Explore how surface temperature changes when green house gases increase. This simulations was developed by the University of Colorado Boulder, part of the excellent PhET Interactive Simulations project with the aim to create interactive, research-based simulations that can aid in the understanding of complex concepts, link.

A big difference between low tide and high tide can be seen in Derby, Australia at this link. This is a natural change of sea level that happens every day due to the gravitational pull of the Moon and the Sun  on our Earth. 

This simulation was made by Vaclav Cernik for their University thesis to help students learn about our Earth and it's unique features, link.