A Planet of 3 Billion: Mapping Humanity's Long History of Ecological Destruction and Finding Our Way to a Resilient Future A Global Citizen's Guide to Saving the Planet Paperback – August 27, 2019

Chris Tucker 'stalks the wild taboo' by asking the question - How many people can the earth support in a sustainable and desirable way? Many will find the answer (3 billion - no spoiler there) to be challenging. I weigh 215 pounds and should weigh 185. I don't think I should cut my arm off to get there. I should change my behavior and reach that goal. As Yogi Berra said: 'If you don't know where you are going you'll end up someplace else'. Humanity has not collectively decided 'where we are going' and if we don't we'll end up someplace else that will involve a great deal of avoidable human suffering and likely result in irreparable damage to our ecosystems, loss of species, and squandering many opportunities of our descendants. I think Chris Tucker has made a great suggestion as to what our goal should be.

That is what makes this book unique and important.Among demographers it is considered impossible and inappropriate to apply the concept of carrying capacity to humans. Though humans are a biological species like any other, the same rules do not apply, or are impossible to apply because of the variability of technology and culture, or so many think.Christopher Tucker, a geographer -- current Chairman of the American Geographical Society -- throws caution to the wind and makes a calcuation, which is the title of the book.The most interesting and important part of the book is how he makes this calculation. He starts with the "Ecological Footprint" measure of environmental impact, produced by Mathis Wackernagel and the Global Footprint Network, which uses immense amounts of data to show whether a country has a surplus or deficit of biological capacity in land area based on its resource consumption. Summed globally, human society is of course in overshoot -- as of 2017 the overshoot is 50%. We are using 1.5 times the resources that would be sustainable, and the overshoot grows every year.Then he somewhat arbitrarily chooses Switzerland (Wackernagel's home) for the standard of living for humans globally. Using the Ecological Footprint method, Tucker calculates that it would take 3.3 Earths to support the current population of 7.9 billion at the Swiss standard of consumption, and that the Earth can therefore only support 2.4 billion people at that level. Of course this is a comfortable, high income level, though not as extravagant as the U.S. -- it would take 4.8 Earths to support humans at the U.S. level of consumption, and so the carrying capacity would be substantially smaller.This is quite promising given that it would result in a reduction by approximately two thirds of today's 7.9 billion. This is only a balllpark figure given that Tucker's calcuation "assumes today's mix of technologies," and clearly today's mix of technologies is killing the planet, so it would have to be radically changed so as to be less destructive, including phasing out burning fossil fuels. My strong sense, therefore, is that his calculation is too high, especially when he rounds up from 2.4 to 3 billion. Why round up?Of course this is all in the realm of what *should* happen, not what is *actually likely* to happen. Tucker's plan for "How to Bring the Population Down to 3 Billion" simply involves empowering women and speeding up the lowering of the fertility rate, which is already falling everywhere as urbanization spreads. He has nothing to say about the particular challenge of sub-Saharan Africa, which is where the vast majority of 21st century population growth is projected to take place.There is little in the rest of the book that is new or unique. There's nothing wrong with it, but it is mainly redundant -- my apologies to geographers -- leaving only three of the 13 chapters to make an invaluable contribution to solving the ecological crisis.

A Planet of 3 Billion was excellent. Tucker's discussion of population is ground in the context of history, geography and man's behaviors. With detailed research and a sea of footnotes, he makes a case for sustainable population goals. His exploration of man's ecological footprint is frightening in its honesty and he effectively frames a series of arguments that are hard to disagree with and the physical evidence of which we live with on the nightly news. Exceptional in detail and forward looking, I recommend A Planet of 3 Billion to all my fellow humans who care about our future.

And trhe footnotes and bibliography are terrible

A well thought out set of recommendations to make sure we take care of the planet. You can tell that Dr. Tucker has been thinking about this issue for a very long time.

Arrived torn, cover was extremely sticky/dirty/stained. Yuck!

A Planet of 3 Billion provides all most people need to know about the biggest single threat to civilization and other species. The maps are good and the text is generally clear. Minor quibbles about organization should not detract from the importance of the message about the obvious harm caused by way too many humans on this little planet.

A comprehensive and understandable account of the issues facing us including climate change, but embracing others equably important.