Roger, I found the Global Fossil Fuel consumption graph potentially confusing. It says that "Getting to net zero by 2050 requires retiring >0.05 EJ of fossil fuel consumption every day starting now". Then it equates 0.05 EJ to 9 million barrels of oil.
One is tempted (and horrified) to think we have to use 9 million boe less every day. Bu…
Roger, I found the Global Fossil Fuel consumption graph potentially confusing. It says that "Getting to net zero by 2050 requires retiring >0.05 EJ of fossil fuel consumption every day starting now". Then it equates 0.05 EJ to 9 million barrels of oil.
One is tempted (and horrified) to think we have to use 9 million boe less every day. But hang on, that would reduce our oil consumption to zero in just 11 days. Of course, what it means is we have to eliminate 9 million boe *of annual consumption* every day. That's just 25,000 boe less each day.
We consume ~100 mmb/day of oil. It's about 40% of total fossil fuel consumption.
If we reduce consumption by 9 mmb/day every day we will have eliminated oil in 11 days and all fossil fuels in ~26 days. So that can't be correct.
What went wrong? You divided the annual FF consumption by the number of days remaining to 2050. What this means is that the amount you reduce each day has to remove 0.05 EJ of the annual total. In other words, you have to reduce by 0.05/365 daily. After a year, each day's reduction (accumulated over a year) will have removed 0.05 EJ of annual consumption, which is what we want. Alternatively we want to reduce oil equivalent consumption by "9 mmboe/yr each day", not by 9mmboe each day.
It's actually clearer if we work in the same units (days) throughout.
1. in 2023, the world consumed 505 EJ of FF
2. That is 1.384 EJ per day.
3. There are 9322 days until 2050
4. We need to reduce daily consumption by 1.384/9322 = 0.000148 EJ every day
5. 0.000148 EJ = 25,825 boe
(6. Sanity check: cumulatively, 0.000148 EJ of daily consumption is 0.05 EJ of annual consumption, or 9 mmboe/year. )
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)
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.
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".
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.
Roger, I found the Global Fossil Fuel consumption graph potentially confusing. It says that "Getting to net zero by 2050 requires retiring >0.05 EJ of fossil fuel consumption every day starting now". Then it equates 0.05 EJ to 9 million barrels of oil.
One is tempted (and horrified) to think we have to use 9 million boe less every day. But hang on, that would reduce our oil consumption to zero in just 11 days. Of course, what it means is we have to eliminate 9 million boe *of annual consumption* every day. That's just 25,000 boe less each day.
Here is my math:
1. in 2023, the world consumed 504.8 EJ of FF
2. There are 9322 days until 2050
3. That is ~0.054 EJ/day needed to be retired/abated to get to net zero
4. 1 EJ = 174 mboe
5. 0.05 EJ = 8.7 mboe = ~9 mboe
First, a sanity check:
We consume ~100 mmb/day of oil. It's about 40% of total fossil fuel consumption.
If we reduce consumption by 9 mmb/day every day we will have eliminated oil in 11 days and all fossil fuels in ~26 days. So that can't be correct.
What went wrong? You divided the annual FF consumption by the number of days remaining to 2050. What this means is that the amount you reduce each day has to remove 0.05 EJ of the annual total. In other words, you have to reduce by 0.05/365 daily. After a year, each day's reduction (accumulated over a year) will have removed 0.05 EJ of annual consumption, which is what we want. Alternatively we want to reduce oil equivalent consumption by "9 mmboe/yr each day", not by 9mmboe each day.
It's actually clearer if we work in the same units (days) throughout.
1. in 2023, the world consumed 505 EJ of FF
2. That is 1.384 EJ per day.
3. There are 9322 days until 2050
4. We need to reduce daily consumption by 1.384/9322 = 0.000148 EJ every day
5. 0.000148 EJ = 25,825 boe
(6. Sanity check: cumulatively, 0.000148 EJ of daily consumption is 0.05 EJ of annual consumption, or 9 mmboe/year. )
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
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.
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".
Yes, I see your point
In the future I’ll add “annual” to fossil fuel consumption
Appreciate the close read and good math!
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.
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!
I added "annual" to the figure and replaced it. Thanks!