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Retro: The Kaya Identity and the "Conservation Bomb"

The interplay between energy use, carbon emissions and global warming is one of the cornerstone issues we discuss. One of our main arguments about climate disruption is that there won't be a single, "silver bullet" solution. Instead, in order to avoid the worst effects of global warming, we will need to address energy production, carbon mitigation and -- critically -- efficient consumption of power. In June, I took a look at the "Kaya Identity," a formula showing the carbon results of changes to population, GDP per capita, watts per dollar, and CO2 per watt. Both efficiency -- decreasing the watts required per dollar of GDP -- and clean energy -- decreasing the CO2 per watt -- are good ways of avoiding disastrous scenarios. The effects of shifting to non-carbon energy sources are pretty well understood, but the value of greater efficiency can be quite surprising. Efficiency is, in a word, worldchanging.

So -- without changing any other values -- if we alter the Watt/$ reduction box in the Kaya Calculator from -1% to -2%, something very interesting happens. Instead of needing 17 terawatts of carbon-free power to stabilize at 450ppm in 2100, we'd need 4 TW. That's not 4 terawatts out of ~50, either; that's 4 TW out of about 18 TW, because the boosted efficiency has reduced the overall consumption.

Comments (10)

We had a long discussion on energy intensity and problems with such arguments last time on this one...

Anyway, the main point is, you don't get something for nothing here: altering "-1%" to "-2%" improvement in energy intensities would in practice be very very hard, perhaps impossible. Because it means that, over that period of time, we have to improve energy efficiency by exactly that factor of 3 or so (from 50 TW to 18 TW) BEYOND the natural improvement that the "-1%" represents already over the time period. Energy efficiency improvements of a factor of three or more may be available in some areas (lighting, for instance) but a factor of 3 beyond natural improvement is very unlikely to be available anywhere.

And we still need 4 TW of carbon-free power even with that; why not go for the whole 50 while we're at it, or even more?

Daniel Haran:

I think the "burden of proof" in this debate now belongs squarely to those who don't think it's possible.

Work by the likes of Amory Lovins and the RMI has given several examples of areas where we can achieve dramatically more efficiency.

It will be interesting to see in the next few months how much people and especially corporations change their behaviour.

Another "retro" discussion applies: if our political economy remains designed for exponential growth, no amount of efficiency gains will save it. The fundamental task is to reorient from growth to sufficiency. As always, "growth" is different than "development." We can probably "develop" forever, but we can't "grow" for much longer at all. If we abandon growth, efficiency stands a chance. Not otherwise.

Virtually no one wants to accept this. We're embedded in, and addicted to, growth. If someone could distinguish growth from development in a way that people could hear and accept, that alone would be very world-changing.


The reason growth is key in america is eventualy we will have at least a billion people here and unless we grow our econ and everything else we will be crushed by the weight of its impact. Unless we get a hell of alot more economic might we wont be able to build the mega cities we will need to house them all.

Human primary energy supply is about 12 to 13 TW (Terrawatts). Of this, the U.S. uses about 3.3 TW.

One TW of non-carbon energy would require:

- 1000 1-Gigawatt nuclear power plants;
- A breakthrough in fusion, with construction following;
- Carbon sequestration on a scale no one has described;
- 1,000,000 3-Megawatt wind turbines (since wind varies);
- about 10,000 square miles (25,900 sq. km.) of PV;
- about 1/7 of U.S. land area for biomass;
- not-yet-proven, not-yet-developed ideas.

(See Hoffert et. al., "Energy for a Greenhouse Planet", "Science" Vol. 298. pp. 981-987, Nov. 2002.)

At today's prices, 1 TW of photovoltaics would cost approximately $11 trillion. (Of course that will change, but there's no guarantee the price will fall - in fact, the price of high-quality silicon has jumped dramatically this year.) Total U.S. GDP in 2004 was about $11.9 trillion (CIA World Factbook).

Merely replacing our current energy use is a mind-boggling task. Under the "2% Solution" Jamais presented in this piece, we would need at least 4 TW of non-carbon energy, with total consumption of 17 TW. And many are doubtful that the 1% trend could be elevated to 2%.

This assumes continued growth of the resources and energy required by human beings.

That assumption, I humbly submit, is nuts.

A guy named Herman Kahn wrote a book called "Thinking About the Unthinkable." It was about using nuclear weapons. It wasn't a good book, but it had a catchy title.

We need to think about the unthinkable a lot now. Nothing's off the table: geo-engineering, nanotechnology, tabletop fusion, gene splicing, a participatory noosphere - all real possibilities.

So are runaway climate chaos, global pandemics, mass extinctions, mutated gene pools, fractal warfare and stuff we can't even imagine.

So let's think about another unthinkable: that we humans have grown enough, used enough land, water, energy and resources, reproduced enough, taken our fair share. In fact, we've overdone it, had a few too many, need to sober up a bit. We'll have a transition time, of course - but we'll transition to lives with more meaning, less stress, more justice, less cruelty, technologically more elegant, psychologically more rewarding, materially less wasteful and self-indulgent. A world where frugality, patience and kindness are virtues and the worst sins are hubris, impatience and greed.

Let's think about that. It's hard, but it sure beats the alternatives.


Well first off we have to assume some more coal plants will be built as they are by far the biggest power plants on earth. A large scale coal plant can generate 50-75 gws of power thats why they are soo polluting they are MASSIVELY powerful machines.

I expect 10 more coal plants for about 400-600 gws of power.

So we need 600 to 400 gw more power.

100 4 reactor nuke plants will do it. Or a combo of fewer of those and alot of 5 mw wind turbines and various solar and wave plants.

Now yes if they scrub co2 from the coal smokestacks and pump it via pressurized liquid co2 pipeline they might need an 11th coal plant to provide the same power output. But its very doable.

David Foley (above) is right to note the challenges - I've discussed this a lot with Marty Hoffert who he quotes. But if we're thinking about the unthinkable, why trot out numbers like $11 trillion as if that was a real obstacle?

* This year the US will spend over $750 billion on oil and gas, over a trillion dollars on energy, in one year alone.
* Solar, wind, and most other renewables have high capital costs, but should have very low maintenance costs over their 30+ year life-spans: the $11 trillion for one TW of solar now is "only" $370 billion/year, spread over 30 years.
* Solar panels don't have to use much silicon (new thin-film and non-Si technologies); silicon is also the second most abundant element on Earth's surface (oxygen is number 1) so there's no way we'll run out of it; constraints on supply right now are temporary manufacturing issues at worst.
* There are several studies out there all projecting a steady improvement in solar panel pricing with economies of scale and new technologies coming on board.

Solar has far more room to grow into an economic solution than anything else. Scalability goes even beyond Earth's surface: the Sun produces an awful lot more energy than our planet ever sees. 50 TW or more is perfectly feasible in the long run. There are real solutions here; let's try them!


Nuke power can power cars IF batteries get that last bit along. Even if they cant that way type 4 nuke plants will provide alot of hydrogen which we will need even if we dont use it for cars as its needed to make fertilizer.

Anyway as we are actauly gona avoid climate change and global warming as its already far too late to stop the shift im not exactly bothering with the item of going carbon neutral quickly.

China will burn all the oil and coal it can get india will too. Various other nations will do the same so frsnkly that fight is hopeless and its best to plan for the future expecting it.

Daniel Haran:

Until this article, I didn't realize just how much impact efficiency could have. Thanks Jamais!

This is extremely encouraging. 3% should be possible, and meanwhile wind and solar keep falling in price.

I'm not concerned about the limits to efficiency, because we always seem capable of pushing them back. There are easy gains in fuel efficiency- but we know already that greater gains are to be had in city planning (reducing the trips that are necessary).

Trains are better than trucks, and sometimes we can even avoid having to transport goods in the first place. By buying and producing more durable goods we don't have to be shipping them across the world as often. Local production with decentralized design would make shipping increasingly unnecessary.

Point is- we could become radically more efficient while changing the goal posts. We'll never break the laws of thermodynamics, but we can't ever lose track of the fact that people still want hot showers and cold beers, not kilowatts. If you're still a skeptic, please browse Natural Capitalism (the entire book is available for free online).


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