Men and Climate

The Pharaoh Akhenaton together with the queen Nefertiti worshiping the Sun god, Aton, substituted for Amon as first-hand deity.

Ten thousand years ago, when our distant Neolithic ancestors were first starting to cultivate their fi elds, and scoured the woods and savannah in search of game with which to feed themselves, they used to look up at the skies, observe the clouds, keep an eye on the wind, and look out for rain and snow. Armed only with their four senses for measuring instruments, and with their intuition and logic for theory, they had to try to forecast the changes in the weather that governed their lives. We have practically no record of how these early humans related to the weather. Certain paintings in the Mas d’Azil cave in the Ariège region of France may depict the rain or the sun, according to the prehistorian Kassner. Today, it's with the help of high precision instruments, sondes, satellites and supercomputers that our contemporaries explore our planet's weather and climate. To get this far has required centuries of research, inventions and theories. It's an amazing adventure whose first tangible records go back as far as the 13th century BC in China, where inscriptions carved on bone have been found that relate weather phenomena (snow, frost, rain, wind, etc) recorded every ten days. However, there is no trace of measuring instruments.

To find the first recorded instrument, the ' nilometer ', we have to turn to ancient Egypt, where the priests had the crucial job of predicting the date and the size of the spring floods of the River Nile, which were vital for the region's survival. The experts of the time invented an ingenious system of wells with marks carved on their walls that were used to measure the river level. Thanks to groundwater infi ltration, and by comparing this with information gathered during previous floods, the Pharaoh's hydrologists were able to forecast the size of the floods as soon as the water began to rise. As was frequently the case in ancient times, mythology and meteorology went hand in hand. The all-powerful gods completely controlled natural phenomena: winds and tides, heatwaves and downpours, thunder and lightnings were exclusively caused by them. In India in 3 000 BC, for instance, philosophical texts such as the Upanishads connected the formation of clouds, the phenomenon of rain and the cycle of the seasons with the motion of the Earth.

Hippocrates, 460 BC - 370 BC

It was only with the advent of the Greek philosophers, first Parmenides and Herodotus (5th century BC), and then Hippocrates with his work 'Air, Water and Places', that the first global theories about climate concerning the whole planet emerged. We should remember that today we make a distinction between 'weather' and 'climate'. Weather has to do with the meteorological conditions in one place and over a short period of time. Climate, according to the World Meteorological Organization (WMO), is the synthesis of weather conditions in an entire geographical region over a long period of time. In short, the weather concentrates on the here and now, while the climate concerns entire regions over tens or even hundreds of years. As early as the end of the 4th century BC, Hippocrates divided the world up into different climate regions, contrasting Europe where the climate varied in a sawtooth pattern to Asia where there reigned a perpetual spring. In the 4th century BC, Aristotle wanted to find order within the world. The result was a coherent and rational approach, put down in the four volumes of 'Meteorology', an impressive treatise that described not only astronomical phenomena in the vicinity of the Earth such as comets, but also phenomena that affected the atmosphere, such as snow, hail, wind, etc. Aristotle also talked about the key role of the Sun which extracts 'fluxes of heat from the Earth'. Depending on whether they were dry or humid, they caused wind and rain, heatwaves or storms. Over the years, Aristotle's theories about climate became widely accepted. Admittedly, they were amended here and there by other philosophers such as Theophrastes, Posidonius and Aratos, but without them being fundamentally changed.

At the same time, the first measuring instruments were invented. For instance in around 40 BC, the astronomer Andronicos of Cyrrhos built in Athens the Horlogion, a wind tower 14 metres high that housed a hydraulic clock and a weather vane. Aristotle's work remained unknown in Western Europe for centuries, and right through the Middle Ages no scientific progress took place at all. At the time, the only instrument available to observe the weather was the rudimentary weather vane.

But the intellectual ferment of the Renaissance was to change all that. In the space of a century, the first instruments able to measure the main characteristics of the atmosphere were developed. Leonardo da Vinci took up the plans that the German mathematician Nicholas of Cusa had drawn up in the mid 15th century, and designed a new hygrometer where water was absorbed by a sponge. Galileo came on the scene at the end of the 16th century and designed the first air thermometer, whose graduations were developed years later by the Italian Santorre Santorio. At the same time, the German astronomer Johann Werner and the Danish astronomer Tycho Brahe carried out the first regular meteorological observations.