Okay, now super simplified!
The Sun's energy is trapped by the atmosphere like windows trap the heat in a closed car parked in the sunshine.
The atmosphere traps more energy than before because of the extra Carbon Dioxide and Methane released into it from our use of fossil fuels.
The extra trapped energy is experienced as hotter temperatures, longer droughts, heavier rains, stronger wind and ocean currents and stronger storms increasing in intensity year after year.
The effects can be slowed, eventually stopped and maybe reversed, but humans need to begin seriously cooperating now.
Replacing fossil energy with clean energy will make humans healthier, and wealthier.