Climate Change(d)?

[Jimmy Higgins]

As I said I forgot thermal expansion of sea water.

A significant factor. A 1 °C increase in the mean temperature of the entire ocean*, would raise global mean sea level by over thre quarters of a meter! Of course there are thermally stratified areas of ocean that would mix at different speeds, and Santa Monica will probably be ok well past the lifetime of its only resident that matters.

* afaik that would mean several degrees of warming in the "hot spots", while the depths are barely effected. But the influence on weather is mainly driven by surface temps, so... bad news will likely precede any such sea-level rise.

When you say the "entire ocean" are you talking shallow surface area or total volume? That sounds like a total volume claim, as water is generally incompressible and "shallow" bodies of the surface water shouldn't possibly be able to expand that much. And I don't think we are going to see the entire volume of ocean warm that much.

 

[Elixir]

As I said I forgot thermal expansion of sea water.

A significant factor. A 1 °C increase in the mean temperature of the entire ocean*, would raise global mean sea level by over thre quarters of a meter! Of course there are thermally stratified areas of ocean that would mix at different speeds, and Santa Monica will probably be ok well past the lifetime of its only resident that matters.

* afaik that would mean several degrees of warming in the "hot spots", while the depths are barely effected. But the influence on weather is mainly driven by surface temps, so... bad news will likely precede any such sea-level rise.

When you say the "entire ocean" are you talking shallow surface area or total volume? That sounds like a total volume claim, as water is generally incompressible and "shallow" bodies of the surface water shouldn't possibly be able to expand that much. And I don't think we are going to see the entire volume of ocean warm that much.

Right. The surface would warm a LOT by the time the challenger deep went up a full degree. I don't know what percent of all the water in the oceans are involved in the "conveyor" currents, but that is the part that matters most to climate. OTOH, evidence suggests that sea levels have varied by hundreds of feet just in the last few milennia. I think most of that variance is due to ice formation and melt, not thermal expansion and contraction, but it's still a biggie as far as currently low lying areas are concerned.