This only applies to the metric system. For the empirical system, it gets even more confusing. Here's a simple quote from NASA's Pre-Jesus era website:

The effective acceleration of gravity at the poles is 980.665 cm/sec/sec while at the equator it is 3.39 cm/sec/sec less due to the centrifugal force. If you weighed 100 pounds at the north pole on a spring scale, at the equator you would weigh 99.65 pounds, or 5.5 ounces less.

Whenever we talk about weight in pounds, we need to define where with respect to the center of our little bluey.

Not exactly... grams measure mass, not weight. Imperial Units have the 'slug', which doesn't change based on where you are measuring.

The metric system DOES have units of measurement that change based on where you are at on the globe, called newtons.

I get what you're saying, but just to be clear, the value of a Newton doesn't change. It would be pretty useless as an SI unit if it did.

"One newton is the force needed to accelerate one kilogram of mass at the rate of one metre per second squared in direction of the applied force."

1 newton is 1 newton if you're on earth, in space or at the centre of a sun.

1kg on earth will exert approx 9.8N (1 kg * 9.8m/s^2) towards the centre of the earth, where as 1kg in orbit will exert almost 0N towards the centre of the earth.

I hear the official kilo in Columbia is a little different, but considerably more popular.