Introduction and history of meteorology and climatology
Scientific measurements only became possible with the invention of appropriate instruments;
most had a long and complex evolution. A thermometer was invented by Galileo in the early 1600s, but accurate liquid-in-glass thermometers with calibrated scales were not available until the early 1700s (Fahrenheit), or 1740s (Celsius). In 1643 Torricelli invented the barometer, and demonstrated that the weight of the atmosphere at sea level would support a 10m column of water or a 760mm column of liquid mercury. Pascal used a barometer of Torricelli to show that pressure decreases with altitude, by taking one up the Puy de Dome in France. This paved the way for Boyle (1660) to demonstrate the compressibility of air by propounding his law that volume is inversely proportional to pressure. It was not until 1802 that Charles made the discovery that air volume is also directly proportional to its temperature. Combining Boyle’s and Charles’ laws yields the ideal gas law relating pressure, volume and temperature, one of the most important relationships in atmospheric science. By the end of the nineteenth century the four major constituents of the dry atmosphere
(nitrogen 78.08 percent, oxygen 20.98 percent, argon 0.93 percent and carbon dioxide 0.035 percent) had been identified. It had been long suspected that human activities could have the potential to alter climate. While the atmospheric ‘greenhouse effect’ was discovered in 1824 by Joseph Fourier, the first serious consideration of a link between climate change, the greenhouse effect and changes in atmospheric carbon dioxide also emerged in the late nineteenth century through the insights of Swedish scientist Svante Arthenius. His expectation that carbon dioxide levels and temperature would rise due to fossil fuel burning has sadly turned out to be correct.