The International Space Station plus the number of orbital satellites and the growing number of space junk (space debris) and etc., have contributed to the losing of weigh of the Earth hence the change of distance.
See,
F = G * M1 * M2 / (R * R)
- R is the distance (radius) that separates two given objects.
- G is the gravitational constant that is 6.67259x10-11m3/s2 kg.
- M1, M2 the two masses that are attracting each other.
- F is the force of attraction between them.
Now, when Earth is in the closest point to the Sun, we have warmer temp's than previously*.
How to explain colder temperatures?
I'll answer that later.
Believe me, its easy.
Thanks for reading.
(*) I also have other reasons for warmer summers, none of which would involve human pollution as the main factor for it. Sorry if I disappointing you.