“Climate change” and “global warming” are often used interchangeably but have distinct meanings. Similarly, the terms “weather” and “climate” are sometimes confused, though they refer to events with broadly different spatial- and timescales.
Global warming is the long-term heating of Earth’s climate system observed since the pre-industrial period (between 1850 and 1900) due to human activities, primarily fossil fuel burning, which increases heat-trapping greenhouse gas levels in Earth’s atmosphere. The term is frequently used interchangeably with the term climate change, though the latter refers to both human- and naturally produced warming and the effects it has on our planet. It is most commonly measured as the average increase in Earth’s global surface temperature.NASA
Global warming refers to the actual increase in the average atmospheric and oceanic temperatures in the recent decades.
During the 20th century, the earth’s surface temperature increased approximately 0.6°C +/- 0.2°C
See the most recent studies regarding Earth’s approximate surface temperature increase at NOAA
Since 1979, land temperatures have increased 0.25°C per decade compared to 0.10°C for aquatic ecosystems.
Research from NASA revealed that 2005 has been the warmest year on record since the late 1800’s which exceeded the previous record set in 1998 by several hundredths of a degree Celsius