I am of the belief that Global Warming is a scientific reality and that its current cause is primarily due to unsustainable greenhouse emissions from man. I am equally convinced that it is still within our power to stop it before it become too big for man to reverse its course. There are still many primarily political and social conservatives as well as scientist who either are in total denial about Global Warming or who believe that it is just another ice age cycle which man’s emissions of CO2 play little or no role. In fact the vast majority of climate scientist and a great majority of physical scientist, whose ranks continue to grow, believe that Global Warming is real and largely man caused (anthropogenic). Ice core samples from different parts of the earth have mapped the levels of CO2 in our atmosphere going back more than 400,000 years and many ice age cycles providing compelling evidence that our current increasing CO2 concentration trends do not follow the typical ice age cycle. Core samples show cyclical CO2 ranges alternating between 180 ppm to 300 ppm representing average global temperature fluctuations of +/- 5 OC. Current levels of CO2 is 400 ppm and rising with no signs of reversing. But what is most alarming to scientists is that the rate of increase since 1800 (the industrial revelation) when CO2 concentrations were 280 ppm to the present day has no precedence. All prior ice age cycles were much more gradual. So the scientific evidence is quite overwhelming.
This article is primarily my view of things to come, based upon my limited knowledge about climate and weather science, if not enough is done to curb Global Warming. Logical and scientific explanations and analogies are given for every aspect of this article in easy to understand language. I start with the 5 basic fundamentals of weather and climate change as a foundation to give the reader a better understanding about the subject.
Fundamental 1 – The Greenhouse Effect
We have all experienced the greenhouse effect when getting into our cars on a clear day with the windows rolled up. The interior of the car is much hotter than outside. The interior materials of the car produces heat from the shorter wavelength infrared rays of the sun that penetrates your car’s window. This heat is actually a longer wavelength form of invisible infrared light. These heat rays that reach the glass windows reflect back into the car’s interior like mirrors since long wavelength infrared rays cannot penetrate glass (or elevated levels of green house gases). The heat has nowhere to go so it accumulates inside the car making it hotter. Metal parts inside the car carry some of the heat to other parts of the car. The glass windows also heat up from the interior hot air and conduct some of the heat through the bulk of the glass back outside the car. Otherwise the car would continue to heat up until it melted or burst into flames.
The name greenhouse comes from greenhouses made of glass for keeping plants warm in winter which were in wider use a hundred years ago. Carbon dioxide (CO2) and other greenhouse gasses such as methane have similar properties to glass such that they are transparent to the shorter wavelength infrared light coming from the sun but reflect the longer wavelength infrared rays from the heated ground back towards the ground. Higher concentrations of greenhouse gases reflect more heat back to the earth. Since our atmosphere has no boundaries this greenhouse warming phenomenon is global. I refer to human generated greenhouse gases as Primary Sources because they have the most significant effect on Global Warming.
Fundamental 2 – Heating Properties of the surface of the Earth
The earth does not absorb all the infrared rays. The surface of the earth reflects a certain percentage of the rays back into space depending on how reflective the surface is. Snow is white and reflects most of the sun’s rays. Snow melts more from the heating of the air around it than from the sun’s rays. The natural colors of land absorb roughly half the sun’s rays and reflects the other half. Most of the sun’s rays heat the ground only a few inches to a foot deep due to its insulating properties making it much more concentrated and hotter than the surrounding air. Our paved black roads absorb almost all the sun’s rays and can generate a lot of heat because of the amount of the sun’s energy convert to heat. Oceans also absorb most of the sun’s rays but since it penetrates below the surface some distance the heat it dispersed over a larger volume. Water, being very mobile, carries the heat even deeper into the ocean. Thus water is much cooler than land where heat is more concentrated at the surface. Water plays a major role in Global Warming because it covers ¾ of the earth’s surface and is so mobile. Generally darker surfaces absorbs more of the sun’s energy than lighter surfaces and converts it to heat.
Fundamental 3 – Science of Carbon Dioxide (CO2) in Atmosphere
CO2 is a colorless, odorless, and nontoxic gas that is a major byproduct of most forms of combustion such as burning, running a car, generating electricity with hydrocarbon and fossil fuels, etc. Air consists of about 21% oxygen but almost no CO2. The current level of CO2 in the atmosphere is about 0.04%. Scientist express the concentration of CO2 in our atmosphere in parts per million (ppm) since it is so low. The reason for this is that at these levels it is quite soluble in water, somewhat like carbonated beverages, which absorbs most of it from the air. Water absorbs more CO2 as it cools down and locks it into ice crystals when it freezes. High concentrations of CO2 exist deep under the ocean where it is very cold and pressures very high like refrigerated carbonated beverages in a closed can. Our huge oceans are very effective at storing vast quantities of CO2. Warming water is unable to holds as much CO2 as cold water releasing it back into the atmosphere. I refer to CO2 that returns back into the atmosphere from water and ice as Secondary Sources. Thus Primary Source global warming by people can actually cause a Secondary Source chain reaction of even more CO2 being released from the warming oceans accelerating global warming. Because of the effectiveness of CO2 as a greenhouse gas even small increases in atmospheric CO2 concentration can have major effects on the amount of heat reflected back to the atmosphere near the earth’s surface. Prior to 1800 CO2 concentrations were about 280 ppm. Current levels of CO2 are about 400 ppm. Climate scientists are predicting about 500 ppm of CO2 by mid-century and about 800 ppm to possibly 1,000 ppm by the end of the century. This translates to global temperatures of 8 to 12 digress F higher at century’s end than today if CO2 emissions continue to increase at current rates.
Fundamental 4 – Moisture and Storm Mechanics
Winds come about when there is a differential in temperatures resulting in convection currents. Hot air tends to rise and cool air fall. Temperature differences occur naturally at different elevations due primarily to two mechanisms: 1) ground effect where near ground level it is warmer because the ground gives off heat, and 2) the density of air at ground level is higher and can hold more heat energy whereas at higher elevations the air becomes thinner and is less able to retain heat energy.
However storms need moisture as well which contains much more energy than simply air alone can. Storms are like a huge steam engine. This moisture is largely supplied by ocean water so storms primarily have their origins over oceans. Warmer temperatures result in higher rates of evaporation giving the air mass more energy. Convection winds carry this energy high into the sky where the moisture cools down forming clouds. These clouds grow larger and contain more energy as more moisture accumulates in the rising air. Convection currents together with energy from water vapor cause this moisture to move faster and faster and the rising and falling moisture ladened air creates even stronger storm energy as a progressively larger storm takes form.
The east to west rotation of the earth causes storms in the northern hemisphere to rotate counterclockwise since the equator moves faster than areas closer to the North Pole. These powerful tropical storms originate near the equator where the water is warmest and heavy with moisture then move from north or south. The warmer the water the more moisture evaporates into the air feeding storms with more energy and making them even more powerful. Even a one degree increase in ocean temperature results in enormous volumes of increased evaporation because of the sheer vastness of the oceans covering most of the earth surface. The earth’s rotation moves these huge storm masses containing trillions of tons of swirling moisture from north to south and from east to west. These tropical storms tend to end up on the leading side of continents due to earth’s east to west rotation, as hurricanes on the eastern shores of the Americas in the western hemisphere, and as typhoons on the eastern shores of South East Asia in the eastern hemisphere.
Storms are actually cooler than the normal ambient air temperature due to the clouds that reflects some of the sunlight back into space and shade the air and lands below from the sun’s rays. The high-speed winds causes rain droplets in the storm to evaporate some of their water, feeding their energy back into the storm and cooling the storm further, like a moist rag blown by a fan. This cooler storm mass results in the cool air shrinking in volume as gases do when cooled becoming denser and falling towards the earth creating a kind of vacuum or lower pressures region characteristic of storms. Because of the north to south and east to west motion of storms due to the earths rotation in the northern hemisphere storms rotate counter clockwise in the northern hemisphere and clockwise in the southern hemisphere.
Fundamental 5 – Population and Consumption, the human factor
The root of the problem of excessive greenhouse gases is due to unsustainable human population growth. An estimation of the earth’s population in 1800 was about 1 billion. In 1927 it was 2 billion. In 1974 it was 4 billion. Today it is 7 billion and growing. As our technology advances each person consumes progressively more natural resources and produces progressively more greenhouse gas. The per capita production of greenhouse gases worldwide is roughly proportional to income and affluence. The very poor produce little greenhouse gasses or use products and resources that produce greenhouse gases but are large in population. The affluent conversely produce enormous amounts of greenhouse gases and use products and resources producing enormous amounts of greenhouse gases though their numbers are fewer. The US is responsible for the largest emissions of greenhouse gases globally. China’s greenhouse gas emissions would be much less if the US did not buy or outsource so many products from and to them. So most of the problems are due to our insatiable appetite for things that produce or result in greenhouse gases with an unsustainable population. This population explosion is largely due to modern medical advances that have resulted in lower infant mortality and increase survival and longevity.
Pingback: What is Global Warming (Part 2/3) – The Doomsday Scenario | ouR Social Conscience
Pingback: What YOU Can Do to Make a Difference – Climate Change | ouR Social Conscience
Pingback: What We Can All Do to Help Save Our Planet | Biking Cupertino