A British think-tank has published a report for next year's United Nations Strategic Drug Policy Review that highlights the fact that marijuana is far safer than alcohol. According the Beckley Foundation's Global Cannabis Commission:

"[I]n terms of relative harms [marijuana] is considerably less harmful than alcohol or tobacco..."

"Historically there have only been two deaths worldwide attributed to cannabis, whereas alcohol and tobacco together are responsible for an estimated 150,000 deaths per annum in the UK alone."

 The full report, which calls for the decriminalization of marijuana to reduce the harm associated with the drug (which it suggests are primarily the result of laws against it) is available here.