Smoking cigarettes has long been proven to cause severe lung damage, including chronic obstructive pulmonary disease (COPD), emphysema, and lung cancer. Over time, cigarette smoke destroys lung tissue, fills airways with tar, COPD: Symptoms, Causes & Treatment Alpine BioMedical Research Shows Emphysema More Common in Marijuana Smokers Than Cigarette Smokers COPD What Smoking is Really Doing to Your Lungs ABILITY Magazine The Relationship Between Emphysema and COPD PAM Health