One of the most talked about topics in meteorology and climatology is global warming. Global warming is the theory that states when greenhouse gases are added to the earth's atmosphere the result will be for increased average global temperature. The main greenhouse gas that is of concern is Carbon Dioxide. The replacing of trees and vegetation with pavement also contributes to warmer surface temperatures. This page will clarify many of the issues about global warming. It has been debated whether global warming is a theory or a fact. The overwhelming majority of scientists studying the issue agree that global warming is a fact, although there is considerable debate on the magnitude. Although global warming is widely believed, it is a problem that is easy to put off. It is easier to notice sudden changes such as a volcanic eruptions and tsunamis than it is to notice slow processes such as climate change. At one extreme of the global warming debate is those that believe the change in precipitation, temperature and sea level will be severe. They predict the average global temperature to rise several degrees Celsius over the next several decades. Sea level will rise and take over large portions of the land in coastal areas. Agriculture will be significantly impacted with some currently rainy regions becoming much drier and some dry regions becoming much wetter. Humans will be unable to adapt very successfully to the change: disease, famine and destruction of the world economy will far surpass the problems of today. At the other extreme are those that do not believe in global warming or at least do not believe that humans are impacting the global temperature, precipitation and sea level patterns. They will claim any change is natural and that the human influence is not large enough to have any kind of major impact. They will often mention that nature over time will cleanse the pollution out of the air thus it is okay to continue to add any volume of air pollution. It is likely that human pollution does impact the world climate. The impact is probably not as great as many predict. The addition of large volumes of air pollution every day into the atmosphere must have some result since it is changing the composition of the atmosphere. From 1900 to 2008 the world population has increased about 4 times over. The amount of Carbon Dioxide emitted into the atmosphere has increased dramatically as population and industrialization has increase. This is important since there is a direct relationship between the amount of CO2 (Carbon Dioxide) in the air and temperature. As CO2 goes up, temperature goes up since CO2 traps more energy in the atmosphere that would have otherwise escaped out of the atmosphere. Below is a link to a graph showing the increase of CO2 in the atmosphere over time measured in the middle of the Pacific Ocean. http://en.wikipedia.org/wiki/Image:CO2_data_mlo.svg Notice that the trend since the start of the data in 1957 is a continuous increase of C02 in the atmosphere. The up and down on the graph each year is due to the fact that there is much more vegetation in the Northern Hemisphere. In the Northern Hemisphere summer plants use more CO2 and the value goes down. In winter it goes up due to many plants not using as much CO2. The 380 ppm value at 2006 represents the highest the CO2 value has been in the atmosphere in human history. With the ability to sample ice cores from over the last 650,000 years it was found that the CO2 value today is even higher than it has ever been even with that long time period. The result should be no surprise that the earth is warming up and climates are changing! How can humans cause global warming when the earth is so big? Isn't the human influence like a drop of water in a large bucket of water? This used to be the case but not anymore. Human technology has advanced to the point and is of enough of a magnitude that is can and does influence the earth's atmosphere. The technology is available to remove forests, destroy civilizations through nuclear weapons, transform the land's vegetation, and emit enough pollution into the atmosphere to alter earth's climates. As air pollution increases, the problem increases. As an analogy imagine eating one fatty cheeseburger per month. Then eat 5 per month. Then eat 20 per month. Then eat 40 per month. Then eat 100 per month. As the number of fatty greasy cheeseburgers eaten per month increases, the trend will be for increased health problems. 5 cheeseburgers per month is less likely to harm your health than 100 per month. There is a threshold of cheeseburger eating that when that threshold is passed, health will decline. The same is true for the atmosphere. The amount of pollution emitted into the atmosphere has passed that threshold in which there will be no influence. As pollution emitted into the atmosphere continues to increase, the climate change will only intensify. It will be critical to start reversing this trend. The glaciers and ice caps are melting. Why? The earth is warming up! When looking at how the size of glaciers have changed over the last several decades the trend is for retreating glaciers. For an analysis and examples see the link below: http://en.wikipedia.org/wiki/Retreat_of_glaciers_since_1850 The skeptics will say it is a cyclical phenomena. Glaciers expand and then they retreat in cycles. It just happens to be on a retreating cycle today. There is certainly truth in the cycles. Global warming though will enhance the retreating cycle. The glaciers and ice caps are retreating at a rate that is well beyond what would be expected in a normal retreating cycle. So much ice is retreating that is important for drinking water. Entire glacier systems are disappearing. The North Pole ice cap is thinning. It is the polar areas that will have the most significant influence from global warming when it comes to the temperature increase. This is because as the ice pack decreases, more sunlight is able to absorb into the land and ocean. While ice reflects much of the solar radiation that strikes it, water and land reflect less solar radiation. The impacts of global warming on climate will be significant. As temperature warms, more moisture can be evaporated into the air. Semi-arid areas are becoming deserts because of the temperature increase evaporating away critical moisture that is needed for the land. Dry climates are becoming drier and wet climates are becoming wetter. With more moisture evaporating into the air, where it does rain the rain is more intense. This creates extreme flooding in areas the moisture advects into and rains out. The last couple of decades have seen several of the hottest years on record. Global warming plus local warming are contributors. As places urbanize, they heat up (urban heat island). Temperature sensors in an urbanizing area will warm more than they otherwise would. Add to this global warming and it is no surprise that the hottest years in history have occurred recently. The influences of global warming include: 1. Rising sea level 2. High latitude climates being more hospitable to settlement 3. Flooding over of shallow islands that are currently just above sea level 4. Loss of many species that are adapted to specific climates 5. Increase of diseases that colder weather would normally keep at bay How much of a problem is global warming? Humans are the most adaptable and advanced life to live on earth. I am not worried about humans adapting the global warming. We already have proven we can live successfully in any type of climate. If sea level rises, we will adapt. If the climate gets hotter, wetter or drier in our region we will adapt. Global warming can not and will not wipe out human civilization because of our incredible adaptive powers. Full scale nuclear war or a meteor impact are much more of a threat to ending human civilization. Even with global warming, the world population will keep going up by many more billions in this century. What I do worry about is animal and plant life that is not able to adapt. Incredible numbers of species on earth will die due to the human influence. Human technology and know-how has taken over the planet. Dams, farming, deforestation, urbanization, mining, land management, fencing and irrigation have all transformed the earth. Anything that does not benefit humans is in trouble of surviving or will be confined to zoos, labs and park lands. The most troubling aspect of how human's have treated the earth is pollution. It can't be healthy to breath all the "crap" that is put into the air and it can not be healthy for the environment to absorb all the pollution. This is the primary reason I believe in "going green". Going green involves using more efficient appliances, recycling, using higher mileage vehicles, using less fossil fuels, better disposal of industrial waste products and moving beyond carbon for energy resources. The time has come to build nuclear power plants and safely dispose of waste. Nuclear power is far less polluting when done right compared to fossil fuels. Since an incredible amount of energy is needed to run an industrial economy like the USA, nuclear power offers incredible amounts of energy that is far less polluting. For automobiles, the gas mileage standards need to increase dramatically. The benefits of this is less carbon emitted into the air and to reduce the amount of fossil fuel used to power the vehicle. With gas being so expensive, a high mileage vehicle will lower fuel costs. Go Green! |