In the Media, Carbon Footprints

Click to view current listings of popular media items for Venditti’s research group. 

The ten things you should know about carbon footprints and global warming potential, simplified.

1.  A carbon footprint is a mass balance of greenhouse gasses (that warm the earth) around the atmosphere. The net amount (additions-removals) of the GHGs that enter the atmosphere provides the carbon footprint.  A process has a net positive carbon footprint if more GHGs are added than removed from to the atmosphere (bad).  A process has a net negative carbon footprint if more GHGs are removed than added to the atmosphere (good).
2. Carbon dioxide CO2 is not the only greenhouse gas.  Many other gasses warm the earth.  Nitrous oxide N2O and methane CH4 are two other critical greenhouse gasses because they are commonly emitted in combustion or decay and they are much more potent in warming the earth than carbondioxide. Fluorinated gasses also contribute to global warming and often have very potent effect on warming.  For instance, N2O and methane are more prevalent than CO2 emissions for agriculture.
3. Carbon dioxide emitted from plant-based materials (biogenic)  is not considered a GHG even though the CO2 does directly warm the earth in the same way as petroleum combustion CO2 (called anthropogenic CO2).  Why?  For example if we burn wood to heat a house, there is CO2 emitted which increases the GHGs in the environment, but these are balanced by the fact that recently the plant took out the same amount of CO2 from the environment as it was growing.  Thus the CO2 net in the atmosphere is zero, ideally.   This can be impacted if combustion is not ideal, for instance if N2O is formed or if methane is formed from plant species due to human processes these must be considered as GHGs that contribute to global warming. Note, that when we burn petroleum, for example, CO2 is emitted but since the petroleum came from crude oil from the ground, and not recently grown plants, there is not counterbalancing effect and the petroleum combustion will have a high carbon footprint.
4. A carbon footprint is measured in units of tonnes of CO2 equivalent / unit product or service.  For instance, a child’s toy might contribute 0.05 metric tonnes of CO2 equivalent per toy.  All of the different greenhouse gasses are expressed as a CO2 equivalent so that the carbon footprint has one unit.  For instance, methane has about 30 times the global warming effect than CO2 so 1 kg of methane is equal to about 30 kg of CO2eq warming.  These factors are updated as new findings occur.
5. We care about carbon footprinting because it is a way to measure and develop improvements that reduce GHGs in the atmosphere.  Scientists have have set goals to avoid earth temperature increases. The most mentioned goal is to avoid a greater than 1.5 C increase in earth temperature by 2050.  Comparisons of carbon footprints allow us to design and choose products and services that have lower earth warming contributions.
6. Global warming is a very complex process and GHGs are not the only factor.  In fact GHGs caused by human activity is about 14.7 billion tonnes of CO2eq per year.  This is dwarfed by other GHG flows from plant growth, plant decomposition/weathering, and ocean/atmosphere interactions, whose flows can be in the 100’s of billion tons of CO2eq per year. Further, non GHG events impact the temperature of the earth, including cloud cover, contrails from airplances, solar flares, and changing amounts of snow or land use changes.
7. You can get paid for reducing your GHGs (carbon footprint).  There are voluntary markets in which you can offer your carbon footprint reductions and get money for it. These markets ar called the carbon market, and the unit of the market is in saved metric tonnes of CO2eq.   Programs soley intended to take CO2 out of the atmosphere also can get paid for carbon savings.  Other companies buy these carbon offsets and there company can be more carbon neutral. The price is about $25/metric tonne.
8. There is alot of opportunity for fraud in the carbon market.  If an entity wrongfully claims carbon footprint reductions or exagerates their reductions fraud is committed.  Estimates vary about how much fraud is happening but these estimates are a significant amount of the total carbon that is traded. Additionality is the term used that credible carbon savings are determined.  Additionally, many critics of carbon markets suggest that by making carbon offsets available that it gives license for purchasers to extend their poor carbon footprint processes, promoting more global warming.
9. In the future, all products and services might have carbon footprinting labels similar to nutrition labels on food now.  Currently there are many environmental declaration labels on products but consumers need to be aware that they are not all consistent in their enviromental measuring and reporting and that greenwashing can sometime occur.
10. Carbon footprint is only one component out of many environnmental indicators for a product or service.  Only looking at a carbon footprint can be very misleading.  For instance, a product may have a low or zero carbon footprint but also may have environmentally damaging other impacts, for instance, acidification, eutrophication, emission of carcinogens, wildlife habitat destruction, water pollution, resource depletion, etc,.   There are often tradeoffs between carbon footprints and these other environmental impacts, do not blindly evaluate a product or service by carbon footprints alone.   It is frustrating to compare one product to another since there are so many environmental indicators and different people value different environmental indicators differently.