A new report claims the UK government should legalise marijuana because it's “the only solution to crime and addiction problems”.

The strongly-worded study - titled The Tide Effect: How the World is Changing its Mind on Cannabis - was produced by the nonpartisan Adam Smith Institute and has the backing of several cross-party MPs including former deputy prime minister, Nick Clegg.

Cigarette and alcohol use among 15- and 16-year-olds is declining across Europe but the numbers using cannabis are growing, an EU survey shows.

The Espad report for 2015 includes most EU countries, but not Germany or the UK, and data for Spain is incomplete. 

In 2015 "current smokers" accounted for 21% of those surveyed, and the highest total was in Italy (37%). 

In 1995-2015 those using alcohol in the past 30 days fell from 56% to 47%. Top in cannabis use were the Czechs (37%).

That figure for Czech teenagers reporting a lifetime experience of cannabis was higher than the level in the US - 31% in comparable surveys. 

Marijuana legalization has been a political issue in the United States for some time, and while it remains illegal in most states, others have softened their stance in recent years. Colorado and Washington both passed initiatives by popular vote to decriminalize and legalize cannabis in 2012. In 2014, Oregon, Alaska and Washington, D.C., followed suit. Many states including Massachusetts, California, Missouri, Hawaii, Maine, Nevada and Ohio have flirted with legalization for a few election cycles, with buzz growing.

The United States isn't the only country where people use marijuana legally or illicitly. In fact, it isn’t even the country with the highest reported marijuana use.

If you are in the international market for marijuana, your legal options are limited. Though the cultivation of pot is widespread across the world, its legal status has only just begun to shift, with some countries choosing to decriminalize the substance and others loosening up enforcement regulations for users and growers.

The plant can grow just about anywhere, making it generally accessible to the global population, and, subsequently, one of the most commonly used illicit substances everywhere from the Americas to Europe. According to the United Nations Office on Drugs and Crime, there are more than 177 million cannabis users globally.