Wash the thermometer in soap and rinse with cool, clean water before and after you use it. Do not use hot water because the thermometer may break. After washing, it is best to soak the thermometer in alcohol for 20 minutes. You can use ethyl, isopropyl, or medical alcohol (ethanol).
1 In 2015, the average temperature across global land and ocean surfaces was 1.62Â°F (0.90Â°C) above the twentieth-century averageâthe hottest year in the 136-year record.  Since 1976, every year has been warrmer than the long-term average.
The global average surface temperature rose 0.6 to 0.9 degrees Celsius (1.1 to 1.6Â° F) between 1906 and 2005, and the rate of temperature increase has nearly doubled in the last 50 years.Temperatures are certain to go up further. Despite ups and downs from year to year, global average surface temperature is rising.By the beginning of the 21st century, Earthâs temperature was roughly 0.5 degrees Celsius above the long-term (1951â1980) average. (NASA figure adapted from Goddard Institute for Space Studies Surface Temperature Analysis. ).lobal warming is the unusually rapid increase in Earthâs average surface temperature over the past century primarily due to the greenhouse gases released as people burn fossil fuels.