There are two main ways that humans can work toward a sustainable level of consumerism at the personal level: stopping population growth and decreasing per capita consumption.
Stabilizing the Earth’s Population
The Earth’s population did not reach 1 billion until about 1800 AD. Since then, the rate of 
population growth has skyrocketed. The second billion was reached in 130 years, and the third in only 30. The rate of growth seems to be stabilizing; since the population reached 3 billion, it has been increasing by one billion about every 12-14 years (Population Reference Bureau 2010). However, it is not enough for the growth rate to be stable—it needs to become zero in order to be sustainable. It doesn’t matter if every country in the world “goes green;” if the global population continues to increase at the current rate, the human race will still be pushing the planet to the limits of its ability to provide for us and for all other species. How can this be achieved?
Not counting immigration, most developed nations are heading towards replacement-level growth (that is, no population growth). In some countries, such as Japan, Germany, and multiple nations in Eastern Europe, the population is actually decreasing (Population Reference Bureau 2010). It is thus developing countries that are exhibiting the highest rates of population growth. Factors contributing to this growth that must be addressed before sustainability can be achieved are:
Getting the human population to a stable point would help slow the conversion of natural areas to agricultural land.
Becoming a “Green” Consumer
In addition to stopping the population from increasing (or at least slowing the growth), people must strive to consume less. If enough individuals make a concerted effort to use less energy and avoid unnecessary waste, this can be a powerful force in influencing the actions of companies that provide goods and energy. In order for a person to act sustainably, however, they must possess both the motivation and the ability to do so. Moisander (2007) conceptualizes how these two components are necessary in producing behavior:
Motivation to Be Green
Motivation can take different forms. One type of motivation may be education about the magnitude of the problem. By becoming aware of how human action is having a destructive influence on the planet, a person may be personally motivated to make changes in their lifestyle. Another form of motivation could be financial incentives for making sustainable choices. It is important to note that what motivates one person or corporation may not motivate another.
Ability to be Green
Making sustainable choices requires knowledge: first, the knowledge that a problem exists, and second, the knowledge of how to engage in sustainable practices. Without this knowledge, people are unable to live sustainably. Thus, education also plays a role in sustainability. In addition, living in poverty hampers a person’s ability to adopt a sustainable lifestyle. If a person’s basic needs are not being met, then it is nearly impossible for that person to be concerned about the future of the planet. Thus, working toward alleviating global poverty and fostering political stability worldwide are crucial in the fight to conserve the Earth’s resources.
