Environmental Systems

Dear friend:

This first semester at UdeM was awesome! I have learned a lot in all of my courses. One of my favorites is Environmental Systems. I’d like to tell you all the great and interesting stuff I now know. On my first month, my teacher thought us what was this science about, it’s the study of how humans interact with the environment. Isn’t that interesting? This science’s goal is tounderstand and solve environmental problems caused by human activities considering other sciences like: biology, social studies, chemestry, physics, earth science, economical studies, etc.

Environmental problems are global, whatever we do to our environment locally, eventually, affects the environment globally. An example of this, my friend, is the global warming. Pollution is an undesired changein air, wáter or soil that affects the health, survival or activities of humans or other organisms. You should know buddy that the major forms of pollution is on water, air, soil, radioactive, visual, noise, light and termal.

The ozone depletion is when the chlorine ato mis removed from the CFC(chlorofluorocarbon) and attracts one of the three oxygen atoms. Another concept that I learned isthe green house effect. It’s gases make the Earth 18ºC warmer and they are mainly concentrated on water vapor, carbon dioxide, methane, nitrous oxide and the CFC’s. All of this is air pollution.

Now, the water pollution is mostly as consequence of domestic sewage, which occupies a 50% of this type of polltion, 25% is erosion, 12% phosohates in detergents, 8% pesticides and 5% leaded gasoline. Iwas really surprised when my teacher talked about eutrophication, I didn’t knew this exists! It’s a process where water bodies receive excess of nutrients, typcally compounds containing nitrogen or phosphorus, that stimulate excesive plant growth. This enhaced plant growth often calle dan algal Bloom, reduces disolved oxygen in the water when dead plants decomposes and can cause other organisms todie. This is a huge problema, don’t you think? This excess nutrients come, in a natural way, as erosion of soil containing nutrients, and as an antropogenic way, as fertilizers and sewage.

Soil pollution is caused by the presence of human-made chemicals or other alteration in the natural soil environment. Some soil pollutants are heavy metals and their compounds, organic chemicals, pesticides,explosive and toxic gases, radioactive materials, biologically active materials, nitrates and phosphorus. That’s a lot! All these substances commonly arise from the disposal of industrial and domestic waste products in designed landfills or uncontrolled dumps. There are many horrible consequences to this type of pollution, I was horrorized! I’ll tell you some of this consequences, so you’ll knowhow serious this problem is. Lead in soil causes brain damage in young childen, mercury can cause damages in kidneys, neuromuscular blockage and depression in central nervous system; headaches, nausea and finally, skin rash.

I just realized I haven’t started from the beginning. In order to understand all what I’ll tell you about in this letter, you should know that Earth is an integratedsystem that consists of rock, air, water, and living things. Scientists divide this system in four parts: lithosphere/geosphere (rock), atmosphere (air), hydrosphere (water) and biosphere (living things). All of them interact with each other, and I’ll tell you the most important of each one of them.

Geosphere or Lithosphere, is the layer of land that forms Earth’s surface, Hydrosphere is the partsof Earth that are made up of water, this includes: oceans, lakes, rivers, underground water, clouds in the air, etc. Some important facts are that water stores heat, regulates surface temperatura and it’s on living things. 70% of Earth’s surface is covered with water ( more than 97% is saltwater, the rest is fresh water) Most of our little quantity of freshwater is, sadly my friend, on the ice....