Curmudgeon Alert: I'm harping on the water cycle again - its stocks, not flows - and the 'dissing' of groundwater. Here are links to three sites that form the basis of this post: USGS (groundwater), USGS (water cycle), and NGWA (groundwater use).
Mom & Apple Pie - My Bad?
I am taking The Nature Conservancy to task for promulgating misinformation. This is not an easy thing to do because I admire TNC and think it's one of the best (along with IUCN) environmental/conservation organizations in the world. TNC brags about its stellar freshwater scientists, and they are right - I know and have worked with some of them. Many of them do groundwater work - here is a great example.
I suspect their excellent scientists would not support the TNC HQ folks on this issue.
A month or so ago I received the following graphic via Twitter:
It was retweeted by a number of people I follow on Twitter. It is part of TNC's 'Liquid Courage' promotion (TNC made it easy to Tweet this graphic with a pop-up as you scrolled through the Liquid Courage site). Even Alexandra Cousteau, yes - the granddaughter of Jacques Cousteau - retweeted it.
My immediate thought: 'That figure is wrong; it is too low. I bet groundwater was neglected." I retweeted something to that effect.
TNC's 0.03% Solution: Some Perspective
Let's talk about TNC's 0.03% number. That is a very small percentage, but it is a small percentage of a VERY large number: about 321 million cubic miles or 1.34 billion cubic kilometers of water. So the amount of 'drinkable and accessible' water is about 96,000 cubic miles or 400,000 cubic kilometers. That water would comprise a cube about 46 miles on an edge or a sphere about 57 miles in diameter. Still hard to visualize? That amount of water would cover my home state of Oregon (or Wyoming, or Michigan) to a depth of one mile, or California to a depth of about 0.6 mile (3100 feet).
An aside: you should realize that all these numbers - global-scale water estimates - have a lot of undertainty in them. We just don't have these numbers pinned down with a great deal of accuracy. I tell my students +/- 10-20% (and that is itself a SWAG).
Back to 0.03% now. I know you're saying, "Wow, that really is not a lot of water for >7B people and Earth's ecosystems!" It's not - check out this great visual. However, keep in mind that the TNC figure is comprised mostly (solely?) of renewable surface water. So that 0.03% is used over and over again, although the quality can be degraded, especially after humans use it.
Nonetheless, that figure - 0.03% drinkable and accessible water - is patently wrong. It is too low. Where does that number come from? I found this on the TNC site here:
Do you know where your water comes from? Why is it important to know your water source? For starters, while water covers 70 percent of our planet, just 0.03 percent of that water is accessible and drinkable.
I also found the same thing at this TNC site. Neither site indicates the source of this figure.
A friend says the following is on the TNC site but I could not find it:
Fresh water is a scarce resource. It makes up only 1% of the world’s water. Sixty percent of that is locked up in Greenland and Antarctic ice sheets. Another 40% is in groundwater, most of which is inaccessible. By some estimates we are left with some 0.03% of the world’s water as surface fresh water [emboldening mine]. It is not scarce in the same sense that oil is scarce – it doesn’t disappear if you consume it. But, at any given point in time, there is only a very tiny amount of water that is accessible for all our uses.
So there we have it - surface fresh water! Funny but the USGS says that rivers and freshwater lakes comprise just 0.007% of total water. Upshot: I do not know where the TNC gets 0.03%, but I have seen that number elsewhere.
Drinkable and Accessible ('D & A') Water
Let's now talk about 'drinkable and accessible' water. Like TNC, I'm equating 'drinkable' with 'fresh'. Note: sustainability is not an issue in this case; check TNC's graphic - it says nothing about sustainable. Groundwater is not always used sustainably.
According to the USGS and the references cited (Peter Gleick) therein, fresh ('drinkable') groundwater comprises 46% of all groundwater, or 2.5 million cubic miles (10.5 million cubic kilometers). That is about 0.8% of Earth's TOTAL water - over 26 times TNC's number. Think I'm being too optimistic? Okay, take half the fresh groundwater (maybe half is polluted) - you're still talking about 0.4% of Earth's total water, not 0.03% - over 13 times greater.
But, you say, that groundwater is not accessible! Why not? You have to drill a well! So what - we're in the 21st century, where well drilling is commonplace. In the US alone there are almost 16 million water wells - many of those supply drinking water. That is a lot of 'inaccessibility'! Check some global groundwater use figures. If you think most groundwater is inaccessible, then you really are still dwelling in the 'mysterious and occult' realm of groundwater - from the Stone Ages.
Since we are talking about drinking water, recall that using surface water for drinking water can require dams, pipelines, treatment plants (sometimes above and beyond what groundwater might require) and all kinds of infrastructure. However, water wells can often be drilled at the point of use - where the water is actually needed, obviating the need for a lot of costly infrastructure. You don't necessarily need water districts, municipalities, etc. So an individual can also take care of his/her own water needs. The groundwater may not even need treatment. That's an accessible resource!
Why TNC Uses This Number
I don't know why TNC uses the 0.03% number and ignores groundwater. I don't even know the number's origin. I suspect it came from someone involved with marketing and fundraising. Certainly, if you are trying to impress donors with the importance of your work it would behoove you to use a small amount of 'D & A' water. The smaller the amount to be protected, the more critical your work. I understand that raising money is important. But stick to the facts, please.
And don't get me started on people who state that 'The North American Great Lakes contain 20% of the world's freshwater'. That's liquid surface freshwater, if you please.
My Ten Cents - Takeaway
TNC should quietly change the 0.03% figure or at least qualify it as ignoring groundwater. But they really should include groundwater in a new 'D and A' number. I'll go with 0.4% - conservative, in my view. I could go as high as 0.8%, but given the uncertainty in these numbers, I'll stick with the lower figure.
What I am really trying to say is that to ignore fresh groundwater is ludicrous.
If TNC wants to focus on fresh unfrozen surface water - streams and lakes - that is fine with me. If TNC does not want to acknowledge the importance of groundwater to their mission and the work of many of its experts, that's okay too. Just use the right numbers.
Doing nothing perpetuates a disservice to groundwater by marginalizing it and the people who 'do groundwater'. It exacerbates the 'out of sight, out of mind' problem groundwater faces. It is hard to get people to appreciate and protect it when they cannot see it, thereby thinking it is unimportant to the environment (think baseflow - about 30% of US streamflow) and to humans (a lot of our drinking water).
Groundwater is an important water resource. It is by far the largest liquid freshwater source and deserves to be accorded appropriate recognition.
It is not 'mysterious and occult'. TNC should just ask some of its freshwater scientists - especially those working outside the Beltway.
"Success does not consist in never making mistakes but in never making the same one a second time." - George Bernard Shaw