A few weeks ago to help bring awareness to World Water Day, we posted an infographic in a post titled Of All The Water in the World, Just 0.08% Makes It To Our Faucets (Infographic), with the goal being to illustrate the limited amount of clean, fresh drinking water available for human use.
Unfortunately, a few aspects of the illustration and math used to create it were either confusing to readers or inaccurate. Fortunately, we have a great community of smart and thoughtful readers who pointed out some of the errors. Here's the story...A few commenters posted about problems with the math used to create the graphic. A TreeHugger reader using the handle "samfen", was the first to point out problems with the percentages, writing:
"The headline is mistaken according to the graphic, but the graphic's bizarre math makes such mistakes inevitable.
Much, much less than 0.08% of the world's water is "available for humans," according to the graphic. That seems to be the percent of *fresh water* available. But, as the graphic notes, only 0.007% of *all the water on earth* is "accessible for direct human use." So that's already ten times less than how you interpreted this.
But the graphic is terrible. First, MOST of the levels are "n% OF THAT is..." It's only the last purple level that goes back and ties the number to the percentage of all water on earth.
In short: the graphic is crap, because it applies its percentages inconsistently, and does not explain what the percentages are applied to. This leads blog writers to misinterpret it."
Touche, samfen, touche.
But thankfully samfen wasn't done and returned to point out another error in the math, which you can read about here.
Samfen concludes, "So: pretty graphics with pink and green aren't worth much if the data in them doesn't actually make any sense."
We couldn't agree more. And neither could commenter DBirdmanAR who responded to samfen with some stats from the UN Water site and made some additional points about perceived problems with the math and concluded that, "As Samfen astutely observed, the graphics & data don't work together in a meaningful way. Everyone can do a lot better than this."
Reader matthewW responded to DBirdmanAR writing that,
"It's 70%, 22%, 8% ... of 1% avail ... or 0.7%, .22%, and 0.08% of clean fresh water is available for individuals. That part of the math is fine, but poorly explained.
The leap from 30% not frozen to minus much polluted equals 1% makes the story told by this graphic very weak.
2.5% fresh * 30% not frozen * 1% clean, does equal 0.0075% of all water available ready for use, though it should be rounded to .008%. This graphic would be a stronger narrative if it didn't jump back from fresh to all water.
It's an important issue with profound facts. the story should be told better.
"This is more than a bit misleading. Water conservation is important in places with limited water resources, but places with plentiful water don't necessary need to conserve. That 0.08% of water is actually a huge crap load of water and is way more than enough for our total population. The problem is distribution. Some places have way too much water, and some places have way too little. The problem isn't the total amount of water, but getting fresh water from the plentiful areas to less fortunate areas.
All this is to say that, yes, there were clearly some serious problems with the math, the layout of the graphic failed to successfully convey the accurate information to the viewer and the copy on the post didn't help explain things very well, either.
That's why were were pleased to see that one of our favorite sites, Flowing Data, had taken note of our graphic and put out a call to their readers to help improve the illustration. In a blog post last week, Nathan from Flowing Data wrote:
"March 22 was World Water Day, and TreeHugger posted this graphic on drinking water that is available in the world. The main point is that a very small percentage of water in the world is actually drinkable. It's definitely a story worth telling, but the graphic doesn't work at all. Even as a simple presentation of percentages (from UN-Water Statistics), it's confusing.
How can we improve this graphic to tell the story more clearly? Discuss."
If you're new to Flowing Data, it is a great site to add to your reading list. On their About page they write, "FlowingData explores how designers, statisticians, and computer scientists are using data to understand ourselves better - mainly through data visualization."
We're thankful for our smart and thoughtful readers for pointing out some errors in the math and for FlowingData for taking note of our attempt at illustrating this important information. We're hoping to rework the graphic taking in some of the points from the FlowingData readers into consideration and will update our posts with the new graphic if that happens. In the meantime, we're reminded of how helpful it is to be a part of a smart and thoughtful community.
If you have additional comments on the graphic or our efforts to improve the inaccurate information, let us know in the comments below.