Climate Change: Reduced demand for heating to be offset by air conditioning demand.

[NNadir]

We hear all the time about climate change feedback loops. For instance here at E&E, we are often alerted by Hatrack and others about the release of methane from the Siberian, Alaskan and Canadian tundra, a mechanism that, of course, accelerates the warming of earth's atmosphere.

Some feedback loops though, are negative. I have personally wondered, without any real information, about whether the number of warm days in winter would lead to a reduced demand for energy, owing to a reduced need to heat homes that burn fossil fuels and forest.

An article recently published in Geophysical Research Letters (GEOPHYSICAL RESEARCH LETTERS, VOL. 33, L17703, September 2006, entitled "Responses of energy use to climate change: A climate modeling study" published by scientists at Oregon State and at Argonne National Laboratory (Stanton W. Hadley, David J. Erickson III, Jose Luis Hernandez, Christine T. Broniak,
and T. J. Blasing) suggests that in fact climate change will increase the demand for energy.

Some excerpts, beginning with the abstract:

Using a general-circulation climate model to drive an energy-use model, we projected changes in USA energy-use and in corresponding fossil-fuel CO2 emissions through year 2025 for a low (1.2
C) and a high (3.4
C) temperature response to CO2 doubling. The low-DT scenario had a cumulative (2003 – 2025) energy increase of 1.09 quadrillion Btu (quads) for cooling/heating demand.
Northeastern states had net energy reductions for cooling/heating over the entire period, but in most other regions energy increases for cooling outweighed energy decreases for heating. The high-DT scenario had significantly increased warming, especially in winter, so decreased heating needs led to a cumulative (2003–2025) heating/cooling energy decrease of 0.82 quads. In both scenarios, CO2 emissions increases from electricity generation outweighed CO2 emissions decreases from reduced heating needs. The results reveal the intricate energy economy structure that must be considered in projecting consequences of climate warming for energy, economics, and fossil-fuel carbon emission...

...While end-use energy changes show the direct impact of temperature changes, the change in primary energy (which includes the large thermal energy loss during electricity generation) is more important from the standpoint of emissions. Since electricity is used more for cooling than heating, primary energy (generated from coal, oil, gas, nuclear reactors, or renewable sources) will change by a different amount than will the end-use energy requirements. <11> Changes in heating and cooling degree days from long-term averages used in the reference scenario will vary...

...4. Fossil-Fuel Carbon Emissions

<13> Changes in national energy use will affect fossil-fuel carbon emissions (as CO2) to the atmosphere. Projected emissions departures from our reference scenario for Highand Low-DTscenarios are shown in Figure 3. In the Low-DT scenario, primary energy use increased in the latter years leading to an increase in projected USA fossil-fuel carbon emissions. In the High-DT scenario, projected carbon emissions increased as well, although total energy use decreased in most years due to greater warming during the winter months. Carbon-intensive coal use for electricity generation increased while other fuels declined, so net carbon emissions increased despite reduced overall energy use. Although the projected peak increase of 9.4 Tg of fossil-fuel carbon emissions in 2023 represents 0.43% of total USA fossil-fuel carbon emissions projected for that year, the increasing tend could become more significant in succeeding years...

...Our preliminary analysis provides insights into the interplay between climate change, energy use, economics and fossil-fuel carbon emissions. Cooling is less energy efficient than heating, so an increase in cooling needs (and associated fossil-fuel carbon emissions) can more than offset an equal decrease in heating needs (and associated fossil-fuel carbon emissions). Moreover, coal is more carbon intensive than other fossil fuels, so increased use of coal-derived electrical energy would further amplify carbon emissions. Regional analysis shows increases, or very small changes, in energy for space cooling/heating in the southern and western regions of the USA, while some northern regions have energy and cost savings, and corresponding decreases in fossil-fuel carbon emissions even without mitigation efforts.

The big word in this article is coal.

My often stated opinion is that coal needs to be banned, starting now. It is unacceptably dangerous.

[Porcupine]

1. Conserve instead. Improve/swap out inefficient AC units.

Ground loop heating/AC units use considerably less energy than anything but conservation. Once densities are up to the townhouse level thermal sinks could become a funtion of public utilities or HOA's.

These systems use 1/3 the power of new HVAC units. Replacing the millions of beat up AC units in rentals and instituting mandatory thermal upgrades for all residential properties as a condition of utility service would also save energy.

All of this can be installed with very little lead time.

[NNadir]

3. Of course there is a greenhouse gas cost with buying all new consumer stuff.

Just imagine the climate cost of driving millions and millions of trucks around buying more stuff.

Personally - I could be wrong on this - a real solution here would involve slowing greenhouse gases in the first place, not merely accepting climate change and buying all new air conditioners.

Having a consumerist orgy under circumstances where effectively nothing is done about climate change is not likely to be affordable.

[YankeyMCC]

2. When I worked for a municipal power company

It was always the summer that concerned us in terms of being able to met demand not the winter.

Much to the consternation of my wife I've resisted putting A/C in our home (we live in New England and for the last 8 years have managed with strategically placed fans :) )

One nice thing about my stubbornness is my son has never known what it's like to live in a home with a/c (except for when we lived in VA when he was an infant) so I don't think it bothers him as much as my wife and perhaps it'll instill a similar mind set as me about the need for (or lack thereof) A/C in a New England climate.

[NNadir]

4. I have one, and I admit I have used it. However tall trees shade

my house. I probably run it much less than a quarter of the summer.

[AZCat]

5. So do I - a crappy split-system heat pump.

I live in a condo and it came with the place, but I use it rarely (mostly because I'm not here during the day). Unfortunately my behavior is not typical, and as the poster above said, our power system here in Southern Arizona is driven by peak demand - a number that during the summer is about double the average. Our problem is twofold - conservation (shutting the damn things off occasionally or perhaps using more efficient units) and population. The conservation side is getting a little better - the Pima County government (Tucson area) is adopting the 2006 International Codes in January and they include some pretty strict energy efficiency requirements - but our population continues to grow rapidly, although perhaps not as quickly as Maricopa County (Phoenix area).

[phantom power]

6. I have a feeling that there is only one really significant negative feedback.

That would be climate change killing many, many people.

[NNadir]

7. Well it is certainly one possibility that deserves consideration. n/t