The current world population is 7.9 billion people. Our demands are already making a massive impact on the earth. Global warming, biodiversity loss, resource depletion, these are all symptoms of a bigger problem, human numbers and excessive consumption. Given our impact on earth now we have to reduce our numbers rapidly. We don't have time to wait until 2100 for numbers to decrease gradually. After looking at all of the issues surrounding the population debate, The Depopulation Imperative argues that to achieve any reduction we need a profound moral change from an emphasis on the priority of the human to a new basic moral principle that puts the earth first. While the implications of this principle are radical, in the end the book argues that we can do it and there are grounds for hope.

Discusses how many people the earth can support in terms of economic, physical, and environmental aspects.

This "Little Green Book" presents 21 proposals for reducing the size of the human population to 1 billion people, in order to enable humanity to live sustainably on Earth. For centuries and millennia, humans have exploited the inherited riches of the Earth without significant observable permanent harm. The Industrial Revolution, which used non-human, non-animal power sources to accomplish tasks, began in the 18th century in Europe and North America. In the early 19th century, that power increasingly came from the burning of fossil fuels, primarily coal and oil, and that burning created carbon dioxide. The ills of fossil fuel burning were compounded by population growth. Around the beginning of the 19th century, medical and nutritional advances led to the reduction of the death rate and populations began to grow more rapidly. This change can be said to be the beginning of the Demographic Transition, which is defined as the period during which there is a large gap between the declining death rate and the subsequent reduction of the birth rate which typically occurs several generations later. Proposed here are additional stages of the model to show a Sustainable Demographic Transition (SDT) to a human population of 1 billion, which was the population of the Earth around 1800. The question posed in this book is whether the human birth rate can be reduced soon enough to avoid much of the potential further damage to the Earth, and reduced further to enable remediation of previous damage. The year 1800 is chosen in this book as the pivotal year for the Industrial Revolution and Demographic Transition. At that time, the carbon dioxide density in the atmosphere was approximately 300 parts per million. During the subsequent 215 years, the Industrial Revolution accelerated and, together with exponential population growth, has degraded the ability of the Earth to sustain life. Whatever damage to the Earth the Industrial Revolution would have produced for a planet supporting one billion humans, that damage has been multiplied, so far, by the growth of the human population since 1800 to 7.3 billion by mid-2015. If not stopped, the multiplier will continue to grow. Even at the current and seemingly slow annual growth rate of 1.2%, the Earth's population will double to 14.6 billion in 58 years. Such a total is inconceivable, and avoidable. There has been debate about whether the sheer number of people is the problem or whether their unequal or excessive consumption patterns are the problem. The problem with that debate is that it poses a false choice, which need not be resolved here. That is, while there is no question that there is substantial inequality among people of income and wealth and therefore, of Earth-degrading consumption, there is also no question that every human being has an impact on the Earth. Putting it simply, more humans produce more carbon. Further, more humans have produced too many more humans. There are two basic elements of each human's impact on the Earth. First s/he consumes energy and resources, and s/he has the capacity to have children. Whatever the world's consumption patterns, there will be less consumption and Earth degradation when there are fewer people. This truth is a corollary to the message of population stabilization advocates since the 1970s - "Whatever your cause, it's a lost cause until we control population growth." The first of the 21 proposals is that all humans be encouraged to have no children, or at most, one child. The alternative to achieving population reduction through voluntary means is to endure catastrophes and collapse and gross reduction of biodiversity.

The Earth's population, currently 7.2 billion, is expected to rise at a rapid rate over the next 40 years. Current projections state that the Earth will need to support 9.6 billion people by the year 2050, a figure that climbs to nearly 11 billion by the year 2100. At the same time, most people envision a future Earth with a greater average standard of living than we currently have - and, as a result, greater consumption of our planetary resources. How do we prepare our planet for a future population of 10 billion? How can this population growth be achieved in a manner that is sustainable from an economic, social, and environmental perspective? Can Earth's and Society's Systems Meet the Needs of 10 Billion People? is the summary of a multi-disciplinary workshop convened by the National Academies in October 2013 to explore how to increase the world's population to 10 billion in a sustainable way while simultaneously increasing the well-being and standard of living for that population. This report examines key issues in the science of sustainability that are related to overall human population size, population growth, aging populations, migration toward cities, differential consumption, and land use change, by different subpopulations, as viewed through the lenses of both social and natural science.

The choices we make over the next few years will resonate for decades, and perhaps centuries. This is because our world is at a critical turning point in history, as old certainties are swept aside by a global pandemic, climate change and political upheaval. How we respond to these challenges will determine whether we usher in a new Age of Enlightenment, or a second Dark Ages. In this compelling book Mark Roeder makes sense of our predicament, and explains why we must reconsider some of our most fundamental beliefs. Our current path is not sustainable – socially, environmentally or economically. We are literally devouring our planet, and our communities are becoming more polarised and fearful of the future. The time has come for us to make some bold changes to the way we live. This book explains what these changes should be, and how to implement them.