Yes, I see you found an equation. That equation has been used to try to scare the shit out of everyone since the 1960s because the deacons of the faith have found that people will believe anything if there is a formula involved.
I well remember the 1960s. At a world population of about four billion, the movement you now accept without question really got its start by predicting that humanity's overpopulation and overuse of resources would deplete the planet's resources and cause mass famine within the next decade. They keep slipping their predicted date of armageddon as the last predicted date passes with the planet in no worse shape (in some ways in better shape). The predicted date of armageddon continued to slip as later predicted dates passed without finding us all starved to death. It now looks like they decided to jump thirty years to 2050 to save themselves the embarrassment for a while - well maybe Ehrlich decided to move the date to until well after he died.
A question, did you bother to actually accept my challenge and do a little check to see how much water flows from the Planet's rivers each day and compare it to human use of water? Or did you just blindly accept the claim by the movement that humans will soon deplete the planet's water supply?
It's not just the formula. You can ignore the formula if you like, it won't change the evidence for the rate of degradation of ecosystems, clearing, habitat loss, etc, at our current rate.
Now imagine this activity in relation to rising living standards in terms of 10 billion inhabitants. Think in terms of 10 billion people consuming resources on a par with the average American, Englishman or Australian.
If you are realistic, it's not a pretty picture. It is a picture of humanity living on the edge of catastrophe.
Food security
Experts agree the planet can produce enough food for 11 billion people, but whether humans can do it sustainably, and whether consumers will ultimately be able to afford that food, are not guarantees.
Water security
Today, 2.7 billion people around the world face some water shortage in their daily lives. Clean, fresh water is a source of conflict in the U.S. Southwest, the Middle East and sub-Saharan Africa. Most people expect these conflicts to grow in the coming years. But these water woes are just a foreshadowing of the problems to come if the world's population hits 11 billion people by the end of the century, which will make providing clean water for everyone an increasing challenge.
In order to meet this challenge, scientists will need a better estimate of how much water is available, and people will need to invest in efficient water infrastructure and employ water-sparing farming techniques around the world, experts say. But even that may not be enough to provide for a thirsty planet. Some regions of the world may have to stop producing water-hungry crops and products altogether, leaving that to countries with more ample water supplies.
The world's food security future is not a simple matter of producing more food. Rather, food security is affected by a number of intertwining factors, including population size, climate change, food production, food use (for things like animal feed and biofuels) and prices, experts say. The world's population will also have to pay close attention to its use of Earth's resources, or risk making the situation worse.
Climate Change
If greenhouse gas emissions continue to rise, and the global population swells to 11 billion people, could this growth worsen the effects of climate change, and overwhelm humanity's ability to fight global warming? Within the scientific community, this debate is brewing, but there is little consensus about how — or even if — population growth and climate change are directly linked.
Earth's animals
Growing human populations spell trouble for animals, and people are in the midst of driving the sixth-largest mass-extinction in the history of Earth, most biologists say. In general, conservationists and scientists are extremely worried about what the world's animal populations may look like if the human population grows to 11 billion.
Population growth is leading to destruction of wildlife habitat, and increasing demand for wildlife products. Some good news is that the richest animal diversity is found in a few spots, which could make conservation of these vital places easier. But it has to be made a priority, which is often not the case, scientists say.
Population growth is expected to surge in developing nations, particularly in sub-Saharan Africa. These regions have much smaller carbon footprints than developed countries. But, some climatologists say rapid industrialization of developing nations and changes in their consumption levels could add stress to Earth's fragile ecosystems.
