Solar activity changes throughout the year. Ironically the Earth is closer to the sun in winters than summers. This is explained by the direction of the Sun's rays. In the summer time the rays from the Sun are more direct than in the winter. The Earth's average distance from the Sun has not significantly changed in eons or now. A variant temperature of 1.6 degrees has been reported in the last 150. Meaning the Earth's average temperature has increased during this time. The inexact methodology of temperature measurement prior to satellites makes me highly skeptically that pre 1970 world-wide temperatures are accurate. People have perceived the world is becoming warmer, yet the evidence is not there. When analyzing planetary temperatures many factors come into play, Global atmospheric pollution potentially can trap heat in our atmosphere and on terra firma. We are nowhere near the concentrated atmosphere Venus has with an average surface temperature approaching 870 degrees. With all that stated your perception of increasing air temperatures is shared by many, yet science has not found a basis for it. Thank you for allowing me to answer your question.