1. Mother Earth has its limits; Increasing of
human population and pollution
Žiga Ogorelec
Study: Biology
Slovenia

2.  World population is higher than ever since the beginning of the enumeration
and is still increasing and with this, also pollution and the influence on the
environment:
 1)if we don’t do anything:
 2)if we reduce our pollution for example for 20%:
  Problem: also if we reduce our pollution, with increasing number of people
there would be in total more pollution. And further on, there would also be an
increase in demand of food, water and living space.

3.  What is the 21st century disaster? What will happen?
 Maybe there won’t be any sudden change! But many disasters have already occured
and some will even increase: in general we face hunger, diseases and an over load of
pollution in the environment
 The risk of an epidemic spread is omnipresent as well as risk of negative effects of
global warming. We can not predict where and when they may happen, but probably
they will affect more crowded areas.
 History: for thousands of years our population was regulated mostly with food
availability (nature way), diseases and also wars
 We don’t have natural predator, with farming we changed food limits, with
enchroachment in habitats of other living organisms we are spreding our living
space limitations.
 Our number is increasing – where are the limits?

4.  When energy is transferred from one to the next trophic level, typically only 10% of
energy is used to build new biomass
 Due to this mechanism there are less primary consumers than primary
producers, less secondary consumers than primary consumers etc.
 Humans are on top of food chain!  big energy consumption
 Example: if we eat shark, this means a lot of thropical levels : phytoplankton
zooplankton  small fish  bigger fish tuns sharks
(1kg of shark ≈ 1oooookg of phytoplankton!)
What can happen?
 Humans have damaged nature over a log period of time but nature is powerful
and always finds a way to heal itself. At one poing it will start regulating our number
(disease, global warming or other disasters). We can chose – wait for the
consequence or ACT

5.  Main problem in third world and border countries: families have too many
children  no money  may misuse children for working; no school
education  hunger and disease.
 Also in countries where food and education is available:
quantity can decrease the quality of life!
 Governments should support small families, up to 2 children. That wouldn’t
only establish our number, but also bring many benefits:
 Minimizing the consumption of water, energy and fuel
 less industry, transport, CO2 emission and other pollution
 enough food and living space
 smaller families with better life

6.  Why algae?
 Availability of essential nutrients
 Fast growth
 Space saving
 Usage as biofuel
 Why less meat and more plants?
 Ecological pyramid - 90% or more of energy is lost when moving to next thropic level.
( 100g meat ≈ 1kg of plants (with the same nutritional value))
 A lot of plants are planted just for feeding animals  with reduction of meat-eating we
can also reduce the surface of growingfields  less pesticides, less cuting trees for forming
farms, more space for endangered species, etc.
 Biologicaly, humans are omnivores:
- People consume too much animal products (meat, eggs, milkproducts etc.).
- Aftereffects are: overweight, diabetes, vein and cardiac diseases, etc. Many animal
proteins and fats aren’t so healty as plants.

7.  There are many ways how to reduce our bad influence on environment.
Examples:
 Changing people habits (electricity usage, fuel and water
consumption, procesing chemicals, driving with car,…)
 Improving techniques in seperation and recyclating of waste products
 Using biodiesel from algae, using gass from wastewater treatment plant
 Alternative electric generators (wind power plants, hydroeletric plants, solar
panels,…)
 Passive buildings (good insolation, sun collectors,…) + grass (or other plants)
on roofs  increasing green surfaces  positive effect of plants (O2
release, absorbtion of CO2 and pollutats) - important especially for bigger
cities
 A possible option: Water treatment
Water treatment is one of most important acts to protect nature
from pollution. But building wastewater in every small city and village
is expensive. The solution for it is phytoremediaton

8.  How does it work? (see shema)
 In the first pond there is sedimentation of solid/suspended solids
 In the second pond there are plants important for phytoremediation. With
their roots associate many microorganisms (forming biofilm). Plants and
microorganisms together remove rest of pollutants with different
processes (bioaccumulation, biotransformation, etc.)
 Why ponds with plants?
 Many smaller urban areas don’t have any wastewater treatment
 Unexpensive to build ponds and plant plants
 Effective in water treatment

9.  Public awareness campaign is an important factor when we want to make
changes. But in today’s world, for real changes money issue is a matter of
concern.
 1: Limitation of our number:
 Governments should financially and with other benefits support small
families (free health insurance, school, etc.). Families with more than 2
children should pay this things with their own money. (These laws should
of course be valid only for new families and not for families which already
have more than 2 children )
 This also shouldn’t be valid for; countries that have negative population
growth and tribes which live in natural way.
 Gynecological examination and contraception should be free
 2: More plants and algae, less meat
 Grants and lower taxes for farms with vegetable, fruit, higher taxes for
farms with animals.
 Hunting smaller fish instead of tunas, sharks, dolphins etc.

10.  3: Pollution reduction and remediation; building small ponds with
plants
 Because they are not expensive, they could be build in urban areas where
there are no wastewater treatment plants. Once built, there is no additonal
work, natural processes remove pollutants from water.
 Once or twice a year there should be made control and measurements.
 If needed there could be excavation of polluted clay that was formed
during sedimentation process. It can be transported and treated in bigger
waste treatment plants.
 Plants are also bioindicators – if there would be mass pollution, plants
would die (bioaccumulation of pollutants in plants). In this case, people
would see that something is wrong and could act. It is also much easier to
replace plants in pond then remediate polluted environment.
With limitation of our number growth and with reducing of our effect on
environment we can coexist with nature without harming each other.
Because we don't think about future generations, they will never forget us. (Henrik
Tikkanen)