Media playback is unsupported on your device Media caption Sunscreen dispensers in Miami

The sun is setting on Europe's summer, and beach bunnies and health researchers can reflect on sun safety. Did people listen to the campaigns urging them to stay safe in the sun? Or are people still convincing themselves that their lobster hue was nothing to worry about?

Global skin cancer cases are on rise, but that fact is often not enough to change people's sun-worshipping behaviour.

So how do you best persuade people to alter a habit of a lifetime?

In Florida, USA, one in five people will suffer from skin cancer. But the southern city of Miami Beach has taken a step forward in helping people to reduce their risk of getting skin cancer when out and about.

They have put 50 sunscreen dispensers out in public places, including pools and the beach with the hope that this will encourage more people to protect themselves.

Residents and tourists alike will be able to use the SPF30, UVA and UVB blocking sunscreen for free.

Officials hope that this will help to decrease skin cancer cases, though it will take months and years to see if the project has made a difference.

However, if past campaigns are anything to go by, the outlook is less than promising.

Studies show that increasing people's awareness often fails to lead to a change in behaviour. Even those dishing out the advice, such as doctors and nurses, are no better at being safe in the sun.

"There is a gap between knowledge and behaviour," explained Dr Richard De Visser, a University of Sussex psychologist who has researched health campaigns. "For example, most smokers know the health consequences of smoking - but this does not mean that they stop smoking."

But one proven way of changing behaviour is to provide cues that trigger people to make different actions.

"[The sunscreen dispensers'] visibility - even without additional messaging - could be a good cue to action," explained Dr De Visser. "If people have forgotten to put sunscreen on, or think it was too expensive to buy, then they are prompted to use it."

Fitting in with the crowd

But unfortunately, health cues aren't always effective. One study found that a shocking anti-smoking campaign backfired, leading people to smoke more.

So why don't cues always work?

These small nudges can tap into the way the human brain works using mental shortcuts - known as cognitive biases.

One such cognitive bias is called risk aversion, which brings out a strange quirk in human behaviour. People avoid risk (i.e. use sunscreen) when the benefits are pointed out to them - such as having younger looking skin. But if they're bombarded with the negatives, such as skin cancer, they are more likely to take the risk.

To see how this works on the beach, US researchers handed out leaflets to see whether subtly difference wording of safe-sun messages would influence whether people used sun cream.

As the theory suggests, they found that making people aware of the good things that could happen made them more likely to take the free sunscreen offered.

But human behaviour is complex and other factors are also at play.

Image caption Fifty dispensers have been put in public places in Miami Beach

Another big focal point of successfully changing behaviour is social norms, which can be a powerful tool.

The pressure to have a tan, or how friends and family act in the sun, will have big effects in changing sun cream use.

Projects, such as the one in Miami Beach, could make going to the beach and using sunscreen the norm, or act as a reinforcement of the right thing to do.

Slip, slop, slap

Over 30 years, investment in policy change and educational messaging has enshrined sun safe messages in the Australian psyche.

In 1980, the Australian state Victoria launched the Slip! Slap! Slop! campaign, featuring an animated seagull called Sid that encouraged people "slip on a shirt, slop on some sunscreen and slap on a hat".

The campaign has now evolved, not only delivering educational media but also ensuring SunSmart policies, such as "No hat, no play" policies in schools, are in place.

"We have seen a significant reduction in sunburn rates but also, and equally importantly, the desire for a tan in the population has reduced significantly," explained Craig Sinclair, head of the prevention division at the Cancer Council in Victoria, Australia.

Those exposed to these changes from a young age are now seeing the benefits of this behaviour. "Now, where many other Western countries are seeing increases in their melanoma rates across all age groups, in Australia by comparison, we are seeing a strong decline in younger age groups," said Mr Sinclair.

Image copyright Getty Images Image caption Australia is now seeing a decline in melanoma cases in younger age groups

But he cautions that messaging is also needed in order to have a big impact.

"In Australia it's been a multi-component approach. Not only have we been delivering the media messages, but have been working a lot in key settings such as schools, work places and sports."

So what does this mean for the Florida project?

Dr De Visser says: "We often want to have the simple explanation of whether health campaigns will or won't work, but it doesn't always work that way.

"Certain factors work for certain people at certain times. But the programme should result in at least some people increasing their use of sunscreen.

But he adds: "At the end - only time will tell."