A head-to-head comparison of print versus digital signs tips the environmental impact scale in favor of the digital medium.

For more than two months when I've gone home from work and flipped on the evening news, hoping to see the volcano of oil erupting one mile beneath the Gulf of Mexico miraculously stilled, plugged somehow, staunching the incredible flow of oil and natural gas that is killing wildlife, devastating habitat and shutting down whole segments of Gulf-related businesses.

But rather than breathing a sigh of relief, night after night I'd sit mesmerized - a little queasy and apprehensive - watching the oil continuing to flow, creating what seems to be the greatest environmental calamity in my lifetime - at least in this part of the world.

Like everyone else at home marveling at this spectacle revealed by BP's underwater camera, I am powerless to do anything to "just plug the damn hole," as our president reportedly said at a recent White House meeting. Fortunately, BP's latest attempt to cap the wellhead appears to be working, and there may be some end to this phase of the environmental disaster in sight.

But regardless of what happens a mile below the sea, it's important to recognize that I'm not powerless in my personal and professional life when it comes to helping to protect the environment. That's why, along with my decision to drive a fuel-efficient vehicle, recycle paper, glass and plastic and teach my children to respect the environment in their daily lives, I've decided to dedicate a couple of columns to digital signage as a "green" technology.

Often, when the environmental impact of digital signage is raised, some valid but rather well-worn, assertions are made. First, when compared to printed signs, digital signage appears far greener. Digital signage messaging, which can be updated or changed entirely with a few strokes of the keyboard and some mouse clicks, eliminates the need to print new signs as messaging needs change. The fewer signs that get printed, the fewer the trees that need to be cut, transported to mills, processed and made into paper, the logic goes. The need for the inks used to print the signs and the various chemical coatings applied to make them attractive is eliminated.

Another dimension commonly cited is waste disposal. Cutting out the need to replace printed signs eliminates the energy needed to dispose of or recycle the signs and - to the degree printed signs aren't recycled - the impact of adding tons more paper, ink, chemical coatings and paints to landfills.

A third often-cited benefit is that the convenience of updating digital signage messaging over a computer network eliminates travel to the location of each sign, which is necessary to replace printed old signs with new printed versions. Eliminating the transportation component reduces carbon emissions and thus the impact of signage on the environment.

While each of these assertions argues in favor of the environmental benefit of using digital signage over traditional printed signs, that's not to say digital signs don't impact the environment and that a variety of actions can and should be taken when possible to reduce the effect of this digital medium on our planet.

In the second part of this column, I'll look at some of the leading environmental considerations regarding the use of digital signs and steps that can be taken to minimize their impact.

The rapid adoption of touchscreens in multiple consumer devices demands attention in the digital signage realm.

If adding interactivity to your digital signage communications mix hasn't been top-of-mind, it's time to re-evaluate and give serious consideration to tackling touchscreen technology.

To be sure, not all digital signage uses call for interactivity, but many signs employed today for simple wayfinding, retail promotion and other applications can leverage touchscreen interactivity to better serve the informational needs of viewers, and in so doing, deliver a communications experience more in line with the goals of the enterprise.

Reconsidering the role of interactivity in digital signage messaging has taken on added urgency recently as consumers buy and fall in love with touchscreen gadgets like the Apple iPad and even touchscreen PCs.

Consider the latest statistics on touchscreens from market research organization iSuppli. Shipments of touchscreens for devices like Apple's iPad are expected to rise nearly 5,000 percent to 8.9 million this year, according to an iSuppli forecast. That's up from 176,000 in 2009. By 2013, the research company projects shipments to increase sevenfold to 63.9 million units.

The popularity of touchscreen interactivity isn't restricted to iPads and iPad competitors in the pipeline. According to iSuppli, the personal computer touchscreen market is expected to grow by 242 percent this year.

As consumers by the millions adopt PCs and tablet-type computers with touchscreens, their expectations about technology are likely to evolve. Whereas at one time no one would give second thought to a wayfinding digital sign, other than to absorbing the directions being conveyed, it's entirely likely wayfinding viewers of the near future will wonder why they can't touch the screen, call up a more detailed map and touch highlights along their route to learn more about them.

The number of consumers looking for greater interactivity with retail digital signs also is likely to climb as the number of touch-screen tablet device owners grows. With touch screen interactivity becoming a growing habit, why wouldn't shoppers expect to do something as iPad-like as dragging a digital sweater from one interactive shelf and a pair of slacks from another onto a virtual mannequin to see whether they match?

Taking this type of interactivity to the next level, why shouldn't traditional digital signage offer touchscreen interactivity via the very tablet computers, like the iPad, that are driving the explosive growth in the touchscreen market? After all, iPads come with either 3G and/or WiFi connectivity built in. Giving an iPad permission to take temporary control of a digital sign in a retail store would let customers benefit from the interface they know and love on their tablets and the 42- or 50-inch display that delivers larger, more impactful images that better emulate the real world.

Digital signage communicators who ignore the forecast of explosive growth in touchscreen enabled devices do so at their own peril. To be sure, not all digital signage applications are appropriate for interactivity, but the ubiquitous presence of consumer devices controlled via touchscreens demands a serious re-evaluation of digital signage communications strategies.

Now is the time to begin that re-examination, because it may be too late to make a strategic shift once 64 million touchscreen devices are in the hands of consumers worldwide. Launching a review today will let digital signage communicators proactively plan to take advantage of this tidal wave in touchscreen familiarity rather than flat-footedly responding to this likely sea change in consumer expectations.