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If we remove 0.05 EJ of annual FF consumption each year, then we would cumulatively reduce 1.25 EJ of total consumption over 25 years, taking us from 504.8 to 503.55.

We would need to remove 0.05 EJ of annual consumption every day in order for 504.08 to get to zero in 25 years.

In 2023 the world consumed ~34,240 mboe in petroleum

That equates to a total FF energy consumption of~85.600 mboe in mboe units (i.e., =34,240/0.4)

85,600/9322 = 9.2 mboe/day reduction

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The confusion is one of units. We are dealing with a rate of consumption of 505 EJ/year. That's what we need to reduce. We need to reduce it by 0.05 EJ/year/day. That is different from 0.05 EJ/day.

In fact, 0.05 EJ/year/day = 0.000148 EJ/day/day.

0.05 EJ/year/day x 9322 days = 505 EJ/year (which is what we want).

0.000148 EJ/day/day x 9322 days = 1.384 EJ/day (which is also what we want).

Each day we must reduce *annual* consumption by 9 mmboe.

Each day we must reduce *daily* consumption by 25,826 boe.

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So to recap about my original confusion. The graph says "Getting to net zero by 2050 requires retiring >0.05 EJ of fossil fuel consumption every day starting now ... what is ~0.05 EJ ... ~9 million barrrels of oil".

The statement isn't wrong, but it doesn't distinguish between annual and daily consumption. One could erroneously take it to mean (as I initially did) "each day we have to use 9 million barrels of oil less *on that day* than we did the day before".

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Yes, I see your point

In the future I’ll add “annual” to fossil fuel consumption

Appreciate the close read and good math!

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At the risk of being picky (and I promise to shut up after this ;-) ... the other equivalent cited (1-2 natural gas plants) is not subject to the same clarification.

0.05 EJ is the equivalant of a 600 MWe gas plant running flat out for a year at 35% thermal efficiency.

So in this case it's true -- every day we DO need the equivalent of operating one less gas plant than the day before.

I can't help feeling the gas plant comparison is good, while the 9 mmboe one is bad. One is a rate of consumption while the other is a quantity (where you must chose the correct time period to convert to a rate). Putting the two alongside each other suggests (to careless minds like my own) that a gas plant burns 9 mmboe/day.

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Agreed

In previous years I used 1500 2MW wind turbines

This year I chose to use only FF

I'll think on it, and appreciate the detailed comments

Good stuff!

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I added "annual" to the figure and replaced it. Thanks!

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