300
the temperature of the earth is about 300 kelvin. surprisingly, the sun's warmth is the second biggest contributor to the beautiful weather of the south pacific. the biggest is the decay of radioactive materials deep within the earth. third is gravity. meteors fall to earth and burn up. that heats the air and hence the earth as a whole. the earth still has bunches of heat left over from its formation some 3.5 billion years ago. the last thing i'm going to mention is composition. it includes things like color, reflectivity, and specific heat. the last being the difference between tomatoes and meatballs.