Lets face it: climate change has gone mainstream. It’s cited as the explanation for virtually every odd weather event which has taken place in the last year. Hurricane Katrina left the US, and probably most of the globe, stunned by the ferocity of the storm and the incredible damage it caused to a country and city which seemed unprepared, because this kind of event had not happened in the 400 years that people lived in the area.
Naysayers will say the weather is a random event, statistically to be expected. Others feel it may presage things to come. An explanation was needed for how a medium level storm changed into a hurricane that put people in five states out of their homes and caught the richest country in the world unprepared. The general answer was that Mother Nature is larger than all of us, and she’s in a bad mood because she’s got a temperature. Specifically, the Gulf waters were warmer than normal, which intensified the evaporation that fed the storm.
Tim Flannery’s book The Weather Makers explains the science, and if you don’t want to plough through 300 pages of scientific explanations, the Al Gore film An Inconvenient Truth explains it all with very good graphics. For Canadians, the thought of polar bears becoming extinct speaks to the core of what it means to be Canadian; it’s having the same impact as the ad about the 63 year old Swede being fitter than a young Canadian (which was a call to arms to exercise 30 years ago). A friend went to Churchill, Manitoba last fall to see the polar bears and was dismayed to hear there were only 900 this year compared to 1200 last year. People in Churchill are seriously concerned there may come a time when no polar bears left in their area.
At the Globe conference in March 2006, a speaker from the north described various adaptation techniques they have used because everything is warmer and mushier; trucks get lost on ice roads that are not rock-hard anymore (one trick is to paint the trucks a non-white color, so they can be found in the snow!).
Even Guy Crittenden, the editor of this magazine and a global warming skeptic, has written about his concerns that man-made climate change may indeed be real and that a precautionary approach is warranted. Whatever your views may be, policymakers are taking the issue seriously and the waste management industry has to ask itself what it can do to help reduce greenhouse gas emissions.
As it turns out, we can do quite a lot, and we can have a real impact.
Waste management’s contribution
By now, most people know that climate change and global warming are currently thought to be linked to CO2 concentrations in the atmosphere. The concentration of this gas has been increasing since the Industrial Revolution because we’re liberating vast amounts of carbon which have been stored in the ground over millennia through burning of coal, oil, diesel and natural gas for energy generation. (CO2 acts as a “blanket” keeping us at a comfortable temperature. Increasing the CO2 concentration is like throwing an extra blanket on your bed; more heat gets trapped and you get hotter.) There are six main greenhouse gases (GHGs): for waste managers, the two greenhouse gases we deal with most are CO2 and methane (CH4) which is 21 times more powerful than CO2 in terms of global warming potential.
According to the Canadian government’s 1997 Second National Report on Climate Change, waste management activities (mostly landfill related) are estimated to contribute 3 per cent (18 million tonnes) of Canada’s annual greenhouse gas emission total of 610 million tonnes of eCO2 (equivalent CO2) per year.
There are various ways to estimate the GHG impacts of waste management decisions, but regardless of the approach used, the bottom line is that recycling is good for climate change, because manufacturing with recycled products uses a lot less energy than manufacturing with virgin products, and the use of energy created by burning coal, natural gas or oil causes greenhouse gas emissions. The GHG emissions from all collection trucks plus transportation of recyclables to manufacturing are taken into account to come to this conclusion.
Landfills create methane from the breakdown of organic material in an anaerobic environment. In the old days, methane simply leaked into the ground or was collected and flared. Nowadays methane is often collected and burned in engines at landfills to create power. (See last magazine edition.) This has two climate change benefits:
* The methane is not released to the environment, where it is harmful, and
* It creates power and “offsets” the demand for oil, natural gas or electricity from other sources.
It’s worth noting that anaerobic digesters do the same thing in a very controlled environment, and more quickly than in a landfill, which is why interest in that technology will increase with time.
The GHG impacts of the collection trucks which collect material for recycling, garbage and organics are actually small compared to the huge GHG benefits of recycling materials such as aluminum, steel, paper and plastic (referred to as the “upstream benefits” in lifecycle language)
It takes less energy to make material from recycled rather than virgin stock. (See table.) The table shows that the biggest winner is aluminum, where making a tonne of aluminum from recycled aluminum requires only four per cent of the energy required to manufacture aluminum from virgin material. The energy calculations include the raw material extraction (bauxite) at the mine, as well as smelting to create aluminum.
The calculations for paper include the fact that you don’t need to cut down as many trees in the forest if you can create paper from recycled stock.
Thermal processing is usually seen as good for climate change because it creates energy which offsets the need to burn coal, oil or natural gas.
Composting is good for GHG reduction, as it keeps organic materials out of landfills, where they generate methane (a bad actor in climate change). The net carbon calculations for composting are small, as most of the impacts are considered “biogenic”, meaning they would have happened anyway
The perception is that collection trucks use huge amounts of carbon based fuel, as they run on diesel. This is true, but the GHG impacts of collection of recyclables and organics (at the local level) are small compared to the lifecycle GHG benefits of using recycled rather than virgin stock.
Three calculation models
Waste management practitioners can use three different models to estimate the GHG impacts of their decisions.
The Integrated Waste Management (IWM) Model: The IWM Model is the most comprehensive of the GHG impact modeling approaches available to Canadian municipalities at this time, in that it estimates the broad environmental impacts of waste management decisions, including GHG, smog precursors, acid gases and wastewater impacts. The goal of the IWM model is “to give municipalities a broad indication of the environmental effects and economic implications of waste management decisions, and to point to strategies that can improve the environmental performance of their waste management systems” The model is available free of charge to any municipality wishing to use it at http://www.iwm-model.uwaterloo.ca/
The Federation of Canadian Municipalities (FCM) Partners for Climate Protection (PCP) Model: Municipalities across Canada that are part of the FCM PCP program use a PCP model to estimate GHG effects of all corporate and community activities and actions. The PCP model deals with waste somewhat differently from the other two approaches, in that the impacts of the trucks collecting garbage, organics and recyclables are included in the fleet section of the model. The impacts of recycling and composting are measured by the tonnes
of material diverted from the landfill, and therefore, result in lower GHG emissions from the landfill.
For details, see http://www.fcm.ca/scep/support/PCP/pcp_tools_resources.htm
The ICF Consulting Model (Environment Canada and Natural Resources Canada): ICF Consulting has developed a model which adapts the USEPA GHG estimation methodology values to address Canadian energy conditions. Emission factors by material can be used to compare the GHG impacts of recycling, composting, anaerobic digestion and thermal treatment of selected materials in the waste stream with the impacts of landfilling. The most recent version of the model and the supporting documentation was released in October, 2005.
We need to transform the energy technologies we use, and reduce our use of carbon based fuels. We have proven we can do this numerous times, and each time we change the energy source we use, the economy improves. When we moved from steam engines to electricity, the economy grew. When Winston Churchill was Lord of the Admiralty, he made what was considered a very risky decision to move the fleet from coal to oil. Oil was a new technology which had many advantages: easier to refuel, less weight, etc. However, it took courage and determination to make the decision, and to some extent a giant leap of faith. We need to do the same now and move away from petroleum based energy systems to newer, more efficient energy sources. The economy will be more efficient as the world is slowly realizing, and waste management professionals have a role to play.
Maria Kelleher, M.Eng., P.Eng., is principal of Kelleher Environmental in Toronto, Ontario. Contact Maria at firstname.lastname@example.org
Landfill gas utilization in Canada
There are many different uses for recovered landfill gas including electricity generation and direct fuel use for heating and manufacturing purposes. Here are a few examples of how landfill gas is used across Canada:
* Optigaz, Montreal, QE — electricity generation;
* Saint Michel, Montreal, Quebec — electricity generation;
* Cambridge Landfill, Cambridge, Ontario — fuel used in steel production;
* Waterloo Landfill, Waterloo, Ontario — electricity generation;
* Clover Bar Landfill, Edmonton, Alberta — electricity generation;
* Jackman Landfill, Langley, British Columbia — fuel used to heat greenhouse; and
* Port Mann Landfill, Surrey, British Columbia — fuel used in wallboard manufacturing.
Source: Environment Canada, Landfill Gas Bulletins atwww.ec.gc.ca/nopp/lfg
IWM and the City of Calgary
The City of Calgary used the IWM model to evaluate potential changes to its waste management system. When compared with its base case (zero landfill diversion) scenario, the following proposed activities resulted in reduced GHG emissions and energy consumption:
* 50 per cent increase in city recycling;
* 50 per cent increase in composting;
* landfill gas and energy recovery;
* combined landfill gas and energy recovery and increased diversion.
One of the most effective methods to reduce GHG emissions used landfill gas and methane recovery for energy products. In fact it was determined that this activity alone could reduce GHG emissions equivalent to taking 70,000 cars off the road in one year
Landfill gas recovery at the Port Mann Landfill
Landfill gas is collected from Port Mann Landfill near the City of Surrey, British Columbia, which has been closed since 1997. Since 1993, Georgia-Pacific (formally Domtar) has used the gas as a direct fuel in the manufacturing of wallboard.
The gas is pre-treated before being sent by a 6 km pipeline to the Georgia-Pacific plant at which point it is blended with natural gas to produce a fuel that is used to provide heat to the drying kiln and calciners in manufacturing wallboard.
Click here to view the tables from this story.
Source: Environment Canada, Landfill Gas Technical Bulletin atwww.ec.gc.ca/nopp/lfg