Tree rings and Pollen helps in measuring global temperature.
For a scientist studying climate change, “eureka” moments are unusually rare. by Dr. Nitish Priyadarshi photo credit:http:// boojum.as.arizona.edu I n 1938, British meteorologist Guy Stewart Callendar made the first proper measurement of global temperature. He gathered data from weather stations worldwide and found that the average temperature of the earth has increased between 1880 and 1930. Sadly, no one took his findings seriously. In 1957, two scientists set up instruments on the Mauna Kea Volcano in Hawaii to measure the level of carbon dioxide in the atmosphere. Its records show that the level of carbon dioxide has been increasing steadily since that time and that the earth is slowly warming up. For a scientist studying climate change, “eureka” moments are unusually rare. Instead progress is generally made by a painstaking piecing together of evidence from every new temperature measurement, satellite sounding or climate-model experiment. Data get checked and rechecked, ideas t...