According the Triple Helix model, academies or universities shape one of the three acting spheres in a knowledge society. The other two are industries and governments. We should consider the whole world as a single but compound society when addressing sustainability as all parts of the world are interconnected.

On the other hand none of the 3 bottom lines of sustainability can represent it alone.

Various types of LCA are only a group of techniques that enhance the process of design and decision making by clarifying consequences of various alternatives. Again, they are processes and not goals.

(Arguably) The last updated sustainable development goals (17 SDGs) defined and published by the UN should be taken into account while analyzing anything related to sustainability.

Up to here, we see how complex it would be if we consider all the role players of sustainability in a global scale.

In summary, replying to your question, I would say sustainability isn't just a buzzword in academy. Many researchers have worked hard to define and address it. However, it is extremely complex in reality and there's still long way to go to hopefully realize it someday.

Sustainability is a rather old concept and has been used in forestry for more than 300 years. In short, it means that you should not cut more trees than grow at the same time, or you will not have any forest at some point.

So, sustainability is not a funky buzzword but a rather practical action advice.

To substantiate Benni's answer I am attaching a journal article I wrote years ago that may be of assistance to define sustainability and also delineate its physical boundaries.

You've got 3 questions.

True Sustainability is the ability of a community to be able to meet all of the needs of all of it's population in less than 24h/d/ca, using the skills of that population and the resources/ecological services of the portion of the globe that the community manages, in perpetuity.  Not all the needs must be met, but all of the needs must not be prevented from being met. 

It is not a buzzword, but it has been used by many who want to show that what they are doing is on the side of the angels, without them knowing enough about it to be able to make that statement.  Because academics often get trapped in their 'Ivory Towers', they can lack the perspective needed to see the whole picture.  The focus has tended to be on 'relative sustainability', and incremental improvements in one narrow discipline, without ensuring the whole is advanced.

You list several tools.  There are many more.  All tools are some combination of 3 categories. 

The first includes TBL or PSM II - these are balance approaches.  They want to show how the project/process/product compares to some baseline (often 'do nothing').  In a world that is over-capacity, do nothing is not sustainable, so this comparison can only be said to determine 'less unsustainable', or even 'least unsustainable', but not 'is sustainable'.  Balance approaches are good tools for system managers, but are poor to compare one system to another.

The next includes LEED or Living Building Challenge - these are criteria approaches.  Points are assigned for making different performance outcomes, and the combination that presents the highest number of points is the preferred alternative.  The weighting of the points, and the categories themselves, are developed by academics for a particular setting (western culture, temperate urban, for example).  There is no guarantee that the points are appropriate for your particular setting.  Criteria approaches are good tools to compare related projects, but can't be used to compare unrelated ones for allocating resources (running a railroad, vs improving health care). 

The last is actual measurement.  Think of an airplane.  There may be 140 indicators on the dashboard that allow the pilot to fly the plane from one runway to another.  Not a single one was used by the designer to draw the blueprints of the plane.  The designer understood how every design decision affected the equation relating lift, thrust, drag, weight, and acceleration, to ensure the completed system is able to operate within it's performance envelope.  To apply this to Sustainability, one has to set aside all thoughts of indicators, indices, and metrics, and determine what it is that we need to achieve, and then measure that.  Predict how that would change with each design decision.  Ensure the performance envelope is being met.  Find the alternative that provides the best combination of cost and utility.

This means instead of relative sustainability, one has to work with Absolute Sustainability.  I've attached a paper I co-wrote on the subject.

Sustainability is further related to the restoration of carrying capacity of polluted or depleted environmental sources, in order to meet the needs of future generations. The complexity in conceptualization and the wide diversification of various attributes to "sustainability", such those noted as: " LCA , S-LCA, EIO-LCA , TBL , sustainable reporting", are actually reflecting the "ways of operation", the "methodological tools", or the "managerial practices" at an anthropocentric context of reference which aims to accomplish personal development, economic growth, and human prosperity. In defining "sustainability" and delineating its physical boundaries, it is an imperative need humans to be environmentally conscious and perceive the antagonistic or synergistic impacts of their intervention in nature, at a proactive, no post-treatment, policy planning.

Sustainability is a practical option for manged solution of any problem for perpetuity. As told the concept first applied to forest resources way back but since last century we are focusing sustainability in all spheres of human life and so we have 17 SDG by global forum. It means it has role so we are thinking in this era of climate change. If we would not have threat from climate change the pace might have slow for adoption of sustainable approaches to restore planet earth for future.

Sustainability refers to effective usage and management of an environmental resource to meet current needs without impeding the ability of future generations to meet their needs with the same resource bearing in mind that the environment itself should not be adversely affected.

Your real question would seem to be whether the burgeoning collection of assessment "tools" actually improve resilience, or are simply a paper drill. I'm afraid I see entirely too much of the latter. Unless developers have genuine interest in ecosystem services impacts, plus the freedom to act with integrity and employ those who understand those impacts, "sustainability" at best becomes an excercise in assessing energy efficiency and construction materials operational costs, and at worst is no more than an expensive paper drill. ,

It is not a theory. It is a scientific fact.

There is a phrase 'Think Global, Act Local'. All actions must be local in nature, if for no other reason than I have no idea what it the reality on the other side of the planet. If everyone acts locally to make their system sustainable (ecologically and socially), then we will have achieved global sustainability. It is not possible to achieve, as you say Kenneth, from a top-down global perspective.

I don't think anyone is advocating the top down perspective. No one is saying 'plant bamboo everywhere, because that the right answer'. I'd laugh here, and say "Winter= no chance". Some global agencies are advocating that something has to be done, but whether that is a moratorium on harvesting whales, or raising alarm about climate change, those are not the problems - those are symptoms of the problems. I see nothing wrong with global agencies identifying symptoms of problems, that then local initiatives would seek to solve in their own unique ways.

Climate change is a symptom of exceeding the local ecological services' capacity to absorb waste materials from our industrialized societies. If we ensure our ecological footprint is smaller than our biocapacity in each biome, at every scale, we solve the problem.

Population growth is a symptom of changing pattern of birth and death that will exceed the local ecological services... hey, wait, that sounds familiar. So both of these symptoms come back to the same cause - we are overtaxing our ecosystems. Oh, so the solution of the underlying problem will need to consider both of these symptoms, but the actual solution is likely to resolve both of these symptoms.

Lets check other symptoms: Poverty occurs when individuals, families, and communities do not have access to sufficient resources to be able to meet all of their needs in 24 hours per day. We can attempt to provide access to additional resources (resource development) or to use them more efficiently (technological development). Another solution is to identify and remove the obstructions within the self, family, and community that prevent people from meeting their needs effectively (human development). All three approaches a will ensure that more needs are met. In areas that have an ecological footprint significantly smaller than their biocapacity, resource development and technological development are both great ideas. In all areas, human development will be beneficial. Because it will increase quality of life without a corresponding increase in demands on the local ecological services.

Part of the reason that Sustainability is considered a Wicked Problem is that we are really bad at mixing up the symptoms and the problems, so that we can't see the forest for the trees. If I find a way to remove all excess carbon from our emissions, will we be sustainable? No, there are too many other issues. If we are sustainable, will all excess carbon be removed from our emissions? Probably, but that won't eliminate the excess CO2 from the atmosphere. OK, so the carbon in our emissions is a symptom, and not the underlying problem. Lets try that with Poverty - if we eliminate poverty, will we be sustainable? Not necessarily. If we are sustainable, will we eliminate poverty? Hmmm... Probably, although perhaps we could only say we would reduce poverty to an absolute minimum - I think the jury is still out on that. OK, then poverty is closer to the root of the problem than climate change.

I would suggest that this process can be used to pare down to the underlying problem, and that would be that the process of trying to increase affluence is overtaxing the ability of our ecosystems to provide the ecological services we have grown to rely on to maintain the affluence we already have. Eliminating affluence will not eliminate poverty, but reducing the dependency on the concept of economic growth can allow a reduction in disparity, and that will do more in increasing long-term quality of life than any form of technological development.

Dear Friends and Colleagues of RG,

Sustainable pro-ecological development is a must, a challenge for humanity to be quickly implemented to slow down the global warming process. Sustainable pro-ecological development is a necessity for humanity to avoid annihilation resulting from an increasingly faster global warming process and forecasted increase in the scale of climatic cataclysms that may occur at the end of the 21st century if global ecological innovations, generalized renewable energy are not realized on a global scale over the next several decades. source of energy, electromobility will not be developed, increased efficiency of waste segregation, recycling, etc.

In reality its still in an embryo stage

It is undoubtedly a good option, but I also agree with the explanations as highlighted by Dr Abhijit Mitra.