Which of the following is not a method for reducing global warming?
(1) limited use of fossil fuel so that less production of green house gases
(2) Increment in area of forest so that more CO2 used in photosynthesis.
(3) Promoting the use of air conditioner and refrigerators.
(4) Reduciag use of nitrogenous fertilizers in agriculture so that N2O is produced.
(5) Developing the option for chlornfluoro-carhons
