Global warming is the gradual rise of the earth's surface temperature. The Earth's average temperature has increased by about 1°F (0.5°C) over the past century. An increase in global warming has occurred in the distant past as the result of natural influences, but the term is most often used to refer to the warming predicted to occur as a result of increased emissions of greenhouse gases.
Human and industrial behavior alters the chemical composition of the atmosphere. This occurs through the buildup of greenhouse gases, namely carbon dioxide, methane, nitrous oxide and chlorofluorocarbons. The most probable consequence of these greenhouse gases are increases in temperature, and changes in precipitation, soil moisture and sea level. Economic resources and quality of life such as agriculture, forestry and fishing may be affected.
The main reason that global warming is now being called "Global Climate Change" is because the expected outcome of this world-wide temperature shift is that there will be greater variability and less predictability in regional and local climate. It does not necessarily indicate that temperatures will be warmer at a particular location. Weather patterns can be very complex.
Global Climate Change isn't really a new phenomenon. Historically, Earth’s global temperatures have always fluctuated. These climate changes occurred naturally and took place over hundreds or thousands of years. Consider the hot and humid climate of the Dinosaurs and the frigid climate of the Mastodons.
The difference now is that human activities are rapidly adding to the naturally occurring greenhouse gases in the atmosphere. The natural cycle has been accelerated and the fear is that the "evolutionary cycle" will not be able to adapt to such a rapid change. Trees "migrate" to warmer or colder climate zones over hundreds or even thousands of years while coral reefs - extremely sensitive to temperature changes - take thousands of years to mature. A radical shift in temperature could cause a calamitous loss of habitat.
But how could human activity actually alter the planet's climate? It seems that something as enormous as our planet would be too "big" for us to really interfere with, right? The answer lies in those global warming gases. Carbon Dioxide, the primary global warming gas, only constitutes 0.03% of our atmosphere - essentially a trace gas! Since such a tiny percentage of our atmosphere plays such a crucial roll in our climate, it becomes clearer that "small" changes can make a big difference.
Since the Industrial Revolution, humans have pumped billions of tons of global warming gases into the atmosphere through the burning fossil fuels like coal, oil and natural gas. These fuels have become the backbone of our modern society - they power our cars, homes, and factories. Additionally, landfills produce methane from the decomposition of trash, and intensive agriculture and the livestock that keep us fed also emit huge quantities of Methane - a more potent, yet less abundant greenhouse gas.
Visit the Miami-Dade County Climate Change Advisory Task Force site.
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