What is Earth's average temperature as a whole?
What is Earth's average temperature as a whole?


Sealing the planet or using $E = mc^2$ isn't a practical means to measure the temperature. Here's how the average is usually determined:

Source: Tufts University - Global Warming - Heating by the greenhouse effect


  "... the average surface temperature of the planet is 288 degrees kelvin (15 degrees Celsius or 59 degrees Fahrenheit).".


Source: Space.com - What Is Earth's Average Temperature?


  "According to GISS, the global mean surface air temperature for that period was estimated to be 57 F (14 C). That would put the planet's average surface temperature in 2017 at 58.62 F (14.9 C).".