The Goldielocks zone is not tiny by human standard. It's goes from about a third of earth orbit's radius, to 10x it's radius. However climate would be extremely different at 0.3x, 1x and 10x, which I assume is what you really meant.

The orbit of Earth is also extremely stable, barely changing, and with time the earth is getting farther from the Sun, not closer, as the Sun is slowing losing mass since it's burning fuel to produce heat and light. The speed at which we are getting further away is however ridiculously tiny: a few centimeters a year.

To give you a sense of perspective, earth is closest to the sun in January and furthest in July. It is ~5 million kilometers nearer in January, and that only amount to about 6 or 7% more solar energy received.

So, any deviation of earth orbit's over the past 100 years that would explain climate change would need to be massive. Not the kind of things we wouldn't notice, and also not the kind of things that would allow us to be talking about it today. If earth's orbit was changing that much, that would mean our solar system is not stable, probably making life impossible.

I used to think this until someone pointed out that the earth isn't a fixed distance from the Sun.. it varies throughout the orbit from a minimum of 91 million miles to a maximum of 94.5 million miles away.

So there's already a 3.5 million mile margin of error in our Goldilocks zone... we'd have to go way beyond a few miles of annual change to feel any impact.

All energy on Earth is derived from the Sun. The amount of radiation from the Sun, and the fact that it isn't constant nor uniform, is conveniently ignored in all the climate science I've seen.

It is also awfully very convenient to ignore the fact that Earth's climate has been ever changing since its beginning.