In February, Dr Matt Prescott used the Green Room to call for the traditional light bulb to be banned. This week, he responds to some of the comments and questions raised by readers.
One of the reasons I proposed the eventual banning of incandescent light bulbs was that the phased ban of chlorofluorocarbons (CFCs) worked extremely well when it was used to tackle the hole in the atmosphere's ozone layer.
Today, nobody misses CFC-based aerosol technology or even notices that other technologies have taken their place.
When applied to incandescent light bulbs, I had no idea what the response would be to the idea of taxing, phasing out and banning another cheap and familiar technology.
Especially when this technology was more indirectly responsible for altering the composition of the Earth's atmosphere, and there was more complexity and uncertainty associated with understanding, and tackling, climate change.
According to the feedback I have received, some people have changed all the bulbs in their houses and said they will never look back.
Others have said that their light bulbs don't waste energy, but help to heat their houses, or that an energy-saving light bulb cannot be used with a dimmer switch.
Here, I will attempt to address these and other points.
Energy-saving light bulbs have been available for 30 years, and although they are quick and simple to use, require five times less electricity to do much the same job, cut greenhouse gas emissions by 60-70% and save users approximately £7 per bulb each year, they have not caught on.
In the UK alone, it has been estimated that the use of energy-saving light bulbs, in suitable applications, would reduce the amount of carbon dioxide released into the atmosphere by 2.3 million tonnes per year (2.3 Mt CO2).
Such an annual saving would be equivalent to 8-21% of the emissions reduction the UK government has stated that it wants achieved by 2010.
Similarly, across Europe, new domestic, business and street lighting technologies could help to reduce greenhouse gas emissions by 24 Mt CO2.
Part of the problem is that incandescent light bulbs have undergone 100 years of mass production and refinement, and now enjoy a large purchase price advantage over their energy saving equivalents.
The traditional focus on purchase price is very misleading; however, as the total cost of using such a wasteful technology is much higher than any initial saving.
Some of the energy-saving bulb's higher upfront cost is unavoidable. This is because it is more complicated and energy-intensive to manufacture a compact fluorescent lamp (CFL), which requires 4 kilowatt-hours (kWh) of electricity to be made, than to manufacture an incandescent bulb, which requires only 1 kWh.
Cheaper prices hide the true cost of traditional bulbs, says Matt Prescott
Unfortunately, the higher purchase price of CFLs has consistently distracted purchasers from the huge running costs associated with using incandescent light bulbs.
This is despite the fact that energy-saving light bulbs need to be replaced less often, consume far less electricity and easily pay back their initial investment, usually within a fraction of their lifetime.
In fact, the German Federal Environment Agency has calculated that, over its 15,000 hour lifetime, a single 20W compact fluorescent light bulb would save 188 euros (£131) worth of electricity.
By comparison, they say that approximately 15 short-lived 100W incandescent light bulbs would be needed to provide equivalent light levels over the same period.
It would clearly make a lot of sense if tightly-regulated labels, highlighted these differences in lifetime and running costs, and enabled consumers to make more informed choices.
It would also make sense if more governments automatically gave their poorest citizens free CFLs, and other energy-saving assistance. After all, guaranteeing significantly reduced energy use, while maintaining levels of light and comfort, would do more than almost anything else to lift people out of fuel poverty.
Beyond the issue of cost, one common consumer concern is that fluorescent lamps contain trace quantities of mercury, whilst incandescent bulbs do not contain any. This would appear to suggest that incandescent bulbs release less mercury into the environment.
On the contrary, the Lighting Industry Federation (LIF) has reported that the extra quantity of mercury emissions from burning fossil fuels in power stations to power incandescent lamps is three times the amount contained in equivalent energy efficient lamps.
Significantly, a CFL has the distinct advantage that its mercury can be collected and recycled, unlike atmospheric pollution. Power stations also produce sulphur and nitrogen oxides which contribute to 'acid rain'.
Specially-designed, but difficult to obtain, energy-saving bulbs can also be used with dimmer switches, and it is my experience that the light quality and warming up times of standard CFLs have improved dramatically in recent years.
Clearly, it would help if manufacturers made more designs of bulb available and retailers ensured that all the energy-saving bulbs they sold worked to a minimum standard and could be disposed of safely.
Sharing the burden
Perversely, the EU's Waste Electrical and Electronic Equipment Directive will soon force CFLs to become more expensive, so that their mercury content can be collected and disposed of safely.
Although responsible CFL collection and disposal are essential, incandescent bulbs will continue to incur no added costs as a result of their atmospheric pollution, and the incentive to buy wasteful technology will be strengthened even further.
In my view, the environmental costs of lighting should be shared by all light bulbs, if well-intentioned laws are not to hinder efforts to save energy.
But what other tax incentives could be used? In the UK, the rate of VAT (sales tax) on condoms has recently been reduced from 17.5% to 5%, in a bid to promote better sexual health.
Why not introduce similar low or zero VAT rates in order to promote energy efficiency?
Every country in Europe now faces a serious problem when it comes to securing new supplies of energy. Wouldn't it be sensible for all EU nations to use their tax and regulatory systems to promote reduced energy demand?
Finally, I would like to address the point that the heat generated by an incandescent light bulb is not wasted completely.
It would also make a lot of sense to stop power stations pumping their surplus heat into the atmosphere via cooling towers
There is a certain amount of logic to this point of view. Especially, as the world's best building regulations result in well-insulated and ventilated homes, which are capable of being kept warm using body heat alone.
However, the UK Market Transformation Programme has shown that using gas heating to replace the heat generated by incandescent light bulbs would reduce greenhouse gas emissions by 60%, and cut the cost of this share of household heating by 84%.
This is partly because electricity is relatively expensive, but also because over 60% of the energy contained in coal and gas is lost simply generating and distributing electricity.
As most UK houses are very poorly insulated, it would be far more cost-effective to insulate houses and to use modern heating systems to provide warmth.
It would also make a lot of sense to stop power stations pumping their surplus heat into the atmosphere via cooling towers. This could be done by using the hot water, left by their steam turbines, to heat local houses and to provide hot water for washing.
Even before this could be done, it would save a lot of money, energy and carbon emissions if we all used light bulbs to provide light, and nothing else.
Dr Matt Prescott is director of banthebulb.org, an online campaign encouraging greater energy-efficiency. He is also organiser of the Oxford Earth Summit, and writes the environmental weblog Earth-Info.net
The Green Room is a series of environmental opinion articles running weekly on the BBC News website