic.

In terms of climatic transition the most detailed information is for what is called the Younger Dryas-to-Holocene, which ended the last ice age. At its maximum, some 15,000 to 20,000 years ago, the Arctic ice sheet extended all the way down to near the Thames and saw much lower sea levels. Huge volumes of water were trapped in snow and ice. What is now Britain was joined to France. The transition to a new climatic regime occurred about 11,500 years ago and seems to have taken only a decade or two to complete: "The speed of this change is probably representative of similar but less well-studied climate transitions during the last few hundred thousand years," argue Adams, Maskim and Thomas. These transitions include sudden cold events (Heinrich events/stadials), warm events (interstadials) and the beginning and ending of long, warm phases, such as the Eemian interglacial.

Many causes, including ocean currents, sun spots, volcanic eruptions, cloud cover, CO2 and methane concentrations, planetary wobbles, ice caps and meteorite and comet strikes have been invoked to explain these sudden transitions. Doubtless a combination of these and other factors were at play.

There are less dramatic but nonetheless significant patterns of climate change on a smaller scale too. During the present (Holocene) interglacial period, there have been cold and dry phases occurring over a roughly 1,500-year cycle, and climate transitions on a decade-to-century timescale. There have been 'little ice ages', as well as bursts of relative warmth. Between 1100 and 1300, for example, Europe enjoyed temperatures which were on average 0.7° to 1.6°C higher than today. That encouraged more productive agriculture throughout the continent and saw flourishing English vineyards.

It is also worth recalling that the Thames regularly froze solid during mid-17th century winters and that the years from 1805 to 1820 were comparably bleak and inclement. So what we are experiencing at present needs to be put into the context of the transition from the little ice age which finally ended around 1880. Not that there is a straightforward linear trend. From 1946 till the 1970s things turned somewhat cooler and only since then has there been a return to warmer conditions - though admittedly still cool compared to the distant past and geological time.

Climatic change can produce both new opportunities and terrible calamities for us humans. Palaeontologists suggest that climate change played a major part in the emergence of our species. Growing polar ice sheets and the spread of the African savannah coincided with the split between our ancestors and modern chimpanzees. Subsequently, other glacial periods and low sea levels facilitated the human colonisation of Australia and then the Americas. Getting to Australia from Asia 70,000 years ago needed only a short hop from the island of Timor; and 22,000 years ago Siberia was connected to Alaska by the Baring land bridge. Tribal groups, perhaps only five in all, simply wandered in and then over the next 10,000 years or so peopled the whole of the Americas down to Tierra del Fuego.

Archaeologists blame sudden climate change for the collapse of the classic period of Mayan civilisation, and alternating wet and dry periods seem to have played a role in the rise and fall of the coastal and highland cultures of Ecuador and Peru. The beginning of crop agriculture in the Middle East certainly corresponds very closely with a sudden warming event which marks the beginning of the Holocene. Milder weather saw Norse colonists establish permanent settlements in Greenland in the 10th century - the population finally petered out in the 15th century, due in part to the "cooling conditions in the north Atlantic", brought about by the little ice age that began in the 13th century.

Of course, the climate is chaotic and subject to countless interacting variables. Modelling accurate predictions, especially long-term ones, are therefore fraught with immense difficulties. After all, we do not understand exactly why or how changes occurred in the recent geological past. Hence we largely remain in the dark when it comes to forecasting future events. Even if we knew everything there was to know about past climate mechanisms, "it is likely that we would still not be able to forecast such events confidently into the future". This is because the climate system and its chaotic nature means that comparatively tiny quantitative changes can suddenly result in qualitative changes in the initial conditions. The so-called 'butterfly effect'.

So no-one can reliably talk in terms of what will 'definitely' happen even in the near future. After all according to one model global warming might lead to Europe freezing. All that can reasonably be said is that there are possibilities and probabilities. There is the possibility that the climatic instability seen in the recent geological past is not relevant to our immediate future, because it represents a different system; a 'glacial' state, almost certainly characterised by an entirely different pattern of deep-sea circulation. However, there is the probability that there is a correlation with large-scale global shifts that occurred within earlier interglacials (eg, the Eemian and the Holstein Interglacial in Europe).

As shown by past glacial (eg, the ending of the Younger Dryas) and interglacial (eg, the various Holocene climate oscillations leading up to the 20th century) conditions, climate has a tendency to remain relatively stable and then suddenly leap, sometimes over just a few decades, due to various triggering or feedback mechanisms. Doubling the amount of CO2 in the atmosphere could be enough. A relative pin-prick, but climate is a temperamental, easily roused and vengeful monster.

Most climate scientists and the whole gamut of environmental protest groups believe that today's changes in temperature and sea levels are at least in part down to human beings. We must certainly factor into any calculation the extra complexities caused by the pin-pricks of human activity: eg, greenhouse gases resulting from air and road transport, domestic heating, power stations, industry and agriculture. Paul Crutzen, the Dutch Nobel prize winner, has even talked of the Anthropocene beginning 200 years ago with the industrial revolution. So the warning that human activity is in danger of bringing about another sudden climatic transition have to be taken seriously. Judging from what we know of the past, the quantitative conditions seem to be building up for a qualitative leap and another dramatic change in the climate system. Worst-case scenarios have temperatures in 2100 soaring by 6°C, with all manner of runaway consequences.

Soberly recognising that we might be living on a knife's edge when it comes to climate is not to indulge in historical pessimism or hysterical doom-mongering. Does that mean we should simply trail behind the green agenda in the copycat manner of Respect and the Socialist Workers Party? No, we must develop our own Marxist environmental programme and counterpose it to green environmentalism, which is always partial, typically naive and, as we have already explained over taxation, often anti-working class.

Communists readily admit that climate change cannot be halted. Sudden climate change is perhaps another matter. With our current knowledge, resources and capabilities, whatever humanity does, there is the likelihood that sooner or later a new ice age will take hold and once again considerably reduce sea levels. Equally there is the likelihood that there will be warmer and even hot periods - periods which will see some low-lying coastal areas and whole islands disappearing under the rising waves.

There are those who foolishly imagine that humanity already possesses all the necessary technology needed to reverse or simply call a halt to climate change. Eg, Respect's Jonathan Neale at last month's Respect conference (needless to say, he is a leading member of the SWP). Then there is the Campaign Against Climate Change. The name says it all. Quite frankly, no matter how well intentioned, such a clumsy name amounts to a plea for the entire world to collectively emulate king Canute of the 11th century.

Technoquack solutions to stop climate change would in all likelihood release a Pandora's box of demons. What is on offer was proudly put on display a couple of years ago when British and American 'experts' got together at Cambridge University. They were encouraged to think up a range of technological solutions to global warming. Amongst the other forms of madness they suggested were firing dust into the upper atmosphere; stationing a giant, 2,000-kilometre-diameter eye patch in space to deflect 2% of the sun's rays; growing huge algae beds in the oceans to absorb carbon dioxide; building massive cloud-generating machines, etc.

Attempts at planetary engineering now - especially with the alienated drives of capital and vast lacunas in our knowledge - are bound to produce completely unintended, potentially cataclysmic, consequences. After all, even the best weather forecasts cannot accurately tell you what things will be like in just a month's time. But surely some time in the future humanity will develop the theory and the necessary means for reliable manipulation. Climate change could be nudged or eased in this or that direction. Our descendants will then usher in the real Anthropocene that will see the greening of deserts and the general enhancement of nature for the benefit of humanity.

Undoubtedly there will be many problems if temperatures soar in the short term. But the answer to such a monumental challenge lies neither in a reliance on so-called 'pure' science nor the futile attempt to green capitalism.