Environmental Problems, Their Causes, and Sustainability 1

on which we and other species depend. Second, weneed to slow down the rates at which we are alteringnature for our purposes. If we simplify, homogenize,and degrade too much of the planet to meet our needsand wants, what is at risk is not the resilient earth butthe quality of life for members of our species and otherspecies we drive to premature extinction.What Can We Learn from Ecology aboutLiving More Sustainably? Copy NatureWe can develop more sustainable economies andsocieties by mimicking the four major ways thatnature has adapted and sustained itself for severalbillion years.So how can we live more sustainably? Ecologists say:Find out how nature has survived and adapted forseveral billion years and copy this strategy. Figure 9-14(also found on the bottom half of the back cover) summarizesthe four major ways in which life on earth hassurvived and adapted for several billion years. Figure9-15 (left) gives an expanded description of theseprinciples and Figure 9-15 (right) summarizes how wecan live more sustainably by mimicking these fundamentalbut amazingly simple lessons from nature indesigning our societies, products, and economies. Figures9-14 and 9-15 summarize the major message of thisbook. Study them carefully.Biologists have used these lessons from their ecologicalstudy of nature to formulate four guidelines fordeveloping more sustainable societies and lifestyles:SolarEnergyNutrientRecyclingPRINCIPLESOFSUSTAINABILITYPopulationControlBiodiversityFigure 9-14 Sustaining natural capital: four interconnectedprinciples of sustainability derived from learning how naturesustains itself. This diagram also appears on the bottom half ofthe back cover of this book.SolutionsPrinciples of SustainabilityHow Nature WorksRuns onrenewablesolar energy.Recyclesnutrients andwastes. Thereis little wastein nature.Usesbiodiversity tomaintain itselfand adapt tonew environmentalconditions.Controls aspecies'population sizeand resourceuse byinteractionswith itsenvironmentand otherspecies.Lessons for UsRely mostly onrenewable solarenergy.Prevent and reducepollution andrecycle and reuseresources.Preserve biodiversityby protectingecosystem servicesand preventingpremature extinctionof species.Reduce births andwasteful resourceuse to preventenvironmentaloverload anddepletion anddegradation ofresources.Figure 9-15 Solutions: the four principles of sustainability(left) derived from observing nature have implications for thelong-term sustainability of human societies (right). These fouroperating principles of nature are connected to one another.Failure of any single principle can lead to temporary or longtermunsustainability and disruption of ecosystems and humaneconomies and societies.■ Our lives, lifestyles, and economies are totally dependenton the sun and the earth. We need the earth, butthe earth does not need us. As a species, we areexpendable.■ Everything is connected to and interdependent witheverything else. The primary goal of ecology is to discoverwhat connections in nature are the strongest,most important, and most vulnerable to disruption forus and other species.■ We can never do merely one thing. Any humanintrusion into nature has unexpected and mostlyunintended side effects (Figure 3-4, p. 38). Whenwe alter nature we need to ask, “Now what willhappen?”■ We cannot indefinitely sustain a civilization that depletesand degrades the earth’s natural capital, but we cansustain one that lives off the biological income provided bythat capital.174 CHAPTER 9 Population Ecology