Charlotte McDonald
speaker
483 appearances
11 recordings
2 series
first heard Feb 2012
last heard 11 Jun
Charlotte McDonald’s voice in public audio — every appearance, attributed to the second.
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recordings per month · last 12 monthsRecordings per month over the last 12 months — 5 in all, peaking in May 2026 with 2.
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More or Less · Does it take 15,000 litres of water to produce a kilogram of beef? · 2 May 2026
podcast
He developed a method for figuring out how much water a food crop or animal used, wherever it was in the world.
But to point out the obvious, not all parts of the world are arid drylands where there's little to no rain.
In this case, if you think a higher water footprint is a bad thing, then you'd be saying that chopping down rainforests for coffee plantations is good.
What's more, the water we're talking about falls as rain.
And to put it mildly, rain is not in short supply in a rainforest.
This is Tim Hess, a professor of water and food systems at Cranfield University in the UK.
Green water is rain.
Blue water is pumped out of rivers and lakes.
There's a third category, grey water, which is the water that's needed to dilute any pollution, like fertiliser runoff.
Right, back to the beef.
If we look at beef production and this 15,000 figure... The majority of the water is associated with producing feed.
In the UK, cows mostly stand around in fields eating grass.
That grass gets its water from rainfall.
The different methods of farming make a massive difference to the amount of blue water you have to pump out of rivers, lakes and aquifers to produce the cow food.
That figure we're looking at, that 15,000 litres of water are needed for each kilogram of beef, includes all types of farming and all the types of water.
It's a weighted average of the water use across all the different beef production systems the researchers analysed.
And 94% of that figure, more than 14,000 litres of water, is green water.
It's rain falling on grassland or other crops.
This, says Tim, makes it pretty useless if you're using the number to think about how good or bad eating beef is for the environment.
As with coffee in the rainforest, it's unclear whether it's a good or bad thing.
Showing 61–80 of 483 · page 4 of 25
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