what is the importance of carrying capacity in human communities and please give example to better understand the concept.. thank u
Population is not of concern if there are enough resources to go around. Important resources like water of suitable quality for growing crops, drinking, cooking, and cleanliness, fertile soil for growing food and trees, and fuel for warmth and cooking.
Depletion of important resources leads to poverty, disease, malnutrion and often death. Impoverished people are usually forced to destroy their environment in order to survive.
Sustainability is the practice of conservation that will allow people to have enough resources through their life and the lives of future generations. Sustainability is possible by conserving energy, materials, resources, by new technologies, and by ensuring that the number of births is low enough so that there is enough to go around. Sustainability and Population Karen Gaia Pitts
Sustainability in General
Every day, we are presented with a range of "sustainable" products and activities—from "green" cleaning supplies to carbon offsets. But with so much labeled as sustainable, the term has become essentially sustainababble, at best indicating a practice or product slightly less damaging than the conventional alternative. Is it time to abandon the concept altogether, or can we find an accurate way to measure sustainability? If so, how can we achieve it? And if not, how can we best prepare for the coming ecological decline?
In Worldwatch Institute's newest project, scientists, policy experts, and thought leaders tackle these questions, attempting to restore meaning to sustainability as more than just a marketing tool. Within this website, you'll find State of the World 2013: Is Sustainability Still Possible? -- http://blogs.worldwatch.org/sustainabilitypossible/state-of-the-world-2013/
--, which explores these questions in depth in over 30 articles. As well, you'll find additional essays, videos, presentation materials, news updates, and additional translations of the report. The Sahara Desert, a vast, nearly lifeless expanse of sand and rock was once a fertile grassland and bands of human hunters chased aurochs and antelope, but a wobble in Earth's orbit catalyzed ecosystem changes that caused the Sahara to go from green to brown in a matter of centuries or even decades.
A series of small modifications can push a system to a "tipping point," where it flips, quite suddenly, from one state to another. And many believe that human population dynamics are an increasingly important variable in environmental change, at local, regional, and global scales.
Volcanic eruptions, solar flares, and the clash of continents have changed the Earth, but, since the beginning of the last century, our numbers have quadrupled, reaching seven billion in 2011, resource consumption has skyrocketed, and more people are living in environmentally fragile regions, such as coastal areas, making humans responsible for the more recent changes.
More than 80% of the Earth's land is under direct human control; humans use a fifth of the planet's biomass; humans emit carbon dioxide and other heat-trapping gases which are warming the planet and acidifying the oceans. Because of all of this disruption, we are now in the midst of the biggest wave of extinctions since the end of the dinosaurs.
Environmentalists learned that environmental impact (I) is the sum of population size (P) times per capita affluence level (A) times the impact of technologies (T). Otherwise known as IPAT. But John Harte in A Pivotal Moment tells us that non-linear effects, including thresholds and feedbacks, can amplify the environmental impact of human numbers. For example, a species may depend on a certain amount of intact habitat to survive. As human settlements encroach, a threshold is eventually crossed, and the species will, sometimes quite suddenly (within a generation or two), collapse.
A classic example is the loss of "albedo": on a warming planet, there is less ice and snow to reflect heat back to space, so more sunlight is absorbed by the Earth's surface, which intensifies warming. Another example: warming accelerates the decomposition of organic matter in cultivated soil. That decomposition, in turn, releases carbon dioxide into the atmosphere, which speeds even more warming. Because more people generally means more cultivated land, population growth affects the intensity of this feedback effect.