The Effects of Global Warming
Global warming during the past century has been so gradual as to be nearly imperceptible. Neither does it adhere to a regular schedule or predictable pattern, which perhaps explains why doubters and nay-sayers still dispute the whole idea. Their ranks are shrinking, however, in the face of a growing body of evidence.
Experts now tell us that if we do nothing to reduce the release of heat-trapping gases into the atmosphere, we can expect temperatures to rise during the next century from 2.7 to 8.1 degrees Fahrenheit (1.5 to 4.5 degrees C.). Even these increases seem small and no cause for alarm, particularly here on the coast where ocean breezes usually temper even the hottest days.
The problem, remember, is global warming; the operative word here is global. The increases will be in average temperatures, and even then we’ll still probably experience cool spells, cold snaps, and years that aren’t as hot as we might expect. With rising average temperatures, however, come increases in the probability of warmer days and more of them.
For example, studies indicate that temperate-zone cities now recording maximum temperatures exceeding 90 degrees Fahrenheit 35 days a year will, by the year 2020, swelter under such heat for an additional 50 days a year.
While many of us might think first of the discomfort, inconvenience, and expense we would have to bear as the planet’s climate warms, the greatest effects are likely to be far more catastrophic. They include the dieback of forests; severe drought, possibly leading to crop failures and famine; and a rise in sea levels, which could greatly alter our coastlines, not to mention our lifestyles.
We have already done a great deal of irreversible damage to our atmosphere since preindustrial days. For example, we expect chlorofluorocarbons (CFCs) and related atmospheric greenhouse gases to have doubled by the year 2050. Without dramatic measures to decrease emissions worldwide, the consequences could be dire.
Although developing nations now contribute about 30 percent of the global carbon dioxide released into the atmosphere, scientists estimate that their dense populations and industrialization will increase that amount to more than 50 percent by the year 2025.
We can’t solve these problems overnight. In fact, even if we were able to immediately take the most drastic measures to reduce emissions of greenhouse gases, it would take several decades to check the progress of global warming.
So some continued warming is inevitable. Most scientists agree that one certain result will be a rise in the world’s sea level. In fact, that process is already underway.
What Are the Effects Of Global Warming?
All 10 of the warmest years on record have occurred in the last 15 years.
The 1990s have already been warmer than the 1980s–the warmest decade on record–by almost 0.2.F (0.1.C), according to the Goddard Institute of Space Studies.
In vast areas of the United States, temperature increases in a range of 2.-4.F (1.1.- 2.C) have been measured during this century.
The global average surface temperature has risen 0.5.-1.1.F (0.3.-0.6.C) since reliable records began in the second half of the 19th century.
These are just a few temperature effects facts to start us off with. Here are a few future effects that we will go into more detail about.
E.xpansion of the earth’s deserts
The first effect, human health, is based upon all the other devastating effects. All animals have a limiting factor. The limiting factor, if changed even the slightest, means the end to that particular species in the habitat where the limiting factor has changed. Quite often, the limiting factor is heat. For humans, if we were even an foot closer to the sun, it could mean the end of our race. Although the effects of global Warming will not necessarily kill humans or other species, the change in heat can effect our health in many other ways. For instance, bacteria in heat is more prone to reproduce, so our drinking water could become more contaminated, therefore increasing the risk that we would drink contaminated water. There are many other situations just like that which could arise from global warming.
Another effect is the severe stress on other many different environments, like wetlands, forests etc. With the increased temperature in the atmosphere from global warming, more water will be evaporated into water vapor, an unusable form of water. This would mean less water for animals, vegetation, and all living organisms. With less water, wetlands could dry up, and the species inhabiting the wetlands, with no water to help keep them alive, would become extinct.
The dislocation of agriculture and commerce is very bad for the United States, and very good for places like Russia. When the atmosphere begins to get too hot the soil dries up and is unable to produce the many products the United States exports and sells to its own inhabitants. If this happens, exports would slow way down creating a panic, and all our importees would scramble for the world’s food-importing countries, causing food prices to shoot up. This almost happened in 1988 when the Midwest had a drought due to a lack of rain and increase in heat, and could not produce the corn and wheat they usually do(corn and wheat depend heavily on rain and melting snow). If another drought like that happened again, its very possible the world would panic. But other traditionally colder countries who experienced the increase in temperature would greatly benefit by being able to grow products that normally would not grow in those areas due to a cold temperature. These countries would not be able to make up for the lack of production in the United States, though.
There are a few places on Earth that, with an increase in temperature, would become deserts. This slight change would be devastating to the people inhabiting these places. Although quite hot already, slightly more fertile and wet land would easily lose its very little moisture from an increased atmosphere temperature. The people and animals living in these places depend on the little water they have available, and would either die or have to migrate when the area turned to desert. Global Warming’s effects can claim lives and homes in many different ways.
The melting of polar ice caps and the consequent rise in sea level is one of the most devastating effects global warming could cause. If the polar ice caps melted just one inch, they would flood coastal cities. Since 1990 sea level has risen four to six inches. It is predicted that by the middle of next century the sea could have risen three feet, which would mean the flooding of cities like New York, London, etc. Thousands of people and animals would lose there homes, and the United States, and many other parts of the world, already have overcrowding problems. Many of the United States’ most productive cities are coastal cities. There destruction could begin the demise of our civilization.
As you can see, global warming has many devastating effects, and possibly even more that we cannot conceive of until they actually happen. Read on to see how the world is trying to prevent continuation of global warming!
Global Warming and Climate Change
Global warming refers to an expected rise in global average temperature due to the continued emission of greenhouse gases produced by industry and agriculture which trap heat in the atmosphere. Higher temperatures are expected to be accompanied by changing patterns of precipitation frequency and intensity, changes in soil moisture, and a rise of the global sea level. Greenhouse gases in the atmosphere act like the glass in the greenhouse: they are transparent to sunlight, which warms the Earth, but they prevent some heat from escaping into space, keeping Earth warmer than it otherwise would be. A majority of this greenhouse effect is natural, maintaining Earth’s average temperature at about 60oF (15oC). Without the natural greenhouse effect, Earth’s average temperature would be closer to 0oF (-18oC). The atmospheric concentrations of several greenhouse gases are rising as a result of human activity. Carbon dioxide, the most important human-made greenhouse gas, is released primarily by the burning of fossil fuels like coal, oil, and natural gas. Its concentration has risen by nearly 30% over its value in pre-industrial times. Concentrations of other greenhouse gases have also risen; methane levels have more than doubled and nitrous oxide levels are increasing as well. There is a world-wide consensus among climate scientists that global average temperature will rise over the next 100 years if the release of greenhouse gases from human activity continues to grow. Assessments by the U.S. National Academy of Sciences and the United Nations’ Intergovernmental Panel on Climate Change (IPCC) project that Earth could experience the fastest warming in the history of civilization during the 21st century. Specifically, according to the IPCC, Earth may warm by 1.8oF to 6.3oF by the end of the next century, potentially making it warmer than at any time since the evolution of modern humans. Such a global temperature rise would be associated with significant climate change. The difference in global average temperature between modern times and the last ice age — when much of Canada and the northern United States were covered with a thick ice sheet — was only about 9oF. A temperature rise of similar magnitude could have serious, potentially devastating effects on society and ecosystems. While the pace and magnitude of future climate change are still uncertain, there is widespread agreement among scientists and government officials on the key aspects of global warming. This consensus led to negotiation and signing of the United Nations Framework Convention on Climate Change at the 1992 Earth Summit held at Rio de Janiero. The treaty embodied a voluntary commitment by industrial countries to return their emissions to 1990 levels by year 2000. The treaty was strengthened in 1997 by addition of the Kyoto Protocol which calls for mandatory reductions of emissions by industrial countries (e.g., 7% below 1990 levels for the U.S. based on average emissions for the period 2008-2012).
The burning of fossil fuels such as oil, coal and natural gas by cars, trucks, power plants and factories along with deforestation, agriculture and other human activities have contributed to a significant increase in the concentrations of greenhouse gases in the atmosphere. Most climate scientists agree that increased concentrations of greenhouse gases from human activities are probably already contributing to global climate change, and their sophisticated computer models are constantly improving estimates of how much and how fast our climate will change in the future. Using the latest data, the Intergovernmental Panel on Climate Change (IPCC), an international group of over 2,000 scientists, projects a global average warming of from 1.8 to 6.3.F (1 to 3.5.C) with a “best estimate” of 3.6.F (2.C) by the year 2100.
But what does this mean to YOU — in your region, state, city and neighborhood? At first glance, this amount of warming might seem trivial. Temperatures fluctuate more than this in a single day, let alone in the course of a year. However, in climatic terms, such a rise is highly significant. For example, during the last ice age, the Earth was only about 9.F (5.C) cooler, on average, than it is today. Moreover, average global warming of greater than 1.8.F (1.C) in a century has not occurred in the last 10,000 years. It’s quite likely that the projected warming will bring significant changes in YOUR weather.
Hot Town, Summer in the City
This analysis illustrates one potential impact of global warming: the projected increase in the number of hot days, for 34 selected U.S. cities. Using historical weather data, we established a baseline of the average number of days in a year each city exceeds 90., 95. and 100.F. To this baseline we added three scenarios of climate change: average warming of 1.8.F (1.C), 3.6.F(2.C) and 5.4.F(3.C) [based on the IPCC synthesis, these correspond to low, medium, and high scenarios -- with the medium scenario considered IPCC's "best estimate" -- for the year 2100]. We then ranked the cities by their increase in number of days over 90.F compared to current levels using the medium warming scenario (plus 3.6.F).
It is important to remember that these estimates represent “average” climatic conditions. Some summers may be warmer and others colder than this average. This summer’s heat wave in much of the country is well above average in relation to current climate. If emissions of greenhouse gases are not brought under control, the average number of very hot days in a summer would increase dramatically. That means that weather like this summer’s would no longer mean record high temperatures. In the year 2100, weather like this summer’s would be considered normal.
About the Analysis
The climate analysis was prepared by Dr. Cynthia Rosenzweig and Richard Goldberg at the NASA/Goddard Institute for Space Studies (GISS) and Columbia University Center for Climate Systems Research based on sensitivity tests over a range of step-changes in annual average temperature. Historical weather observation data were obtained from Dr. Roy Jenne at the National Center For Atmospheric Research (NCAR), Boulder CO. The periods of historical weather data used vary and are noted for each city. Cities whose historical weather data are more recent (e.g., 1979 to 1997) may generate a warmer current climate than those with less recent historical weather data (e.g., 1951 to 1980) because of warmer temperatures in the 1980’s and 1990’s.
Predictions of climate change are made using computer models that mathematically simulate the Earth’s land, oceans and atmosphere which together determine the Earth’s climate. While most models project global average warming in the range of 1.8 to 6.3.F (1 to 3.5.C) by the year 2100, considerable uncertainty arises when predicting exact temperature dynamics for specific locations in particular years in the future. Therefore this analysis should be viewed as an illustration of what impact global average temperature increases could have on the selected cities, not as an exact prediction of actual weather conditions for these cities in any specific year.
Warming Projections: Miami, Florida
Current Average Number of 90.F, 95.F, and 100.F Days Per Year Compared to Year 2100 Projections
The graph above and the table below illustrate the potential increase in the number of very hot days per year that would occur as a result of global warming by the year 2100. Three scenarios of climate change: low, plus 1.8.F (1.C); medium, plus 3.6.F (2.C), and high, plus 5.4.F (3.C) were added to a current average derived from historical weather data for the years 1951 to 1980. The medium scenario corresponds to the Intergovernmental Panel on Climate Change’s ‘best estimate’ for the year 2100.
Current Average Days Above 90.F Days Above 95.F Days Above 100.F
23 1 0
Warming Scenario for 2100 Days Above 90.F Days Above 95.F Days Above 100.F
Low Increase: + 1.8.F (1.C) 67 2 0
Medium Increase: + 3.6.F (2.C) 121 12 0
High Increase: + 5.4.F (3.C) 164 43 1