Here we need to be able to explain in some (but not too much) detail the science
ID: 286370 • Letter: H
Question
Here we need to be able to explain in some (but not too much) detail the science behind global warming. OUCH! How do you do that in a couple of pages? Kind of hard, huh? But we need to be able to do this, because we have to be able to explain to our friends and co-workers how the global ecosystems work, and how they will change if we keep warming the planet through greenhouse gas emissions. And we need to understand why these changes will be harmful not only to the animals that currently exist, but to our own species as well. So the assignment for this week is to do that – explain how our planet functions as one big ecosystem. Or, to think of it another way, you are going to try and explain how everything is connected. In order to do that, read through each short chapter in part I, and then write a brief answer to the main question for that chapter below (short paragraph, 3-5 sentences). Use specific information from the book – facts, figures, concepts – to answer. Then at the end you will try to put it all together.
Gaia – what is the main idea behind the Gaia concept? How does it point us to thinking about Humans as part of the natural world rather than distinct from it?
The Great Aerial Ocean – how do the gasses in the atmosphere interact to help the planet breathe? How will adding extra carbon and other greenhouse gasses alter that system and harm the ecosystem we presently live in?
The Gaseous Greenhouse – what is the basic carbon cycle of the earth? What are “carbon sinks” and how are they related to this cycle (explain using the carbon kidney of the ocean). What happens to these sinks as more greenhouse gasses are put into the atmosphere?
The Sages and the Onion Skin – how does solar radiation affect the planetary ecosystem?
Time’s Gateways – how have the past shifts in climate influenced the planet? How can our present time period cause the same kind of dramatic shift (i.e., what are Humans doing to cause a time gateway)?
Born in the Deep Freeze – why are Humans and so many animal and plant species today threatened by global warming?
The Long Summer – how has human activity in the past interacted with climate patterns to produce the “long summer”? If Human activity in the past has influenced the Earth’s climate (we are part of Gaia), how might we do it again?
Digging up the Dead – how does the use of carbon added to the increase in population cause global warming?
Explanation / Answer
One ecosystem is any area that happens to have an specific set of features (living species and physical-chemical conditions) that make it significantly different from its surroundings.
When an ecologist tries to describe an ecosystem, he/she has to describe the following sorts of facts:
The set of living species in it, that is, the biocenosis. For instance, in a forest there could be pines, oaks, mice, doves, butterflies, kites, ants.
The set of physical and chemical conditions, that is, the biotope. In a forest: the average temperature in the coldest month, the average temperature in the hottest month, the rainfall rate, the kind of salts that exist in the soil.
The relationships between the living species: the pines holding the nests that doves make, the kites eating the mice, the mushrooms feeding on the fallen leaves.
The relationships between the physical-chemical conditions: how temperatures alter the soil's humidity through evaporation, how wind wears away soil particles.
The relationships between the physical-chemical conditions and the living species: the way in which the animal activity is affected by the day-night cycle, the way in which temperature affects the loss of water vapour by plants through evapotranspiration, the way plants retain the soil particles with their roots and prevent them from being worn away by the wind, the way in which the decomposition of fallen leaves or dead animals adds new salts and minerals to the soil.Global warming is the increase of earth’s average surface temperature and its oceans due to greenhouse gases released as people burn fossil fuels. These greenhouse gases such as carbon dioxide and methane absorb heat that would otherwise bounced off the Earth’s surface. Global warming has emerged has one of the most biggest environmemtal issue in the last two decades.Temperatures are certain to go up further.” It seems that the temperature is rising at a rate faster than ever before. Human activities like burning of fossil fuels, deforestation,industrialization and increased in pollution are considered as few of the factors responsible for rise in global warming.The Gaia Theory posits that the organic and inorganic components of Planet Earth have evolved together as a single living, self-regulating system. It suggests that this living system has automatically controlled global temperature, atmospheric content, ocean salinity, and other factors, that maintains its own habitability. In a phrase, “life maintains conditions suitable for its own survival.” In this respect, the living system of Earth can be thought of analogous to the workings of any individual organism that regulates body temperature, blood salinity, etc. So, for instance, even though the luminosity of the sun the Earth’s heat source has increased by about 30 percent since life began almost four billion years ago, the living system has reacted as a whole to maintain temperatures at levels suitable for life.As one example, it has been shown that cloud formation over the open ocean is almost entirely a function of the metabolism of oceanic algae that emit a large sulfur molecule (as a waste gas) that becomes the condensation nuclei for raindrops. Previously, it was thought that cloud formation over the ocean was a purely chemical/physical phenomenon. The cloud formation not only helps regulate Earth’s temperature, it is an important mechanism by which sulfur is returned to terrestrial ecosystems.It is an extremely thin envelope of gas and suspended particles that encompass our planet. To get perspective on just how thin, there's this very rough equivalency: The atmosphere is to the Earth as an onion's wafer thin outer skin is to an onion. But while it may be just a sliver, it's critical to life on Earth.Without our atmosphere, there wouldn't be rain for our plants and vegetables to grow and feed us. There'd be no greenhouse effect keeping the planet temperate enough to sustain life. There'd be no talking or music-playing because sound wouldn't exist as we know it — without a medium like air, sound waves cant travel and thus don't create vibrations that hit our eardrums allowing us to hear. And there wouldn't be the oxygen to breathe. Energy from the sun that makes its way to the Earth’s surface can have trouble finding its way back out to space. This is because of a natural process called thegreenhouse effect . Without the greenhouse effect, Earth’s temperature would be below freezing. However, Earth’s greenhouse effect is getting stronger as we add more greenhouse gases to the atmospher. And that is warming the climate of our planet.Heat is radiated into the atmosphere from the earths surface, which is warmed by sunlight. As the heat makes its way back to space, much of it is absorbed by greenhouse gases in the atmosphere. Greenhouse gases are more complex than most other gas molecules in the atmosphere, with a structure that can absorb heat. They radiate the heat back to the Earth's surface, to another greenhouse gas molecule, or out to space. Sometimes during this Century, the amount of the greenhouse gas carbon dioxidein the atmosphere is expected to double. Other greenhouse gases like methane and nitrous oxide are increasing as well. The quantity of greenhouse gases is increasing as fossil fuels are burned, releasing the gases and other air pollutants into the atmosphere. Greenhouse gases also make their way to the atmosphere from other sources. Farm animals, for example, release methane gas as they digest food. As cement is made from limestone, it releases carbon dioxide.