The term "Earth's surface temperature" can be misleading, as it often refers to air temperature measured several feet above the ground rather than the actual surface temperature. Land surface temperature is measured by satellites, which capture the temperature of various surfaces like snow, grass, or buildings, while air temperature is influenced by local conditions such as shade or wind. Ocean temperatures are derived from direct water measurements, making them distinct from air temperatures over land. The average temperature often cited in discussions about the greenhouse effect is derived from a combination of satellite and thermometer data, raising questions about the accuracy of historical comparisons. Understanding these distinctions is crucial for interpreting climate data and the implications of temperature changes.
