By replacing a Kerosene burner in India with a Solar Lantern you can prevent 400Kg of CO2 reaching the atmosphere each year.

It takes 4 trees 100 years to remove 400Kg of CO2.

Each Solar Lantern will prevent 4 Tonnes of CO2 reaching the atmosphere over it's 10 year life time.  To achieve a similar effect you would need to plant 40 trees and wait 100 years.