There's no land at the North Pole Instead it's all ice that's floating on top of the Arctic Ocean. ... Multi-year ice is thicker and has survived at least one melt season, whereas first-year ice is much thinner. Arctic sea ice usually reaches its minimum around mid-September each year.
One very specific way that humans caused changes in the atmospheric CO2 levels is the fossil fuels that the humans are burning is causing an increase in the CO2 levels. Other ways humans are doing this is by driving cars, deforestation, and an increased industrialization that releases CO2 into the atmosphere.
