On December 21st, the gravitational acceleration will suddenly change, and will no longer be 9.8 meters per second!

Of course that will cause changes in the atmospheric pressure, and the consequences may be catastrophic...

what do u say it will be?

so.... I should be training in my gravity chamber like goku was in all those episodes of dragon-ball z?

Yes!

How many meters per second will it be?

It's not clear yet...

Some people think it will be higher than 9.8 m/s² other people think it will be lower than 9.8 m/s²

If the change is too big, the consequent changes in the atmospheric pressure could be catastrophic...

Too low atmospheric pressure will make air too rarefied to breathe. We die suffocated.

Too high atmospheric pressure could kill us a well...

As in i'll be cooking and suddenly my head will turn to mush and not know whats what and dinner burns? As in, i wont know what to do so i will let the house burn down?
As in, we will all turn into drooling idiots?

Link or stink. Unless you have credentials your just another crazy person who thinks he's got shit figured out.

So we will be able to fly?

I can't wait.. No need for cars/trains/planes....
this will save our world from greenhouse gases.

If gravity increases a tad the boiling point of water will change

It would certainly coincide with something nostradamus predicted, that is "The day everyone will fall down".
Again something Brent Miller said couple years ago. I'm counting up the things he then claimed, which are now happening or somehow confirmed by science or events. They are stackin' up BIG time.

Well this didn’t age well

It's metres per second per second actually.

.................. and yes I believe that so the called fundamental constants of physics are a lot more malleable than conventional theories dictate, as per Electric Universe understanding.

earth is a fixed firmament, not a spinning ball