What he says about the Earth's rotation slowing down due to rising sea levels is patently ridiculous.
Sea levels don't just rise out of nothing, they rise because ice melts. If ice that is floating in the oceans melts, nothing happens to the water level, but if ice that is sitting on land above sea level melts and runs down to the oceans, the water level rises. This does not slow the Earth's rotation by "increasing the radius of the Earth." If you move a large mass of frozen water from, say, the ice covering Greenland, and distribute it into the oceans, you're not increasing the radius of the Earth -- if anything, you're redistributing mass from a higher radius (on top of land) to a lower radius (in the ocean), which would decrease the Earth's rotational inertia, and actually speed up its rotation, but the effect would be so small it would be difficult to measure.
