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Is there hard data showing sea ice melt causes ocean levels to rise? Because water will displace the same mass whether it is frozen or not. The best explanati

by yters 9y ago

Is there hard data showing sea ice melt causes ocean levels to rise? Because water will displace the same mass whether it is frozen or not. The best explanation I've heard is the loss of reflection from the sea ice will cause the water to warm, and warm water is less dense. But most sea ice is underwater, so am not sure just how much reflection is lost, and how much that affects the sea water warming.

mikeash 9y ago
The main concern for sea level rise is the melting of land ice in e.g. Greenland and Antarctica.
- yters 9y ago
  Last I researched, the land ice was melting a lot, but then refreezing a lot. It seems that sea ice is the main thing disappearing.
gerdesj 9y ago
"Because water will displace the same mass whether it is frozen or not." Why do bergs float and have a bit sticking up out of the water? Why do ice cubes in my G&T insist on floating? Sea ice melt is a bit of a worry if you are a polar bear that hunts on pack ice but for sea rise the real snag is land based glaciers melting into the sea. Greenland may be off your radar but it is a bit of a worry - lot of ice turning into water there, along with other places.
- msandford 9y ago
  But why do they float? Because they're less dense than the liquid water that surrounds them! If they were exactly the same density they wouldn't float. But since they're less dense, they stick out an amount proportional to their lowered density.
- greglindahl 9y ago
  Sea ice melt is a huge worry because it changes the albedo of the polar ocean. That means more heating from the sun, which means a warmer Arctic and a warmer planet. It's one of the positive reinforcement mechanisms that's a huge worry to the climate community. Greenland melting is also huge, and sea ice melting will make it go faster.
  - yters 9y ago
    But how much does it actually change the albedo? Are there hard numbers and analysis? Most of the sea ice is below the surface, so a lot of sea ice melt does not necessarily translate to a large change in albedo.

by yters 9y ago

mikeash 9y ago

The main concern for sea level rise is the melting of land ice in e.g. Greenland and Antarctica.

yters 9y ago
Last I researched, the land ice was melting a lot, but then refreezing a lot. It seems that sea ice is the main thing disappearing.

gerdesj 9y ago

"Because water will displace the same mass whether it is frozen or not." Why do bergs float and have a bit sticking up out of the water? Why do ice cubes in my G&T insist on floating? Sea ice melt is a bit of a worry if you are a polar bear that hunts on pack ice but for sea rise the real snag is land based glaciers melting into the sea. Greenland may be off your radar but it is a bit of a worry - lot of ice turning into water there, along with other places.

msandford 9y ago
But why do they float? Because they're less dense than the liquid water that surrounds them! If they were exactly the same density they wouldn't float. But since they're less dense, they stick out an amount proportional to their lowered density.
greglindahl 9y ago
Sea ice melt is a huge worry because it changes the albedo of the polar ocean. That means more heating from the sun, which means a warmer Arctic and a warmer planet. It's one of the positive reinforcement mechanisms that's a huge worry to the climate community. Greenland melting is also huge, and sea ice melting will make it go faster.
- yters 9y ago
  But how much does it actually change the albedo? Are there hard numbers and analysis? Most of the sea ice is below the surface, so a lot of sea ice melt does not necessarily translate to a large change in albedo.