Shock: “Food supply could blot out countryside, warns government scientist” > http://bit.ly/rrTZPe

I seem to have failed to get the gist of the piece across to you, which is a shame. I’ll try to phrase it differently. Let me know if this helps.

The numbers in the first third of Professor MacKay’s book all lead to the conclusion on page 103 that even if we used all of our renewable resource to its technical maximum, ignoring economic, social and environmental constraints, then it is not enough to meet our energy demand. And that (as he writes later in the book) this applies to Europe too — he writes: “Europe, like Britain, cannot live off its own renewables”.

And yet the figures on 103 are wrong — we all agree on that — you, me, David, the official statistics. So any conclusion based on them must be in doubt.

Indeed, there are plenty of reasons for doubt — because in addition to the inflated demand, the first third of the book also contains economic, social, and environmental constraints on supply, despite the statement to the contrary (I’ll write a bit more about the supply side in a new article, later). So those are not about the physics of the thing at all — they’re opinions. So, we have an inflated demand, and a set of political opinions on supply. That’s not (in Professor MacKay’s words) “what the laws of physics say about the limits of sustainable energy”.

As it turns out, Britain’s renewable resource is an order of magnitude higher than our energy demand.

And so Britain, (just like Europe and the whole world) can get 100% of its energy from renewable resources.

Now, as that’s fundamentally different to Professor MacKay’s conclusion, I think it’s pretty important. Because it means that we have very real choices about the next 40 years. We can choose nuclear or CCS as transition technologies if we want — but we don’t have to have either of them. They are only options, not necessities.

I don’t really know why I’m posting this, you’re clearly already aware of it, it’s in you graphs; I just can’t understand how you can complain about Mackay inflating his figures while also being aware that they’re lower than yours in his conclusions on pg 204. If you actually read the text on page 103 it clearly says “Now we will see if these estimates are correct”, not “so here I have conclusively proved renewables are insufficient”