It is now possible to see the effects of pollution and global warming by simply looking up. Depending on where you live, the pollution and suspended particles in the air make it less and less spectacular to stargaze.
Where I live, in a rural area, the stars can be amazing. Millions of flickering, bright stars. However as you drive towards even small cities, stars become less visible and in some areas, disappear entirely.
Take this graphic for example.
It is sad that some people will never experience what it is like to look up and be awed and humbled by the magnitude of the universe around us.
Neil deGrasse Tyson of the Hayden Planetarium points out that some children in New York, where he grew up, never knew there even were stars. Perhaps that is a reflection of our educational priorities as much as the state of our environment.
Pollution (both chemical and light) are the reason astronomers do their work in telescopes in rural areas with low humidity and wind which tend to suspend particles in the air and blow them around in front of lenses.
Take Australia as an example. An area with vast amounts of rural and undeveloped space as well as major metropolitan areas. “Public lighting is the single largest source of local government’s greenhouse gas emissions, typically accounting for 30 to 50% of their emissions. There are 1.94 million public lights–one for every 10 Australians–that annually cost A$210 million, use 1,035 GWh of electricity and are responsible for 1.15 million tonnes of CO2 emissions.”