Huge amounts of frozen methane gas is trapped in the permafrost,it’s being released as the temps rise and the permafrost melts. It’s not just Co2 that’s the problem,the term is greenhouse gases not gas.
They are considering calling polar bears marine mammals because they are spending more time in the water than on land or ice. Up in Churchill the bears are being land locked for up to 6 months,used to be a 3 month stay until the sea ice could support them. They are staving during this time as they can’t feed except for from human garbage. They are considered the most southerly population of polar bears, will be a real shame when they are gone.