Human activities, particularly fossil fuel burning, are increasing CO2 levels at a rate 300 times faster than natural processes observed during the last ice age, contributing to climate change and global warming. The current CO2 concentration of 400 ppm is similar to levels from 8 million years ago, with projections estimating it could reach 1000 ppm by 2100. The rapid melting of polar ice is intensifying winter weather extremes and is expected to raise sea levels significantly, with human influence acknowledged as the dominant cause of observed warming since the mid-20th century.