1.1.1 From classical times to the Age of Discovery
As they sailed up the River Nile, the ancient Greeks noticed that it became warmer. Being logical in their search for explanation, they assumed that the earth must slope upwards towards the sun. The word âclimateâ traces its roots from this now discredited deduction, being derived from a Greek word meaning âslopeâ. But despite writings on climate by authors such as Aristotle and Hippocrates as early as the fourth century bc, progress in the study of the atmosphere was slow for almost the next two millennia. It was only with the Renaissance, when a renewed interest in exploration and overseas trade occurred, that the need to understand spatial variations in climate became obvious once again. In an Age of Discovery based on sailing ships, understanding the vagaries of the winds became vital. Later on, rainfall reliability, and thus water supply, became relevant matters for public health in urban areas. Amassing of large data collections began, aided by improvements in instrumentation. But, data collection alone does not help understanding, and organising and classifying of all kinds of weather data was the obvious next stage. Classification is never the most glamorous part of an emerging discipline and so climatology tended to become the âugly sisterâ of meteorology, its bookkeeping arm, until well into the twentieth century.
1.1.2 Determinism and possibilism
Making causative linkages between simplistic classifications of any phenomena can be dangerous, no less so with climate. It is tempting to infer that benign climates with few limitations in heat or moisture will be associated in general with productive agricultural or natural vegetation systems, and ultimately with the creation of an agricultural surplus which in the past provided the security for expansionism and economic development of all kinds. There may be considerable justification for this, especially in societies dependent on the annual harvest for their survival. It is entirely different, and misplaced, however, to extend this logic unquestioningly to issues related to cultural and economic development. Yet this was done widely in the early decades of the twentieth century. Such a philosophy, known as environmental determinism, implied control of human affairs by an external influence, namely the physical environment. Taken to its extreme, it consigned cultural and economic development to spatial and temporal variations in the physical environment. Progress, it was argued by determinists, was based on climate, heredity and culture. Mid-latitude climates, with their seasonal contrasts implying a constant need to plan ahead, were implicitly deemed superior as influences promoting well-being and intellectual development by comparison with their equatorial counterparts. In the aftermath of the Second World War this smacked of ethnic prejudice and was rightly considered totally unacceptable. Environmental determinism was discredited.
The pendulum swung towards possibilism â a denial of the importance of the physical environment. The featureless plains which characterised key economic and geographic models by Von Thunen, Weber and Chrystaller, pointedly played down the importance of the physical environment to the point of virtually ignoring its existence. Climatology, heavily tarred by the deterministic brush, languished. The proportion of articles dealing with weather and climate in key scientific journals fell from about 35 per cent in the second decade of the twentieth century to 4 per cent in the mid 1960s. However, just like determinism, advocates of possibilism also pushed their logic too far.
Awareness that all human endeavours must be accommodated within a physical setting, and within climatic constraints, dawned slowly. A paradigm that believed that technological advances could âfixâ the physical environment when required was dominant for long periods and remains deeply embedded in the psyche of some ideologies. Gradually, a more balanced perspective on the role of the physical environment has emerged. Concepts of stewardship, rather than domination, of the environment were learned the hard way. Some spectacular failures in agricultural expansion into marginal areas were instrumental in this. But gradually the relevance of a climatic perspective has become clear in a number of crucial areas. The âGreen Revolutionâ, the management of urban air quality, the emergence of the ozone hole, the growing toll of climate-related natural disasters, irrigation schemes, deforestation, soil erosion â all had important unanticipated climatic dimensions to them. But perhaps the clinching issue, which has led to climatology emerging as a vital discipline for humankind, has been the realisation that climate is itself changing over short and long timescales. Far from being prisoners of our climates as determinists suggested, climate is increasingly seen as a prisoner of human actions. The role of human action in contributing to most of the temperature change observed in the last 50 years (Figure 1.1) has now been widely accepted. At the annual meeting of the World Economic Forum, a global partnership of business, political, intellectual and other leaders held in Davos, Switzerland in January 2000, it was declared that climate change is the greatest global challenge facing humankind in the twenty-first century.
Figure 1.1
Global mean annual temperature trends from 1860 to 2002. The year 2002 was the second highest annual temperature recorded for the period with 1998 the highest.
Key ideas
- 1. A reactionary backlash to the philosophy of environmental determinism stifled the growth of modern climatology until recent decades.
- 2. Awareness of the central importance of atmospheric and climatic considerations in key areas of human endeavour has now grown enormously. This has particularly been demonstrated by the need to address pressing problems of climate change.
