**2. Living in Interesting Times: Planetary Sustainability Challenges**

We live in "interesting times", where such period refers to—as in the legendary Chinese curse—a time of danger, uncertainty, and complexity [21]. Unless the underlining drivers behind such dangers, uncertainties, and complexities are not eliminated or brought to a manageable level, these interesting times might coincide with the end of human civilization [22]. The primary underlining reasons—which are the key challenges of humanity today—include: (a) rapidly increasing global population; (b) rapidly depleting natural resources and climate change; (c) technological inequality and disruption; (d) misuse of data and information; (d) ruthless neoliberal economies; (e) global, regional, local conflicts; (f) corrupt or ineffective governance. These challenges are illustrated in Figure 1, and further elaborated below.

*Rapidly increasing global population:* With the appearance of *Homo sapiens*, the origin of humankind goes back to about 300,000 years ago. However, it is only during the last 10,000 years that we have managed to establish safer living conditions thanks to progress in the spheres of technology, knowledge, and wisdom. Subsequently, in the year 1800, the world's population reached the one billion mark. During the same year, London was the only city in the world hosting a million people. Today over 220 years later, our population is over 7.8 billion, and London is home to 9.3 million people. But, London is no longer the largest city in the world. The metropolitan region of Tokyo is approaching 40 million people, and there are over 30 other megacities around the world with over 10 million people. Population projections suggest that by the end of the century the global population will range between 9 and 12 billion. Along with megacity developments, all major metropolitan regions are also experiencing rapid peri-urban expansion [23]. This dual human–urban growth is causing alarming water, food, and energy insecurity [24–26].

*Rapidly depleting natural resources and climate change:* Ever increasing populations, coupled with unsustainable development practices, are pushing the limits of the world's carrying capacity [27–30]. Heavy fossil fuel dependency and limited clean-energy options—only about 25% of all the world's energy comes from renewable resources—together with various other contributing factors, are triggering

biodiversity loss and anthropogenic climate change, and increasing the frequency and severity of natural disasters dramatically [31–33]. *Sustainability* **2020**, *12*, x FOR PEER REVIEW 3 of 24 triggering biodiversity loss and anthropogenic climate change, and increasing the frequency and severity of natural disasters dramatically [31–33].

**Figure 1.** Key global sustainability challenges (Source: Authors). **Figure 1.** Key global sustainability challenges (Source: Authors).

*Technological (or digital) inequality and disruption:* Whilst there have been many positive technological inventions and developments, technology also creates disruption in our societies particularly for those who cannot afford, access or adopt new technologies [34,35]. For instance, despite the fact that there are four billion smartphone users in the world, not everyone has access to the internet and mobile services at the same speed and bandwidth [36]. Particularly from an urban perspective, expensive urban technologies are often unevenly distributed across cities, thus contributing to the fracturing of urban societies and to the formation of high-tech *premium ecological enclaves* where only rich minorities can shield themselves from the burdens of climate change and *Technological (or digital) inequality and disruption:* Whilst there have been many positive technological inventions and developments, technology also creates disruption in our societies—particularly for those who cannot afford, access or adopt new technologies [34,35]. For instance, despite the fact that there are four billion smartphone users in the world, not everyone has access to the internet and mobile services at the same speed and bandwidth [36]. Particularly from an urban perspective, expensive urban technologies are often unevenly distributed across cities, thus contributing to the fracturing of urban societies and to the formation of high-tech *premium ecological enclaves* where only rich minorities can shield themselves from the burdens of climate change and environmental degradation [37–39].

environmental degradation [37–39]. *Misuse of data and information:* During the last two decades, with the raise of the second digital revolution and mass digitization, data and information have become more widely and easily accessible. Especially social media platforms and shared user-generated contents have provided large volumes of data. Nonetheless, this has also led to fake news and data integrity issues [40]. Furthermore, targeted Facebook and WhatsApp campaigns changed the results of the 2016 USA and 2018 Brazil presidential elections, and the 2016 Brexit referendum [41–43], thereby showing how data *Misuse of data and information:* During the last two decades, with the raise of the second digital revolution and mass digitization, data and information have become more widely and easily accessible. Especially social media platforms and shared user-generated contents have provided large volumes of data. Nonetheless, this has also led to fake news and data integrity issues [40]. Furthermore, targeted Facebook and WhatsApp campaigns changed the results of the 2016 USA and 2018 Brazil presidential elections, and the 2016 Brexit referendum [41–43], thereby showing how data is being used not to inform, but rather to misinform and to protect the interests of certain political elites/groups.

is being used not to inform, but rather to misinform and to protect the interests of certain political elites/groups. *Ruthless neoliberal economies:* Today, the world is facing harsh economic challenges. Globally, we are moving towards another recession, if not already in. While some might blame the recent COVID-19 pandemic, the origin of the issue is neo-liberal capitalism and the consumeristic and materialistic practices that it reproduces [44,45] Only eight people, the richest in the world, have a net worth equivalent to that of the lower half of the world's population (about 3.8 billion people); this is the product of ruthless neoliberal economies [46]. Socioeconomic inequality is rapidly widening, and poverty and recession are making life harder for most people across the globe. Particularly with the existing COVID-19 pandemic, the situation is much more dramatic and unsustainable in developing *Ruthless neoliberal economies:* Today, the world is facing harsh economic challenges. Globally, we are moving towards another recession, if not already in. While some might blame the recent COVID-19 pandemic, the origin of the issue is neo-liberal capitalism and the consumeristic and materialistic practices that it reproduces [44,45] Only eight people, the richest in the world, have a net worth equivalent to that of the lower half of the world's population (about 3.8 billion people); this is the product of ruthless neoliberal economies [46]. Socioeconomic inequality is rapidly widening, and poverty and recession are making life harder for most people across the globe. Particularly with the existing COVID-19 pandemic, the situation is much more dramatic and unsustainable in developing countries, and for disadvantaged communities and individuals [47].

countries, and for disadvantaged communities and individuals [47]. *Global, regional and local conflicts:* Human civilization has always experienced conflicts and wars over resources, land, or power. However, contemporary wars are not only taking place as trade, *Global, regional and local conflicts:* Human civilization has always experienced conflicts and wars over resources, land, or power. However, contemporary wars are not only taking place as trade, diplomatic and armed conflicts, but also as cyber warfare [48]. These multiple conflicts, together with

diplomatic and armed conflicts, but also as cyber warfare [48]. These multiple conflicts, together with

climate change, are displacing many people, thus substantially increasing the number of refugees in the world [49,50].

*Corrupt or ine*ff*ective governance:* Governments should have supposedly addressed the aforementioned challenges. Instead, short termism in political circles, corporate influence, and various degrees of corruption make governments unable to be part of the solution [51]. An example is the Paris Agreement on climate change, which, although signed by 197 countries (and ratified by 189), has led to little or no tangible outcome due to government inaction [52].
