Why is the term global warming often used when referring to climate change? every location on earth is hotter every year than the year before.
the sea temperatures have increased by 20 degrees.
on average, the overall trend for the earth's surface temperature is increasing. none of the above are true.

The "greenhouse effect" is the term used to describe the retention of heat in the Earth's lower atmosphere (troposphere) due to concentrations of certain trace gases and water vapour in the atmosphere. These gases are generally known as greenhouse gases*. Concentrations of some of them have increased steadily during the 20th century and into the 21st, with CO2 rising from under 300 ppm to 400 ppm. A large part of the increase in all greenhouse gases is attributed to human sources, i.e. it is anthropogenic, hence the term ‘anthropogenic global warming’ (AGW).

the truman doctrine was an american foreign policy whose stated purpose was to counter soviet geopolitical expansion during the cold war. it was announced to congress by president harry s. truman on march 12, 1947, and further developed on july 12, 1948, when he pledged to contain threats to greece and turkey.