Question

earths average temperatures have increased very slowly over time, possibly due to the increased concentrations of greenhouse gases in earths atmosphere. about how much has the temperature increased above 20th century averages? by around 1 degree c about 1000 degrees c

Explanation:

Step1: Consider climate - change facts

Earth's temperature increase due to greenhouse gases is a well - studied phenomenon. A 1000 degrees C increase is extremely unrealistic.

Answer:

by around 1 degree C