First, what are greenhouse gases? I went to the National Oceanic and Atmospheric Administration National Climate Data Center for the answer (www.ncdc.noaa.gov/oa/climate/gases.html). A variety of chemical compounds present in the earth's atmosphere behave as greenhouse gases. These gases allow direct sunlight to reach the earth's surface unimpeded. As the energy in that sunlight heats the surface, infrared energy is re-radiated to the atmosphere. Greenhouse gases absorb this energy, allowing less heat to escape back to space and keeping it here, in the lower atmosphere.
Many greenhouse gases occur naturally in the atmosphere, such as carbon dioxide, methane, water vapor, and nitrous oxide. Others are synthetic – manmade – and include chlorofluorocarbons (CFCs), hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), and sulfur hexafluoride (SFL).
Here's the problem: Both natural and synthetic gases have been rising over the last 200 years because of industrialization. Along with a growing global population and our use of fossil fuels such as coal, oil, and natural gas, emissions from natural and synthetic gases have increased. Our natural system is unable to process the larger emissions. We end up moving more carbon from solid storage to its gaseous state, thereby increasing atmospheric concentrations of both, i.e., a rise in greenhouse gas.
Water vapor is the largest greenhouse gas in the atmosphere. While we don't completely understand the entire cycle of water vapor, we do know that changes in water vapor concentrations affect climate change. According to the National Climate Data Center, "As the temperature of the atmosphere rises, more water is evaporated from rivers and oceans, etc. Because the air is warmer, the absolute humidity can be higher, leading to more water vapor in the atmosphere. As a greenhouse, gas the higher concentration of water vapor is then able to absorb more thermal IR energy radiated from the earth, thus further warming the atmosphere."
Carbon dioxide (CO2) is also a greenhouse gas. The natural production and absorption of CO2 has been disturbed by changes brought on by us, mankind. We are burning the aforementioned fossil fuels in larger and larger volumes. The natural cycle cannot dissipate the increased amount of CO2.
Methane is another greenhouse gas. It, too, is generated by a natural process similar to that of swamplands or rice production. Over the last 100 years, human activities such as farming, mining and the use of natural gas have added increased concentrations of methane. Landfills generate methane, and it is only recently that we see waste management companies capturing this landfill byproduct and converting it to energy. There's a similar story in converting the byproduct generated in cattle feed lots into energy. Suffice it to say we don't capture enough methane and the higher concentrations cause additional greenhouse gas.
The family of chlorofluorocarbons mentioned in the beginning, along with VOCs (volatile organic compounds such as non-methane hydrocarbons and oxygenated non-methane hydrocarbons like alcohol and organic acids) are also considered greenhouse gases.
Sadly, people have caused the problem, not nature. In balance, greenhouse gases are "controlled" substances. Out of balance, they cause climate change, which, certainly in the last several years, has resulted in cataclysmic weather changes, which has cost the world billions and billions of dollars.
Along with understanding greenhouse gas is a definite confusion over terms like "bio-based" and "biodegradable." These terms are used in reference to types of packaging. A study run by the Biodegradable Products Institute found that 85 percent of consumers thought that bio-based/renewable also means biodegradable, and 60 percent thought biodegradable products magically disappear when thrown away. I think much of the blame must go back to the messages on labels. They focus on product features, not consumer benefits. The message isn't clear.
Biodegradability, according to the Society of Plastics Industry (SPI), means that a package undergoes a breakdown of organic material in the presence of microorganisms (bacteria, fungi, algae), usually in a heat- and moisture-controlled environment. Biodegradation is not thermal, UV, or hydro degradation.
Bio-based content is the fraction of the carbon content that is "new" carbon content, made up of biological materials or agricultural resources versus fossil carbon (old carbon). There is an ASTM standard for measuring bio-based content.
If we then press forward and talk about bioplastics, we can go back to SPI, which defines bioplastic as "a plastic that is biodegradable, has bio-based content, or both." Are you confused? Jeff Timm, an authority on bioplastics and the principal of Timm Consulting, recommends several organizations for further clarification. Over the years I have mentioned the same groups: The Sustainable Packaging Coalition (SPC), GreenBlue, Federal Trade Commission (FTC), Consumer Goods Forum (CGF; known in Europe as CFF), and Global Packaging Project (GPP), also in Europe and really the predecessor of CGF.
Timm maintains that there are many more offerings of bioplastics that fall into bio-based rather than biodegradable. Hence, my interest in trying to clarify the terms and the use of the same. He goes on to say that when bioplastics were first introduced they were almost exclusively biodegradable polymers derived from renewable resources like corn. (Remember PLA and the next generation, PHA). Timm believes that the easiest way to look at bioplastic is to separate creation versus end of life. "The confusion develops when we combine the creation and disposal in the same definition� Biodegradation and recycling are both end-of-life outcomes. Words like biosources, bio-based, and renewable are from the creation side."
The argument, I think, is really which is more important, creation or end of life (shades of Darwin, don't you think?). Timm doesn't deal with this. If we create materials that are not compatible with recycling, I think there's an issue. The recent activity in Canada regarding pressure sensitive labels on PET thermoform containers is a great example.
The Canadian government is charging a "stewardship tax" for packaging that is not recyclable. Pressure sensitive adhesive labels that are used on PET thermoformed containers render the PET product non-recyclable. PET is recyclable but with that PSA label it becomes non-recyclable. In my view it puts this label application at risk.
So we have created a wonderful product without any concern for end of life. I fault the OEMs and adhesive manufacturers from start to finish on this. We are not addressing the entire cycle. A manmade product has upset normal cycles. The solution, in my view, is available if industry will be proactive. We have the skill to take product technology and create an adhesive that is compatible with PET thermoform recycling. Shame on us, all of us in the supply chain, for not addressing both creation and end of life.
That's the whole issue with greenhouse gases. Once we upset the natural cycle, we put environmental stress on the system, in this case the atmosphere. We have the capability to make change. It's culture that prevents us from performing. That's how I see it from here.
Another Letter from the Earth.
Calvin Frost is chairman of Channeled Resources Group, headquartered in Chicago, the parent company of Maratech International and GMC Coating. His email address is firstname.lastname@example.org.