Technological Opportunities for Emissions Reductions

As evidence of rapid climate change grows worldwide, so does the need for action. Though governments and others are locked in debate over what should be done - and who should do it - many measures to cut greenhouse gas emissions can be taken today. Households, organizations and others need not wait for governments to lead the way before stepping forward on their own.

The most sensible early initiatives are those that are already justified for other reasons, where benefits exceed costs independent of any climate considerations. Among the best candidates is a wide array of commercially available energy-related technologies. Some produce useful energy, like electricity, while emitting fewer greenhouse gases. For example, photovoltaic panels convert sunlight directly into electricity while emitting no greenhouse gases.

Other technologies provide useful services such as air-conditioning or light while using energy more efficiently. Since most energy is provided by high-carbon fuels that release substantial amounts of greenhouse gases, then higher efficiencies result in lower emissions given the same level of usage. For example, energy efficient air-conditioners can substantially reduce carbon emissions by reducing electricity demand from power plants burning fossil fuels. There are additional near-term benefits that alone justify investing in the air conditioners: they can reduce the frequency and severity of power outages (by reducing peak demand for electricity), reduce emissions of other pollutants, and lower electricity bills.

Throughout this site, we refer to emissions savings as a result of improved energy efficiency. Note that this relationship between efficiency and reduced emissions assumes that the energy-efficient product provides the same level of service as the original product. In the air-conditioner example above, if a new air-conditioner is said to reduce emissions by 20%, this assumes that the new air-conditioner provides the same level of service (cooling) while using 20% less energy, and also that the new air-conditioner is used in the same way as the old one. To demonstrate an example where the relationship would not be accurate: it would not be accurate to say a 75-watt bulb is 25% more efficient than a 100-watt bulb, because the 75-watt bulb is not providing the same level of service. Throughout this site we equate gains in energy efficiency with reduced emissions, without constantly re-stating the assumption of equivalent level of service provided and equivalent usage. We also assume that the user is not taking savings from one area and using that energy elsewhere, for example by purchasing an energy efficient car but then driving more miles.

Cut Emissions with Better Lighting

Lights provide another illuminating example of the potential for individuals to reduce greenhouse gas emissions while enjoying other valuable benefits. According to the US Department of Energy (DOE), lighting accounts for roughly a quarter of US electricity demand, at a cost of more than $37 billion annually. The Rocky Mountain Institute (RMI) estimates that about 80% of the electricity usage claimed by lighting is used to power the lights, with the remainder electricity being required by air conditioners to remove the waste-heat generated by those lights. So more efficient lighting not only reduces direct energy use by lights, but also cuts the energy demand for air conditioning.

Given the potential for reducing emissions, it is not surprising that one of the major elements of the 1993 US Climate Change Action Plan was expanding the Environmental Protection Agency's Green Lights initiative, hoping to reduce greenhouse gas emissions by 2.5 million metric tons of carbon-equivalent between 1990 and 2000.

One of the leading technologies for reducing the demand of energy for lighting is the highly efficient compact fluorescent lamp (CFL). Recent advances in CFL technologies mean that high quality CFLs are now indistinguishable from the incandescent bulbs they replace both in terms of light color & quality and functionality. DOE says CFLs "are the most significant lighting advance developed for homes in recent years," and that their "energy savings and superior longevity make CFLs one of the best energy efficient investments available."

CFLs last 10 to 15 times longer and use 75% less electricity to deliver the same level of light compared to the typical incandescent bulb which they replace. Each CFL replacing a regular bulb prevents emissions of 1,000 to 2,000 pounds of greenhouse gases (CO2) and 8 to 16 pounds of polluting sulfur dioxide from power plants, as well as eliminating the need to produce, and ultimately discard, up to a dozen incandescent bulbs. CFLs cost less than $10 and will net the buyer between $30 and $70 in savings over its lifetime on electricity bills and replacement bulbs, providing a better return on investment than the average stock market portfolio. As Rocky Mountain Institute's head says "This isn't a free lunch, it's a lunch you're paid to eat!" And the potential is huge. There are nearly 3 billion light sockets in the U.S., half of which are candidates for CFL replacement. CFLs are available from local hardware and home-improvement stores or through SafeClimate.

Technology, Economy, and Greenhouse Gas Emissions

From CFLs to energy-efficient automobiles, greener technologies are being developed and promoted not only by manufacturers, but also by many others ranging from the US Environmental Protection Agency's Energy Star program to the American Council for an Energy Efficient Economy (see Additional Information below.)

Can individual technology and energy choices like changing your lights really make a dent in national or even global emissions? They certainly can when a lot of people make similar choices - even when those choices are not primarily made to reduce greenhouse gas emissions. Take the record of the last several decades. The "energy intensity" of the US economy (energy used per dollar of Gross Domestic Product) has fallen substantially (see our article, Divergent Paths), with the pace quickening as the "Internet economy" develops. The Internet Economy and Global Warming, published in 1999 by the Center for Energy and Climate Solutions, says the US economy grew 4% annually in 1997 and 1998 while energy consumption increased only 1% annually. The economy's energy intensity therefore declined at an annual rate of 3%. In 1998, US carbon emissions increased only 0.2%.

The report attributes the most recent decline to the Internet economy that is generating both structural changes and efficiency improvements in all sectors. While noting "it is certainly not possible to draw more than tentative conclusions at this point," they expect US energy intensity to continue to decline at least through 2007.

Resulting partially from technological changes such as growth of the Internet, trends in economic and emissions growth have diverged. The "carbon intensity" of the economy has fallen spontaneously even without a major coordinated effort to develop and deploy new technologies to reduce greenhouse gas emissions. However, with such an effort from individuals and organizations, emissions can be cut much further without hurting the economy.

The potential is confirmed by a major US Government study issued in 1997. According to Scenarios of US Carbon Reductions; Potential Impacts of Energy Technologies by 2010 and Beyond, (see our article Labs Describe Technological Push to Curb Emissions), technologies that are energy efficient or use relatively low-carbon energy sources could help avoid a projected 30% increase in US emissions between 1990 and 2010. In all of the scenarios considered in the government study, the costs of implementing policies were less than the resultant energy savings. And, the laboratories conclude, "a next generation of energy-efficient and low-carbon technologies promises to enable the continuation of an aggressive pace of carbon reductions over the next quarter century."

Additional Information

Houses & Household appliances

-Consumer Guide to Home Energy Savings: 7th Ed. Book from the American Council for an Energy Efficient Economy. Highlights are available online along with list of top-rated energy-efficient appliances

-From the Rocky Mountain Institute:
-Homemade Money: How to Save Energy and Dollars in Your Home
-Home Energy Briefs.
-Home Energy magazine.

-The Smart Kitchen. "How to Design a Comfortable, Safe, Energy Efficient, and Environmentally-Friendly Workspace."

-No Regrets Remodeling. "Creating a Comfortable Healthy Home that Saves Energy."

-How to Build a Better Home (PDF 587 KB). Brochure (June 2000) from the National Renewable Energy laboratory.

Commercial Buildings & Offices

-Guide to Energy-Efficient Office Equipment: 2nd Ed.
From the American Council for an Energy Efficient Economy

-US Green Building Council. "The building industry's only balanced nonprofit consensus coalition promoting the understanding, development, and accelerated implementation of `Green Building' policies, programs, technologies, standards, and design practices."

-Rocky Mountain Institute, Library: Business


US Department of Energy, Energy Efficiency and Renewable Energy Network:
-Buildings: Lighting.
-Consumer Information: Lighting & Daylighting
-International Association of Energy-Efficient Lighting

-Lighting Research Center. Located at Rensselaer Polytechnic Institute (Troy, New York)

-Rocky Mountain Institute: Home Energy Brief #1, Lighting (1994) (PDF-366k)

Transportation The online home of the American Council for an Energy Efficient Economy’s (ACEEE) Greenbook : The Environmental Guide to Cars and Trucks. Includes list of links.

-Clean Car Campaign. - U.S. government's official fuel economy website.

-US Department of Energy, Office of Transportation:
-Consumer Tips.
-Clean Cities
-Alternative Fuels Data Center
-Fleet Information and Regulations
-Available Vehicles and Refueling Sites
-Related Links
-US Environmental Protection Agency, Office of Mobile Sources. Wide range of material on transportation issues. For general information, the Consumer Information and General Interest section is most useful, as it includes many links to readable and informative documents (including many in Portable Document Format or PDF). See also section on Fuel Economy that includes the Fuel Economy Guide for the latest vehicle model year.


-American Council for an Energy Efficient Economy. Includes list of other sites concerning energy efficiency.

-Rocky Mountain Institute.

-US Department of Energy
-Energy Efficiency and Renewable Energy Network. The Office of Energy Efficiency and Renewable Energy (EE) says its mission is "to lead the Nation to a stronger economy, a cleaner environment and a more secure future through development and deployment of sustainable energy technologies." EE characterizes the Energy Efficiency & Renewable Energy Network (EREN) site as the "premier resource for information on the Internet about renewable energy and energy efficiency technologies." The site provides information on EE offices and program, including DOE's Energy Partnership Guide. The guide supplies details on the agency's partnerships with others in all sectors to realize lower greenhouse gas emissions along with other goals. The partnerships include the Best Practices team (formerly Motor Challenge Program) which promotes energy-efficient electric-motors.
-National Renewable Energy Laboratory, Clean Energy Basics
-US Environmental Protection Agency:
-Global Warming > Actions
-Climate Protection Partnerships Division (CPPD). Includes links to Energy Star Programs and Products.  
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