Module VII

Essential Question Redux:

How is Earth's climate connected to its geological, biological and cultural systems?

Earth is made up of varying amounts of the 92 elements on the Periodic Table. Through gravitational forces, fusion and other chemical reactions, the heavier elements that were formed sunk to the middle forming the inner core, which is solid iron and nickel. Temperatures and pressures here are intense. Three more layers top this inner core, the next being the outer core, which is made up of liquid iron and nickel. Next is the mantle. It is made up mostly of solid rock, but it is rock that moves. The rocks lower in the mantle layer are more liquid-like because they are closer to the heat of the core. This property is what allows the tectonic plates to slide. The last and thinnest layer is the crust made up essentially of more rocks, except they are cold and less dense. Then surrounding our planet is the atmosphere, layers of gases that protect us from the heat of the sun. The Greenhouse gases, primarily nitrous oxide (NO2), carbon dioxide (CO2) and water vapor (H2O), absorb some of the heat reflected off the Earth from the sun’s rays. This heat is reflected back to the Earth heating it and making it a habitable place. Greenhouse gases are a good thing, without them earth would be too cold. Cold enough that even the oceans would freeze.

Today many scientists are concerned about climate change or more succinctly global warming. Earth’s temperatures are going up. History tells us that our ever-evolving planet has experienced various times of warming and cooling in its existence and still sustained life, so what is so different this time? The answer is MORE! More CO2 from methane from more cattle and more burning of fossil fuels because there are more people; more carbon in the ocean being absorbed from an atmosphere that now contains 30% more CO2. This 30% more is changing our planet. It is trapping more of the sun’s heat, which in turn affects our climate. This is melting our ice and heating our land so more vegetation grows on the tundra and further traps the heat.

The oceans are absorbing more of this excess carbon too. The ocean contains 65% of the earth’s stored carbon. It is released slowly into the carbon cycle that sustains our life. High levels of carbon in the ocean are harmful to marine life low on the food web such as algae, mollusks and coral. It is easy to see that a decrease of availability of low trophic organisms will affect each higher level.

The connection continues with cultures whose way of life was formed on the climate of the north. Simply put, cold and ice. This temperature change and its effects have living eyewitnesses. Villagers that grew up in the north have seen subtle differences like the sky is less blue to more measurable factors like changing sea ice. Take a look at the video of students in the far western village of Wales, AK, where they interview people who have experienced these changes.

Some of the websites that I looked at this time had some pretty interesting interactive features. I found the Periodic Table site linked above was something I wish I had when I was in college. Using the information on electrons, protons and neutrons allowed you to put the elements in the correct group or period based on their clues. Another website that I plan to explore more in depth is http://www.windows.ucar.edu which seems to have a lot of activities and information for younger students.