Climate change is taking center stage during the Olympics this year, but global warming is making fewer cities suitable to host, leading to an uncertain future for the Olympics.

Before the Rio Olympics' opening ceremony, dozens of athletes and thousands of spectators decided to skip the Olympics citing concerns over the Zika virus, which has been shown to thrive in the warmer, wetter conditions brought on by climate change.

Summer Olympics

A new study published this year shows that by the 2084 Olympics, rising temperatures will make it practically impossible for most cities to host the Summer Olympics.

With only eight Northern Hemisphere cities outside of Europe will be cool enough to host the games, with only three cities in North America capable of serving as hosts, the future of the Olympics isn't just uncertain, it is inevitable.

The researchers arrived at this conclusion by developing a measurement, called the wet bulb global temperature (WBGT), that combines temperature, humidity, heat radiation, and wind. This tool was used in conjunction with two climate models to assess the viability of future host cities.

The researchers acknowledge that there are a number of workarounds, such as eliminating certain events, that would allow the Summer Olympics to continue, but they would look very different than they do in Rio.

Winter Olympics

In 2014, before the Winter Olympics commenced in Sochi, Russia organizers and athletes wondered whether or not there would be enough snow for the games to take place. Sochi ended up being one of the warmest Winter Olympics ever.

"Right now, all of the past host cities were deemed climate reliable," said Daniel Scott, the Canada Research Chair in Global Change and Tourism at the University of Waterloo, has been studying the relationship between sports, recreation, and the environment for a couple of decades. "But by midcentury, that number drops to about half, and by late century, under the warmer scenarios that number is down to as few as six."

In a worst-case scenario with emissions, by 2080 more than half of the last 20 Winter Olympics would not be climatically viable. Meaning there would not be enough snow for events or the temperatures would be too high to even compete.

Athletes at the Olympics

Having endured two straight Olympics with warmer-than-ideal conditions, athletes are starting to worry publicly about the future of their respective sports, releasing a statement in partnership with the climate change advocacy group Protect Our Winters.

Andrew Newell, the American cross-country skier who penned the petition, wrote, "Snow conditions are becoming much more inconsistent, weather patterns more erratic, and what was once a topic for discussion is now reality and fact. Our climate is changing and we are losing our winters."

As we enter the second week of the Rio Olympics, the uncertain future of the games should motivate us to take action on climate change.