I. Doubling is not dramatic:
Doubling of energy supply is not a dramatic increase in at least two ways:
It looks quite conservative when considering the demographic and economic dynamics you mention (60% population increase, hopefully at least a tripling in GDP per capita, i.e. something like a 5x larger economy). Saying one expects energy demand to only double by end of century assumes a lot of reductions in energy intensity, i.e. increased efficiency, structural change, and, possibly, demand reductions.
Relatedly, it is by far not the at the upper end of plausible futures the IPCC and many other bodies consider. Indeed, it would not be terribly surprising if energy demand by end of century increased by much more than just a doubling and this is something our responses should be robust to.
II. Carbon intensity of energy to ~0 is the sine qua non of climate success.
Per the Kaya Identity, the only way to get to zero emissions is when the carbon intensity of all economic activity is zero, it’s the only necessary condition and it’s also sufficient. Because there is also carbon removal and the goal is net-zero not zero it’s not quite as logically necessary (though it’s still sufficient).
Quick reply from me too—You’re right, doubling isn’t so dramatic so I’ll amend that sentence. What I really meant to say was that we have to scale up our low-carbon energy production from roughly 17,500 TWh in 2020 to 308,000TWh in 2100, an increase of almost 17x, which seems more dramatic to me! Will reply to the following later.
This also strikes me as pretty relevant in this context, essentially the IPCC’s scenarios do not include futures where energy demand does not increase and a doubling (compared to 2010) is roughly in the middle of considered scenarios (of course, this is very simplistic, not all of those scenarios are equally plausible, nor does the IPCC necessarily capture the entire range of possilble futures, but it gives a good sense of how unlikely a scenario such as the one the paper you cite uses is in the overall range of views).
Q1: In a world where a focus on lifestyle advocacy makes a large difference to emissions (i.e. is cost-effective), I am fairly unconcerned about climate—this is not a world with a lot of climate risk. Conversely, in the worlds where most of the risk is—high growth pressures and low willingness to pay for climate—such a strategy will not be cost-effective whereas a strategy focused on making low-carbon energy the option of choice irrespective of concern about climate will (what I called the “shit hits the fan principle” in the GWWC talk).
Q2: We know that there is at least one energy source that could reliably and sustainably power civilization for centuries (nuclear fission) and likely there are several more (solar, nuclear fusion, advanced geothermal). This mostly seems a problem if one wanted to power the entire civilization only with intermittent renewables in their current state (e.g. without them becoming more resource-efficient).
I’ve worked in energy efficiency, so I’ve thought about this a lot. Pure energy efficiency is getting the same utility with less energy. However, energy conservation is generally regarded as situations where you have to give something up, such as thermal comfort, convenience, travel, second homes etc. One successful example of energy efficiency is appliances in the United States such as clothes washers, refrigerators, and dishwashers now use about 1⁄4 as much energy as they did a few decades ago at negative costs for CO2 saved. I think there are still many opportunities to reduce energy use cost effectively and get the same utility. But once you go to non-cost-effective energy efficiency or directly limiting activities, the economic costs (taking into account non-monetary factors) get extremely high. I’ve run a few numbers and have gotten around $1,000 to $10,000 per ton CO2, versus ~$100 per ton CO2 for things including renewable energy and air capture. So I don’t think we should be directly limiting activities.
Thanks, James!
More on this later, but for now just two points:
I. Doubling is not dramatic: Doubling of energy supply is not a dramatic increase in at least two ways:
It looks quite conservative when considering the demographic and economic dynamics you mention (60% population increase, hopefully at least a tripling in GDP per capita, i.e. something like a 5x larger economy). Saying one expects energy demand to only double by end of century assumes a lot of reductions in energy intensity, i.e. increased efficiency, structural change, and, possibly, demand reductions.
Relatedly, it is by far not the at the upper end of plausible futures the IPCC and many other bodies consider. Indeed, it would not be terribly surprising if energy demand by end of century increased by much more than just a doubling and this is something our responses should be robust to.
II. Carbon intensity of energy to ~0 is the sine qua non of climate success.
Per the Kaya Identity, the only way to get to zero emissions is when the carbon intensity of all economic activity is zero, it’s the only necessary condition and it’s also sufficient. Because there is also carbon removal and the goal is net-zero not zero it’s not quite as logically necessary (though it’s still sufficient).
Quick reply from me too—You’re right, doubling isn’t so dramatic so I’ll amend that sentence. What I really meant to say was that we have to scale up our low-carbon energy production from roughly 17,500 TWh in 2020 to 308,000TWh in 2100, an increase of almost 17x, which seems more dramatic to me! Will reply to the following later.
This also strikes me as pretty relevant in this context, essentially the IPCC’s scenarios do not include futures where energy demand does not increase and a doubling (compared to 2010) is roughly in the middle of considered scenarios (of course, this is very simplistic, not all of those scenarios are equally plausible, nor does the IPCC necessarily capture the entire range of possilble futures, but it gives a good sense of how unlikely a scenario such as the one the paper you cite uses is in the overall range of views).
https://www.sciencedirect.com/science/article/pii/S0959378016300681
On your questions more directly:
Q1: In a world where a focus on lifestyle advocacy makes a large difference to emissions (i.e. is cost-effective), I am fairly unconcerned about climate—this is not a world with a lot of climate risk.
Conversely, in the worlds where most of the risk is—high growth pressures and low willingness to pay for climate—such a strategy will not be cost-effective whereas a strategy focused on making low-carbon energy the option of choice irrespective of concern about climate will (what I called the “shit hits the fan principle” in the GWWC talk).
Q2: We know that there is at least one energy source that could reliably and sustainably power civilization for centuries (nuclear fission) and likely there are several more (solar, nuclear fusion, advanced geothermal). This mostly seems a problem if one wanted to power the entire civilization only with intermittent renewables in their current state (e.g. without them becoming more resource-efficient).
I’ve worked in energy efficiency, so I’ve thought about this a lot. Pure energy efficiency is getting the same utility with less energy. However, energy conservation is generally regarded as situations where you have to give something up, such as thermal comfort, convenience, travel, second homes etc. One successful example of energy efficiency is appliances in the United States such as clothes washers, refrigerators, and dishwashers now use about 1⁄4 as much energy as they did a few decades ago at negative costs for CO2 saved. I think there are still many opportunities to reduce energy use cost effectively and get the same utility. But once you go to non-cost-effective energy efficiency or directly limiting activities, the economic costs (taking into account non-monetary factors) get extremely high. I’ve run a few numbers and have gotten around $1,000 to $10,000 per ton CO2, versus ~$100 per ton CO2 for things including renewable energy and air capture. So I don’t think we should be directly limiting activities.