Global warming causes droughts * We can stop global warming if we wanted to * Global warming will eventually make the earth uninhabitable * Seasons are getting shorter * The food chain is being disrupted * Quality of life will diminish * Bad for crops and vegetation * Increase health risks * causing more severe weather * reduce the amount of fresh water on the planet * cause a world-wide economic collapse * Mass extinction of species * Sea levels are rising * making our air unsafe * Glaciers are melting at an exceedingly fast rate * The Arctic will dissolve completely in a few centuries * Temperatures is higher than it's ever been

Earth's climate has always been in a state of flux, according to data gleaned from the geological record, ice core samples and other sources. However, since the Industrial Revolution began in the late 1700s, the world's climate has been changing in a rapid and unprecedented way. The average global temperature has risen 1.4 degrees Fahrenheit since 1880, according to NASA. Temperatures are projected to rise another 2 to 11.5 F over the next hundred years, according to the Environmental Protection Agency. Some have confused global warming as persistent, increasing warmth. While the global temperature is increasing, it may not translate to a higher temperature in an individual location. "Global warming is important because it is so persistent and global in scale, and because it brings more extreme events such as heat waves - not because it makes every place warm all the time. It doesn't do that,"said atmospheric scientist Adam Sobel, author of "Storm Surge: Hurricane Sandy, Our Changing Climate, and Extreme Weather of the Past and Future" (HarperWave, 2014). In addition to heat waves, the increase in global temperature is having a massive effect on the environment, such as melting polar ice caps, raising the sea level and fueling dangerous and severe weather patterns. Understanding the causes of global warming is the first step to curbing its effects.

The greenhouse effect

Earth's climate is the result of a balance between the amount of incoming energy from the sun, and energy being radiated out into space.Incoming solar radiation strikes Earth's atmosphere in the form of visible light, plus ultraviolet and infrared radiation, according to NASA's Earth Observatory.Ultraviolet radiation has a higher energy level than visible light, and infrared radiation has a weaker energy level. Some of the sun's incoming radiation is absorbed by the atmosphere, the oceans and the surface of the Earth.Much of it, however, is reflected back out to space as low-energy IR radiation. For Earth's temperature to remain stable, the amount of incoming solar radiation should be roughly equal to the amount of IR radiation leaving the atmosphere. According to NASA satellite measurements, the atmosphere radiates thermal IR energy equivalent to 59 percent of the incoming solar energy.As Earth's atmosphere changes, however, the amount of IR radiation leaving the atmosphere also changes. Since the Industrial Revolution, the burning of fossil fuels such as coal, oil and gasoline have greatly increased the amount of carbon dioxide in the atmosphere, according to NASA's Earth Observatory.Along with other gases like methane and nitrous oxide, CO2 acts like a blanket, absorbing IR radiation and preventing it from leaving the atmosphere. The net effect causes the gradual heating of Earth's atmosphere and surface. [Related: Effects of Global Warming]This is called the "greenhouse effect" because a similar process occurs in a greenhouse: Relatively high-energy UV and visible radiation penetrate the glass> and roof of a greenhouse, but weaker IR radiation isn't able to pass out through the glass. The trapped IR radiation keeps the greenhouse warm, even in the coldest winter weather.

Natural causes vs. human causes

Earth's historic climate changes have included ice ages, warming periods and other fluctuations in climate over many centuries. Some of these historical changes can be attributed to changes in the amount of solar radiation hitting the planet. A drop in solar activity, for example, is believed to have caused the "Little Ice Age," a period of unusually colder climate that lasted from about 1650 to 1850, according to NASA. However, there is no evidence that any increase in solar radiation could be responsible for the steady increase in global temperatures that scientists are now recording, according to the National Oceanic and Atmospheric Administration (NOAA).In other words, natural causes cannot be held responsible for global warming. "There is no scientific debate on this point," the NOAA website states.Indeed, virtually every credible source of scientific research from around the world indicates that human causes, primarily the burning of fossil fuels and the subsequent increase in atmospheric CO2 levels, are responsible for global warming. Some of these organizations are the American Medical Association, Intergovernmental Panel on Climate Change, American Association for the Advancement of Science, Ecological Society of Australia, American Chemical Society, Geological Society of London, American Geophysical Union, International Arctic Science Committee, American Meteorological Society, American Physical Society, and The Geological Society of America. Over 197 international organizations agree on this point."In all honesty, anthropogenic (human-caused) climate change is not a scientific debate, it is a political/economic debate," Werne said. According to Werne, the relevant question is not, "Is there human-induced climate change?" The question that we should be focused on is, if anything, "What should we do about human-induce climate change?"