How come, if melting ocean ice is a threat, melting lake ice is not?

lake ice is fresh water melt into fresh water lake - nothing happens

ocean ice is fresh water melt into salt water ocean - could have some consequences

the main concern is ice sitting over land that melts into lakes and oceans causing them to rise.

Why the hyperbole statements? No one is claiming melting ocean ice will "kill us all".

In the first place, neither ocean ice or lake ice are going to have any direct affect on raising the sea-level. It's land-based ice that as it melts (or calves) into the ocean that will have an effect. But the thermo expansion, because warmer water takes up more volume, will probably have the largest effect in the near-term.

Best estimates are currently in the range of 0.5 - 2 M rise by 2100. While that doesn't seem like much (it certainly won't kill us all) to a person living at 5000' elevation in Denver, it's a big issue for many cities right near sea-level.

Any how What U asked is right all the Melting ice either the lake ICE or the river ice is going to merge with so ultimately sea level is going to rice so we are caring about and the Sea and the population is very high near sea and the population is low in the lake ice and river ice place and even the population will be zero here.

The problem is not lake ice. The oceans enormous ice shelves hold about 30% of the worlds water. This is the artic ice, so if those melt then water levels would rise. San Diego, new york, Charleston would flood. Lake ice is a threat but not nearly as bad as the amount of water stored in the huge antartic ice shelves.

I'm not sure where you are getting your information, but the ice melt we're concerned with is that which is on land that melts into the sea. Ice already in the sea or river is inconsequential, because it's like the ice cube in your drink. It's already displaced a certain volume. If the ice on Greenland or Antarctica were to melt, that is like adding more water to your glass, and what we worry about.

Melting Ice in rivers can cause flooding down stream and depending on the level of the lake before it froze over, the amount of snow accumulating on top of it and the amount of rain that we get in the spring you can get an expansion onto the beaches, but I've never heard of a lake actually expanding so much that it cause a flood, but I guess it could if there's enough accumulated snow and ice plus a good amount of rain fall.

Hunting and poaching is also a threat to polar bears. By the 1970's hunting and poaching had almost wiped out the polar bears. The populations fell to as low as 10,000 in the entire world. Because of global cooperation (not an easy feat in the midst of the cold war) restrictions on hunting were placed, and polar bear populations have started to make a come back. So, while some polar bear populations are increasing because of restrictions on hunting,[1] almost everyone agrees that, now, the overwhelming threat to polar bear populations is the loss of sea ice.[2][3] The Arctic is expected to be ice free during summer months by mid century. By some accounts this will happen as early as 2013. Polar bears are considered marine animals because of their integral link to the sea and to sea ice. They live much of their lives on the sea ice; it serves as a moving platform from which they hunt seals – the mainstay of their diet.[4][5] Because of loss of arctic sea ice, the US Government, Department of the Interior, predicts that Alaska's entire population of polar bears, along with 2/3 of the world's polar bears will be gone by the middle of the century.[6] Currently, of the 19 polar bear populations, the two which where most affected by over hunting are still recovering. The two most studied populations are known to be declining. And there really isn’t enough information on the 15 other population to determine if the numbers are faring with climate change.

There has been plenty of talk about melting lakes and rivers, especially in Alaska, which are very dangerous. The melting of this ice is releasing deadly amounts of methane from the rotting vegetation below. I saw it on tv, they aren't trying to hide it from anyone. Maybe you just haven't been watching!

If you're referring to the melting Ice caps, it's all about scale.

The ice caps are huge, if they melt it will seriously affect water levels and flooding a lot of the low lying lands. (East anglia in Britain, The Maldives etc...)

You are mistaken. Ice already water borne will not significantly effect sea levels. Ice on land, that melts WILL!