In 1994, chemistry professor Martin B. Hocking conducted a study that focused on a life cycle assessment of different kinds of reusable and disposable cups in terms of their energy usage and consumption. The results of the study challenged what was then conventional wisdom about some of these products. Dr. Hocking documented the amount of energy required to produce and reuse cups made from various materials. The conclusions were somewhat shocking - the study concluded that in some cases, using paper and polystyrene cups is actually more energy efficient than other alternatives. For example, when the amount of energy consumed during the production of a ceramic cup is weighed against the energy required to produce plastic cups, the ceramic cup must be used 1,006 times before the user "breaks even" (versus using 1,006 plastic cups). However, this number does not account for the energy consumed to wash the cup. When that energy is considered, the ceramic cup never "breaks even" with the polystyrene cup because it often takes more energy to wash a ceramic cup than it does to produce one polystyrene cup. The same study compared numerous cups and materials and the "break even" point between reusables and disposables was much smaller for some other materials. For example, when comparing glass mugs to paper cups, the "break even" point for the glass mugs was only 15 uses. In any case, the study was successful in that it prompted people to consider the factors that are in play when they opt for "reusable" alternatives. The simple fact is that some things aren't as eco-friendly as you might think...at least when it comes to energy consumption.

But, energy consumption is not all this is involved in the analysis when you compare disposable versus reusable bags, cups, and any other disposable versus reusable product. Things like disposal, recyclability, toxic chemicals that the factories release during production, and other environmental factors must also be considered. Polystyrene may consume less energy in it's production, but it isn't biodegradable or recyclable and takes centuries to degrade in landfills, leading to overfilling of landfills. Paper cups can be recycled and are more biodegradable, but the factories that produce paper cups and other paper products are some of the biggest polluters in the world. Further, paper cups require a great amount of water to produce and obviously require the deforestation of millions of acres of trees. Plastic cups are petroleum based (like all plastic products). Petroleum is a finite resource but is also something that is toxic to soil, air, water, and wildlife when it is disposed of improperly, extracted, refined, and/or spilled.

Of course, every product (reusable or disposable) has an impact on the environment in some way or shape. This makes it difficult to find the optimal solution in every case. Although things like reusable bags, reusable containers, and reusable cups seem like better alternatives than their disposable counterparts, it is important that consumers are informed when making those decisions. For example, reusable shopping bags made from organic cotton are more environmentally friendly than bags made from non-organic cotton and bags made from recycled materials are generally more eco-friendly than either organic or non-organic cotton. When it comes to cups, stainless steel mugs are less eco-friendly than ceramic cups even though stainless steel mugs are made largely from recycled materials because the greenhouse gas emissions associated with producing mugs from stainless steel. If you're ever in doubt about what is the best alternative, you can generally opt for recycled goods and know that you're having a positive impact on our environment.