Suppose the Orbit of the Earth Were 5% Smaller (a = 0.95 au) than it is today (a = 1.0 au). What would happen??

Not my field but;

More heat to the surface due to closer proximity to the sun.

Faster tides(by 5%)

Centrifugal forces different(gravity etc)

Just guesses on my part.

Hope it helps some,
Ken

It would be hotter, the Earth would orbit faster and so we would have a shorter year, There would be very little effect on the tides because they are governed by the moon.

With the rise in heat, most of the predictions for global warming would be a reality. Look them up.