Education. If you want to become an optometrist, you'll need about eight years of education. Depending on how fast you work, you might be able to graduate sooner if you take on additional credit hours or complete coursework during the summer.
Although the results for the Earthâs temperature are usually given as anomalies, climate scientists have used the measured temperature data to calculate average temperatures. NOAAâs result for the 20th century average land-ocean Earth surface temperature is 13.9 Â°C. The 2011 NOAA surface temperature anomaly of 0.51 Â°C, gives an average Earth temperature of 14.4 Â°C for 2011. To find out more about how the Earth is warmed and the greenhouse gases that are responsible, see How Atmospheric Warming Works and Greenhouse Gases.
The earth's average temperature rose by 0.8 Â°C (1.5 Â°F) during the last century. That change is in the mean global temperature that has been calculated for each year since 1880. The history of average global temperature is based on data gathered around the world at weather stations, on ships and by satellites.ike the earth as a whole, most of the Arctic's increase occurred during the last three decades. Near the North Pole, the mean annual temperature during 2000 to 2009 was 1.8 Â°C (3.24 Â°F) above the average temperature there for 1951 to 1980.