Does saving energy save the climate?

December 17, 2018, ETH Zurich

To stop climate change, saving energy matters less than switching to renewable energy. Indeed, says Anthony Patt, it isn't clear whether saving energy makes much of a difference at all.

During the summer heat wave of 2018, the Swiss media reported that the elderly in particular were suffering. In order to achieve climate policy goals, it was impossible to turn on air conditioning in Zürich homes for the elderly. Reducing energy consumption is good. But does climate protection demand that people suffer, especially the elderly, when temperatures rise?

The standard answer seems to be yes. The logic is simple: most of the energy people use comes from , which are the main cause of climate change. So it would seem logical that people need to use less energy.

But there is an important omission in this logic. It stems from the fact that to stop climate change, we need not just to reduce our CO2 emissions, but rather to eliminate them entirely. Once none of our energy comes from fossil fuels, then energy use will be irrelevant.

Of course this isn't the entire story either. It will take time before we can switch to entirely , across all sectors of the economy. So there are two more important questions worth investigating:

First, does the energy we save during this period of transition to purely renewable energy make much of a difference?

Second, will efforts to conserve energy also accelerate the shift to renewable energy, or could they even slow this shift down?

A drop in the ocean

We recently examined the first of these questions. The short answer: saving energy makes almost no difference. To meet the targets that scientists and policy-makers have set – limiting climate change to less than 2°C total warming – we need to eliminate emissions in the next 20 to 30 years. The exact deadline for going fossil-free depends on a number of uncertain factors, most importantly whether we believe it will be possible to actively remove CO2 from the atmosphere in the second half of the century.

The climate turns out to be remarkably insensitive, however, to changes in . Under one set of assumptions, which includes current trends in improving energy efficiency, the deadline to go fossil-free is 25 years from now, 2043. With a great deal of effort, we could double the rate of improvement in energy efficiency, from the current trend of 1.5% improvement per year to 3%. How much would that shift the deadline? Only one year, it turns out, moving it from 2043 to 2044. Saving energy buys us almost no time.

Unclear effect on transition

What about the second question: will saving energy make it easier or harder to go fossil-free in such a short amount of time? The short answer is that we don't really know. There are arguments going in both directions, but little in the way of any hard evidence. There is more than enough wind and sunshine available to completely replace the fossil fuels we currently use.

One argument supporting energy efficiency is that the less energy we use, the less renewable energy infrastructure we will have to build, and that will make the transition go faster. In some cases there are clear synergies. Electric cars, for example, are far more energy efficient than gasoline or diesel models; at the same time, they make it possible to drive with power generated from the sun, wind, and falling water. Similar synergies can be found comparing electric heat pumps to oil and gas heaters.

On the other hand, there is reason to believe that the investment climate will be more conducive both to innovation, and to building the needed infrastructure, if overall energy demand is growing, or at least not shrinking too fast. Indeed, there are some cases where using more energy could be helpful. In one study, for example, we found the future costs of integrating large amounts of solar into the energy system to be far less if we assume that future electricity demand is highest in the summer, rather than in the winter. That happens when people use air conditioning.

Of course, there are a lot of reasons to save energy. But we don't stop climate change by using less energy—we stop by using different energy.

Explore further: Widespread decrease in wind energy resources found over the Northern Hemisphere

More information: Huber, M. Senioren leiden in Zürcher Altersheimen für den Klimaschutz. Tages Anzeiger (13.10.2018).

Anthony Patt et al. Will policies to promote energy efficiency help or hinder achieving a 1.5 °C climate target?, Energy Efficiency (2018). DOI: 10.1007/s12053-018-9715-8

Pfenninger, S. et al. Potential for concentrating solar power to provide baseload and dispatchable power. Nature Clim. Change 4, 689–692 (2014).

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6 comments

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StupidNet
1 / 5 (6) Dec 18, 2018
Ok - somebody show me where we can create energy and NOT use fossil fuels. Since mining, processing, manufacturing, assembly, distribution, shipping and repair are still ALL done with fossil fuels for "alternative energy" materials - PROVE to me that we can create energy NOT using fossil fuel.

Personally, I think every article, researcher, scientist, etc., lies about this overlooked fact. We will NEVER have energy without fossil fuel somewhere in the pipeline (we don't know how to use photosynthesis yet as a primary energy source). Solar, wind, hydro, geothermal, wave, hydrogen, nuclear - it all requires enormous amounts of fossil fuel to mine, processing, machine, manufacture, distribute, ship, install and repair. Therefore - we will NEVER be "emissions free" from fossil fuel, ever. Unless we go back to the Stone Age (no power).
Da Schneib
3 / 5 (2) Dec 18, 2018
It depends on the source of your energy.
granville583762
3 / 5 (4) Dec 18, 2018
Global Warming - Not Climate Change

Twas brillig and the slithy toves
Did gyre and gimble in the wabe
All mimsy were the borogoves
And the mome raths outgrabe
Beware the Jabberwock my son
The jaws that bite the claws that catch
Beware the Jubjub bird and shun
The frumious Bandersnatch

This Jabberwocky that twas climate change
Tis now the frumious Bandersnatch
As climate change tis twied to dioxide twixed carbon

This Jabberywocky was heat produced by burning fuel
That with renewables this heat is produced by moving electrons
The true aim of global warmists is coming crystal clear
To keep mankind in Stone Age
Even when fusion is realized
Even when energy is limitless
Even when energy is free
These global warmists are advancing forces
They are protecting the Cause
They are digging there redoubt
Energy is the new climate change these global warmists
These new age eco warriors
Are the frumious Bandersnatch

Beware this frumious Bandersnatch
Bert_Halls
4 / 5 (4) Dec 18, 2018
I have a sufficient rejoiner to granville's atrocity:

Go fuck a cactus, you shitstain.
Bert_Halls
4.2 / 5 (5) Dec 18, 2018
Oh, and stupidnet, that explains why horses remain, to this day, the foundation of the American economy.

You earfucking dumbshit.
granville583762
3.4 / 5 (5) Dec 18, 2018
Beware frumious Bandersnatch

Energy in our galactic solar system
is free and endless
it does not go any where
it is always there
even when it is all used up
as it kept the earth warm before we used this energy
as we used this energy up
as it returns to earth
just as dust to dust
ash's to ash's
this earthly heat that our sun heats our earth
we extract
with solar panels
on using up this energy
as in our cup of tea
the energy of heat
leaves our bodies and returns to heat the earth
as this cup of tea
if we had not intervened with solar panels
this Sun
this golden orb
would have warmed this earth directly
So be warned boys and girls
These global warmists are the frumious Bandersnatch

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