evidence: Polar bears depend on the sea ice as a platform for hunting seals, the mainstay of their diet. They also rely on the sea ice for breeding, roaming, and sometimes denning. But the most significant thing to understand is that sea ice is far more than a platform: It's an integral part of the Arctic ecosystem. Sea ice is the "soil" for the Arctic marine food web. As the salty ocean water freezes, the salt is pushed out, creating briny channels and pockets underneath the ice. Tiny microorganisms thrive and grow in this unique environment. These small organisms play a key role in the Arctic food chain, creating a food base for Arctic cod, which then feed ice seals, which then feed polar bears. [...] Rather than being distracted by thoughts of fake ice or floating platforms, societies around the world need to act with urgency to halt global warming. If we don’t, sea ice ultimately will disappear and so will polar bears. We view the situation of diminishing sea ice in the Arctic as extremely serious but not hopeless. The key to saving sea ice and getting our climate back to functioning the way it should is to move away from using fossil fuels like oil, gas, and coal altogether, shifting instead to energy sources like wind, solar, and water. As this shift is underway, we can also help by embracing energy efficiencies that reduce our use of fossil fuels and by choosing green energy options if they’re available in our communities.