What makes sophisticated empires fall? That's the question that one team of scientists backed by NASA's Goddard Space Flight Center tackled in their report, which modeled human interaction with nature to determine what circumstances are constant in the rise and fall of empires over the course of history. Their conclusion is relatively simple: "Two important features seem to appear across societies that have collapsed: (1) Ecological Strain and (2) Economic Stratification."
To conduct their study, the group modeled various scenarios including equal and unequal societies. They created a system of equations called HANDY, or Human and Nature DYnamics, based on the predator-prey model. They found that:
The scenarios most closely reflecting the reality of our world today are found in the third group of experiments, where we introduced economic stratification. Under such conditions, we find that collapse is difficult to avoid.
In introducing economic stratification, the scientists created two classes of individuals: elites and commoners, between which there was an unequal distribution of wealth. The model found that the devastating effects of depleted natural resources hit the commoners first and ultimately wiped out the elites as well. Inaction to avert such disastrous outcomes was furthered by the lag in impact on the two populations. As the report points out:
Elites -- due to their wealth -- do not suffer the detrimental effects of the environmental collapse until much later than the Commoners. We could posit that this buffer of wealth, as well as the initial apparently sustainable trajectory, allows Elites to continue 'business as usual' despite the impending catastrophe.
The report cites examples of the Roman and Mayan empires, which were sophisticated but couldn't avert their own demise. Nafeez Ahmed explains the report's findings in The Guardian in more detail.
The circumstances that the report identifies are not unfamiliar to us today. There is already a strain on natural resources in our society due to high consumption and economic inequality is headline news. Climate change is negatively impacting populations and sectors across the globe.
The global picture of inequality is reflected in our own backyard. The 2014 Silicon Valley Index, a report by the Silicon Valley Community Foundation, found good and bad news. There were increased resource savings when it came to water consumption. In 2013, water consumption was at 136 gallons per person compared to 165 gallons per person in 2001. Additionally, water recycling rose from 1.3 percent in 2001 to 4.1 percent in 2013. However, income inequality has become more pronounced. The report found:
The share of households in Silicon Valley earning more than $100,000 increased two percentage points to 45 percent in 2012, while the share of households earning $35,000 to $99,000 decreased two percentage points to 35 percent.
The report also cited increased housing prices in the region, an indication of an increase in cost of living:
Less than half of Silicon Valley's first-time homebuyers can afford to purchase a median-priced home, compared to 59 percent in the state.
Additionally, inequality affects certain populations disproportionately, and the report found that certain groups were more adversely affected than others:
While unemployment has declined among nearly all racial/ethnic groups in Silicon Valley since 2011, it is still over 10 percent for African Americans.
According to the same report, the regional unemployment rate in November 2013 was 5.3 percent. The report further noted that generally speaking, "Income disparities persist between racial and ethnic groups. The lowest-earning racial/ethnic group earns 70 percent less than the highest earning group." There is also a gender imbalance: "Males with a Bachelor's degree or higher make 40-73 percent more than women at the same level of educational attainment." The report further noted:
The difference between individual median income for men and women is most striking for those with graduate or professional degrees, in which case men in 2012 were earning 73 percent more than women. This percentage is down from a striking 97 percent in 2010, meaning that men with graduate or professional degrees in Silicon Valley were earning nearly twice that of their female peers.
The geographic focus for the report was only in Silicon Valley. However, income inequality is also a growing concern in San Francisco and other cities such as New York, Boston, Detroit and Miami.
This data combined with the scientists' findings suggests that we're on our way to collapsing if we don't address these circumstances. In their discussion, the report's authors note that policy changes that attack inequality and resource depletion can avert collapse:
Given economic stratification, collapse is very difficult to avoid and requires major policy changes, including major reductions in inequality and population growth rates.
The authors are clear that minor changes won't do. This is hardly an easy task, but certainly one worth undertaking. What is optimistic for us is that there are people sounding the alarm and advocating for a change in policies so that we don't continue the trend of increased inequality that we're on. However, these circumstances require more than an alarm. They require action that is quick and effective, nationally and internationally. As the report notes:
The fall of the Roman Empire, and equally -- if not more -- advanced Han, Mauryan and Gupta Empires, as well as so many advanced Mesopotamian Empires, are all testimony to the fact that advanced, sophisticated, complex and creative civilizations can be both fragile and impermanent.
We can join their fate or use the tools we have to change course. Considering the innovation and human capital we have, it would be a shame not to use it to secure our own future.