"Why does water boil easier in a lower pressure?"
Far as I'm aware, water doesn't boil easier in lower pressure- it boils at lower temperature, but not more easily.

"Why does evaporating water cause a cooling effect?"
Well anything that evaporates causes cooling- but has water has high latent energy- and that is probably due how water is structurely formed at molecular level.

"Why do the planets Mars and Jupiter have higher wind speeds in their atmospheres than the Earth?"
Well, Earth's jet stream moves pretty fast. And I'm not sure, that we have measured Earth's winds that much at say +100,000'. Earth's atmosphere relative to Mars is very thick and therefore has relatively high viscosity. Jupiter is mostly Hydrogen and Helium- and we know very little about it's lower atmosphere.

"Why does the high altitude "jet stream" move faster than the low altitude air?"
Lower density less resistance- and it acts like any stream- finds a pathway and this is self-reinforcing. The colder air falls generally towards warmer lighter air.

"Why does radioactive material heat its surroundings?"
Because it's emitting radiation.

"Is there more radioactive material in the atmosphere now than there was before our "nuclear age"?"

Coal plants emit a lot of radioactive material- not sure whether nuclear bombs have put more radioactive material in atmosphere than compared to coal plants. Not sure if all radioactive that human activity has added to atmosphere is significant. I would agree that an alien civilization could detect the type of radioactive material in Earth and surmise that an advanced civilization was on Earth. But on the simple level of just more radioactive material vs less radioactive material- that would be less clear.

"If the kinetic energy of air molecules becomes extremely high, can such molecules escape the Earth's gravitational field?"
Of course.

"Ones these questions are answered and the physics involved in the phenomenon understood, then the global temperature changes can also be understood in greater depth."
Hmm, perhaps.
I got a few questions.
If you were to design a greenhouse on Earth- say a 100 meter diameter dome- and you designed it to get as hot as possible, how hot could you make the air in it?
And if you put this greenhouse on the Moon with 14 days of sunlight could you get significantly hotter temperatures than compare to same greenhouse on Earth. Can you give some ways in which this could be designed- and could descibe the cheapest way of doing this.
Now, with given a type of standardized "greenhouse" what would the temperature difference be if instead of Earth orbital distance, it was 5 million miles closer to the Sun? 10 million miles closer to the Sun? And say 10 million miles further from the Sun?

Btw. Luna surface's mean day temperature is 107°C. The lunar surface is mostly dark material and it's in a near perfect vacuum. I'm unaware of any detailed thermal map of the Moon. What would the mean temerature of the moon be if one was only measuring a section of the Moon near it's equator and only when the this section had sun at noon in the sky. It seems as though it would be higher than 107 C. And if you had a map at say 1 meter resolution of equator at noon what would this tell you about the Moon?