My wife and I just moved into a new (to us) apartment in Cambridge and, as is often the case, were faced with a hodge-podge of leftover light bulbs in the fixtures – some too dim, some too bright and glaring, some dead. All were incandescents. New bulbs went on my shopping list.

Much to my surprise, the nearby specialty food store (a high-priced place, frankly) was selling an entire pallet of compact fluorescents (CFLs), for $.99 each! All brightness levels, floods and regular, soft light and cool tones, etc. No rebates, no special incentives, no mail-in coupons, nothing. Just a rock-bottom price. How could this be?

I bought a few and found they work just fine. However, they are the kind that have to “warm up” for 10-15 seconds before reaching full brightness. Remember those?  Almost a thing of the past. Hence the low price.

This is a significant moment. We’ve been doing electric efficiency in a serious way in New England for 25 years – since CLF and others published “Power to Spare” in 1987, which predicted that we could cancel out all increases in electric demand from then until 2005 if we made basic investments in electric efficiency. Like better light bulbs. We are now many generations of light bulbs down the road (with LEDs making their presence, not to mention all sorts of CFLs). And ISO-NE is actually predicting flat growth in demand until 2021, due in part to our collective investments in electric efficiency.

But when it comes to using natural gas more efficiently, we’re still in the dark ages, and we’re faced with potentially huge growth in the use of natural gas and the pipeline infrastructure to transport it around. It’s time to apply the lessons we’ve learned in electricity to the natural gas side of the energy equation. This will save us all money and keep the environmental impacts of expanding natural gas use to the minimum reasonably necessary.

The money-saving is obvious. Just as electricity-sipping appliances may cost more in the short run but you save money in the long run, investing in more efficient gas hot water heaters and ranges, HVAC systems, and even swimming pool heating systems will save several times the money invested, over time, by using less gas.

And using less gas is obviously better than using more – reducing fracking/extraction impacts, lowering impacts from new pipeline capacity, and of course reducing GHG emissions.  A recent CLF analysis, relying on a 2009 report on the potential for natural gas efficiency commissioned by the Massachusetts state government, determined that an aggressive but reasonable level investment in cost-effective residential natural gas efficiency measures could reduce residential gas use by 30%, thereby freeing up pipeline capacity.  This also helps ensure gas will be available to heat homes in New England’s (still) cold winter, especially low-income homes, and avert the prospect of conflict between the use of gas to make electricity and using gas to keep our homes and families warm.

So, more gas? Only if all cost-effective efficiencies are achieved. And we have a long way to go get there.

And then is it OK to use more gas? Only if we use natural gas as a means to make a true transition to an electric system based much more heavily on renewables. Starting now. Natural gas should not be viewed as a “bridge fuel,” it’s a “niche fuel.” In 20 or 30 years, its niche has to be to backstop and firm up renewables, which will then be the base and majority of our electricity supply. Its niche now, to be sure, is much larger than that, as it supplies the bulk of New England’s electricity generation.

It’s cleaner than coal and oil, but it is a fossil fuel. Burning it emits carbon and that cooks the planet (and extracting it has other serious impacts). We cannot build our long-term future on a plan to extract and burn more natural gas. And if we fail to achieve efficiencies now, and build big pipeline capacity instead, we’ll be locking ourselves into that sort of future, or at least making it very, very likely.

That would be wrong-headed, and a waste. We need to get into the efficiency habit with gas as deeply as we have with electricity – so that we’ll use less of it going forward, for generations to come.

When someone offers you a simple answer to a complicated and big problem be very suspicious.

Global warming, the ultimate in complicated and big problems, can only be addressed by deploying a wide array of tools aggressively and with honest awareness of what each tool can and can not do.

Some measures, like reducing energy use through efficiency and conservation or generating electricity from the wind or from sunlight, have a clear pollution reduction effect although measuring that effect and managing those resources to ensure they are as clean, affordable and effective as possible is not simple.

Other resources can best be thought of as being a choice between “less bad options” – a powerful example of this is the discussion of the relative greenhouse gas emissions (when you look at the full life cycle of the fuel and its uses) from coal and natural gas.

A paper by Cornell University Professor Robert Howarth has started a valuable dialogue about this important topic.  For a good discussion of that paper and the responses to it take a look at the New York Times blog post and news story about it as well as coverage in The Hill (a political publication in Washington) – and you can even read the paper for yourself.  MIT’s Technology Review also offers a perspective on this study.

The paper also figured in the Senate Committee hearing about hydraulic fracturing and natural gas held this morning.  If you really have nothing better to do check out the archived webcast.

Is natural gas only half as bad as coal?  Are they comparable? Is in fact gas worse under some circumstances?  These are all important questions but overlay the critical reality that both of these fossil fuels are simply not something we can rely upon in the long term to power our societies and our economies.