Does the Earth currently weigh more than it did when it was first formed?
This is one of those questions that really doesn’t have a correct answer. The Earth really doesn’t have a weight at all. Weight is the measurement of the gravitational pull of one object on another. Most objects are too small to consider, like you and me, or the keyboard I’m typing on, but the Earth is big enough to notice the gravitational pull.
I’ll start by explaining a couple basics. Everything, all matter, has some gravitational pull. You and your shirt are currently pulling towards each other, but there is so little mass in both you and your shirt that you don’t notice it. You have a weight relative to the gravitational pull of the Earth itself, a smaller object like the moon will have less gravitational pull because it has less mass, that’s why things weight less on the moon.
For the Earth to have a weight at all it would have to be relative to some object, like a larger planet, but since the Earth is not on another planet we can’t really measure it in terms of weight.
Now that the concept of weight is settled, I’ll revisit the question in terms of mass, since weight is directly related to the amount of mass. The Earth is a closed system, which means that if a tree is cut down or a dinosaur killed the Earth will not lose or gain any mass. The dinosaur may lose mass but that mass does not leave the Earth, it simply goes somewhere else. That being said it is possible for the Earth to lose and gain mass, but the amount of mass it would gain or lose is quite insignificant, it would be like plucking a hair off your head and saying that you just lost some mass, or weight, not a good dieting system.
I can think of one way for the Earth to lose weight, when humans launch space craft or satellites the Earth is losing some mass, not much but a little. I can also think of only one way the Earth can gain mass and that is through asteroid collisions. Since we have only been launching objects off the planet for 60 years or so and we’ve been being hit by meteorite for over 4 billion years, I would think that the Earth has gained some mass since it first began, but again the difference in the Earth’s mass between then and now is so insignificant it’s not worth mentioning.
Technically I suppose the Earth has gained some mass, but really it’s pretty much the same as it’s always been.