80% of the atmosphere by weight is in the troposphere
6km high/deep at poles, 18km high/deep at equator
The highest flying bird gets to 11,000 m up, higher than an airliner
Above that are only very thin aeroplankton
The overwhelming mass of living things on land and air are within about 100m of the surface
How can the atmosphere be too big to change when it's only 1/2 the thickness of a sheet of paper?
Our planet's heat circulation system is thin and delicate
At 16 people per square kilometer burning fossil fuels at 17,500 kwh per person per year it's very much changeable
5 tons of CO2 per person, 80 tons per km^2 per year