World Environment Day 2015, set to take place Friday, is a cause many can get behind. Global warming is regularly in the news and recent headlines suggest it shows little sign of slowing down. World Environmental Day dubs itself "the biggest day for positive environmental action," which might be needed now more than ever. Read the eight facts below to learn more about the holiday and the ways it can be celebrated.

1. The United Nations Environment Program is behind the holiday. The organization calls the holiday its "principal vehicle for encouraging worldwide awareness and action for the environment," according to the U.N. website. Every little step toward improving the environment can help, said U.N. Secretary General Ban Ki-Moon, via the holiday's website. "Although individual decisions may seem small in the face of global threats and trends, when billions of people join forces in common purpose, we can make a tremendous difference," he said.

2. The day is widely celebrated. More than 100 countries are involved in the public outreach holiday. 

3. The need for change is apparently urgent. The U.N. reports that at the current rate of population growth coupled with consumption patterns, humankind will need three planets to sustain itself by the year 2050.

4. The center of the holiday will be in Milan. The Italian city has a host of activities planned at the Milan Expo. New environmentally friendly technologies will be displayed at the expo as well.

5. Somebody made a song about the 2015 holiday. The band is called Formidable Vegetable Sound System and the song is called "Limits." It's got a lot of horn instruments and definitely has an environmentally friendly message. Two of the recurring lyrics are "get back to your garden" and "the future is yours for the choosing." The music video is below:

6. There are a ton of events in honor of the holiday in the U.S. You could find an event to celebrate World Environment Day most anywhere in the United States. The U.N. has a handy tool here that allows users to search for events by country. Events include a cleanup in Miami, an eco-friendly album release in Chicago, a camping trip in Houston and a cleanup/nature walk/spiritual experience in Los Angeles.

7. You can register your own activity. The events page is ever-growing, so if you're in the mood to celebrate World Environment Day and want to post your activity to the site, the registration form is here.

8. Past years have been a success. In 2014, the U.N. reported it received a total of 6,437 pledges and more than 3,000 activities were registered online.