Sustainability encompasses so many things: from science, technology and nature down to small things such as recycling, reusable water bottles and turning off lights in empty rooms. The push for sustainability is a call to re-learn how to live within our means on this planet–something we have forgotten. But I see the most important aspect of sustainability in the photo above: teaching the future leaders of the world to be accountable for our environment so that our progress in sustainability efforts can be sustained in the decades to come.
A quick “define: sustainable” search in Google turns up this response: able to be upheld or defended. Our efforts to live green cannot be upheld if we do not teach the future generations how to do so. Earth cannot be defended if our society, particularly youth, is not educated. And so I believe the most important definition of sustainability is this: to educate the public on living green and living within the limits of Mother Nature.