In honor of Earth Day, RedTube is giving out a week of free porn. But there's a catch: You have to save water first.

Access to clean water is something that many of us take for granted. According to the United Nation's 2018 World Water Development Report, more than 2 billion people don't have access to safe drinking water, and another billion are expected to lack clean water by 2050 because they live in "potentially severely water-scarce areas." Twenty percent of the global population's access to clean water will be limited by 2050 because of contaminated supplies in flood-prone areas.

The thirst is real. Literally.

And saving water isn't easy — although awareness campaigns like World Water Day outline big-picture solutions, it's difficult to commit to individual efforts to conserve water.

What better motivation is there to save water than a free week of premium porn?

RedTube hopes to encourage people to think about the water crisis with its "Save Water Challenge." An app available on Google Play — and out soon on iOS — tracks the length of your daily showers. The shorter the shower, the more points you'll get. If you meet a certain number of points, RedTube will award you with a week of its premium subscription so that you can watch all the porn you want — for free!

For every five minutes of running water you cut from your shower, you save 100 liters of clean, drinkable water. So while you're rubbing one out, give yourself a pat on the back for saving the world! Conserving water is so easy, you could do it with one hand.