The previous week, part TWO of this post was on the benefits which digital, web-based prototyping will make exportation and presentation easier. This FINAL part will show you how iterations can be made easy and that using digital solutions will in fact help against the fight of global warming.
Quick Iteration: 
One of the main benefits of using the digital solution is the possibility to make us of quicker, easier and cost-effective iterations. But this will only happen if the prototype can be adjusted to new requirements in an instant. Digital paper prototypes can be re-used and won’t have to be created all over again once a new iteration starts. You simply have to adjust specific elements once and then apply those changes to the rest of the prototype, that’s it.
Sustainability: 
The average usability testing project leaves a footprint of approximately 250 kilograms, or 0.25 a tonne of CO2. That may not seem much but that is close to amount of CO2 emission as a 3 hour flight. Usability testing is universally seen as the best way to improve a system’s ease and satisfaction of use. If one usability test itself emits the equivalent of a 3 hour flight, there clearly are considerable gains to be made! In an ordinary usability test, someone travels from his/her location to a laboratory or office where they interact with a test facilitator. Normally this takes about an hour and the process is repeated with 7 to 10 people.
The carbon emission for a usability testing project is based on an average of 10 participants, with each participant traveling 20 kilometers return to get to the test and spending 1 hour with the test facilitator.
More on: http://www.prnewswire.com
Conclusion:
By making use of the newest technologies it is now possible to make the shift from paper-based prototyping to digital or web-based prototyping. User-centered design, sharing of ideas, iterative work-flow, collection of feedback and collaborative work are all aspects which speak in favor of implementing such process. Developers, designers, clients and test-users alike can benefit from working on digital prototypes which engage them from the very first idea. Unnecessary iterations which often confuse and hinder continuous work-flow can be a thing of the past since everyone will be up-to-date. Test-users can work in their natural surrounding whilst the design team can make changes on-the-fly.
Overall, web-based prototyping can only be beneficial for all parties involved. Also, since using excessive sheets of paper can be a thing of the past, it will be a make our planet a little greener.