Over the weekend, a challenge issues in a post on Reddit (on r/wholesomememes to be exact) has gone viral and, as befitting the subreddit's name, the challenge is a wholesome one.

Have you been on social media and noticed a surge of before and after photographs of public spaces cleaned up by the individuals on the photo? You're not alone! This is the #trashtag challenge, which went viral over the weekend, especially on the forum Reddit and other social media spaces such as Twitter and Facebook.

The challenge's premise is simple: post a before picture of a beach, path, or otherwise space in nature, and then post an after photo with all the bin bags you've used to clear the debris from the area. The challenge varies in scale - after all, every little helps, as goes the slogan of a popular UK supermarket. Other examples show the dedicated work over months and even years in clearing beaches riddles with plastic.

So where did the challenge start? With the above post on r/wholesomememes. The above screenshot alongside its call to action showed the striking difference an individual or a few individuals can make in taking some time to clear up an area of nature that has suffered from a culture of littering.

The post then led to a number of people posting their contributions on many social media outlets, including different subreddits and of course, on Twitter. Below are a few of the striking images that show the difference the dedication to cleaning up litter can make to the earth's natural spaces.

Obviously the challenge is not limited to millennials and teenagers, but it is refreshing to see a viral trend be overwhelmingly positive and make a difference.