Meteorological networks with accurately calibrated thermometers and rain-gauges started to appear in the 19th century. Changing weather patterns leads to changes in many variables. For example, trees grow faster when it is warmer and wetter; different isotopes of oxygen are produced when it is warmer. Evidence of the changes can be trapped in trees, ice core, sediments, coral and stalagmites and used as “proxies” to estimate weather conditions hundreds and even millions of years ago.
In this section of the website we provide information on the following proxies for climate change: