How Is Marijuana Safer Than Cigarettes?

Research has shown that marijuana smokers show less evidence of lung injury as compared to people who smoke tobacco, because smoking cannabinoids protects them from developing a situation like emphysema.

A cigarette basically is a product created from cured and thinly cut tobacco leaves. These tobacco leaves are rolled and stuffed into a paper-wrapper cylinder. Over the period of years, the tax policies of various governments have led to the use of not just tobacco leaves but steams as well. The word cigarette, is commonly applied to tobacco cigarettes but can also be used for related devices comprising of other herbs, like cannabis.

A cigarette is different from a cigar mainly because of its smaller size, the application of processed leaves, and white paper covering, cigars are normally made from an entire leaf of tobacco.

Marijuana and cigarettes are two different things entirely except from the fact that you can smoke them both.
If you just smoke marijuana you'll only be taking the drags needed or smoking from a bong needed to get your desired high where cigarettes you'll be eventually taking in a lot more smoke depending on how much you do smoke. And I'm pretty sure the tobacco in cigarettes is more harmful to your lungs then the weed on its own.