As the federal Liberals map out their plan for legalizing marijuana, they can look at how — and how successfully — a handful of other jurisdictions have overturned the prohibition of pot.

In 2012, Colorado and Washington became the first U.S. states to legalize marijuana. Within two years, each state set up a framework governing how retailers could start selling. 

But although the two states have much in common, they have different takes on key questions that Canada will have to consider, like whether residents will be able to grow their own plants as they can in Colorado, or whether laws should put limits on non-residents who buy marijuana here, like in Colorado — or leave the market open as Washington does.

A new study released today in the New England Journal of Medicine says the number of tourists visiting Colorado's emergency rooms doubled the first year recreational cannabis became available in the state.

The study was conducted at an urban academic hospital in Aurora, Colorado, just outside of Denver. The authors confirmed their findings using data from more than 100 other hospitals in Colorado between 2011 through 2014.

The data shows visits to the ER from out-of-state residents doubled from 85 per 10,000 visits in 2013 to 168 per 10,000 visits in 2014. ER visits for folks from Colorado stayed around the same.

For decades and until recently the science behind marijuana took place in the dark; as growers, agricultural researchers, scientists and others experimented with ways to create the heartiest and most potent strains of cannabis.

A lot of that work was, or course, kept quiet due to marijuana’s outlaw stance as well as the growers’ competitive natures.

But over the past several years there’s been a shifting of scientific research from the university lab toward legal cannabis businesses. And in one particular case that shift might bring benefits to not only the legal cannabis industry but to the broader agriculture sector as well.

BOULDER, Colorado — Humming to himself, Charles Jones makes his way up a muddy hiking trail snaking through the Colorado foothills on an unseasonably warm winter day, his colleagues Dave Georgis and David Lohndorf following close behind. Part of the way up the trail, with the city of Boulder stretched below, Jones stops and smiles at the others, then at me. “Should we do a mood?” he asks.

Visitors to Colorado are turning up at the emergency room with marijuana-related issues in higher rates than people who live here, according to a study by the University of Colorado School of Medicine.

The study, which appears in the New England Journal of Medicine on Feb. 25, found that the number of marijuana-related emergency room visits to the University of Colorado Hospital doubled among those from out-of-state from 2013 to 2014, while remaining steady for residents.

The study can’t positively peg marijuana use as the cause of the visit, said Andrew Monte, assistant professor of emergency medicine and toxicology at the CU School of Medicine.

Just 10 years ago, who would have imagined that by 2016 some form of medical marijuana would be legal in the most states in America, recreational marijuana would be legal in a handful of others, and the legalization of marijuana would be a viable issue in the presidential campaign?

OCALA, Fla. - An Ocala family has made the painful decision to pack up everything and move from Central Florida, across the country to Colorado for their young son.  They say Colorado’s medical marijuana laws play a big part in the reason why.

He’s only 5-years-old, but for a moment, put yourself in Shawn’s shoes. Being that child, is not easy. “From the time he was a month old. All we know is hospitals,” Dawn Zuzio, Shawn’s mother said. “Doctors. Specialists. Surgeries. It’s hard.”

It’s hard, Shawn’s mother said, because he lives with Chronic Lung disease, dozens of medications, epilepsy, a hole in his heart, autism, and a trachea in his throat. “The list goes on,” Zuzio said. 

Legal indoor marijuana grows are consuming energy at an exorbitant rate, according to a recent report by a cannabis industry data provider.

While most of legalized marijuana's effects on communities are measured in terms of dollars and crime statistics, electricity usage is becoming an issue of growing concern among environmentalists and industry folk alike. According to pot data firm New Frontier, the marijuana industry used over $6 billion in energy last year, or around 1 percent of the country's energy output– and that number is only expected to grow.

DENVER — Nestled between a 7-Eleven and a store selling Broncos jerseys, the door to the generic-looking retail establishment is easy to miss. But once inside, the smell is unmistakable.

At Euflora, tables are filled with glass containers of marijuana next to interactive tablets describing each strain (“sweet floral aroma,” “intoxicatingly potent”). An array of marijuana-infused products beckon behind locked cases: from energy shots to sour gummies, brownies to bacon bites. And if you’re 21 or older, it’s all legal to buy.