TFSAfunds wrote: you decide. Calgary_AB isn't the only one out there questioning the current beliefs regarding "global warming". You hear/see/read the same propoganda often enough, you start to believe it. Some though, aren't taken in quite so easily! 11,000 scientists can't be wrong you say... sure they can, because they lose funding if they "buck the system". Just look at how often hundreds of thousands of Medical Doctors find out they've been "misleading " us, daily aspirin as one example.
Temperature in Perspective
Climatists argue that the Modern Warming, the rise in global temperatures over the last 130 years, is abnormal in Earth’s history. They then conclude that human contribution to a trace gas in our atmosphere, carbon dioxide, must have caused this rise.
But a closer look at temperatures shows that the rise in Earth’s average temperature over the last 130 years has been only about 1.3 degrees Fahrenheit or 0.7 degrees Celsius. In Chicago, temperatures typically swing from about -5°F on the coldest winter day to about 95°F on the hottest summer day, about 100 degrees in a single year. Compared to the annual swing in daily Chicago temperatures, the one degree rise is global temperatures during the Modern Warming has been tiny.
So have past temperatures been constant, as the Climatists claim? Most geologists know that the sites of London, New York, and Chicago, along with much of the Northern Hemisphere, were buried in ice 20,000 years ago during the last ice age. Global temperatures changed as much as 7°-12°C as Earth moved from glacial to interglacial periods in geologic history.
In addition to the ice ages, a vast body of additional evidence shows that Earth’s temperatures are always changing. While the database of modern thermometer measurements only stretches back 130 years, proxy data allows a look at more distant past temperatures. Measurements of oxygen isotope proxies from ice cores in Greenland show periodic warm and cool periods including the Medieval Warm Period and the Little Ice Age, when temperatures were both warmer and cooler than today’s temperatures. Natural climate change is not only real, but continuous.
The Greenhouse Effect
Sunlight, which is high energy radiation, enters our atmosphere and is absorbed by Earth’s surface. Like any warm body, Earth emits radiation. Since Earth’s temperature is lower than that of the sun, Earth emits lower energy radiation called infrared radiation, which is not visible to our eyes. Some of this infrared radiation passes back out of our atmosphere into space, but most is absorbed by greenhouse gases in our atmosphere. The warming caused by this absorption of infrared radiation is called the greenhouse effect.
The greenhouse effect is the theoretical basis for the theory of man-made global warming. Most greenhouse gases in our atmosphere are created by natural climatic processes, so the greenhouse effect is a natural effect. But emission of greenhouse gases from human industry adds to the effect. Climatism warns that man-made greenhouse gases are the cause of rising global surface temperatures and will cause catastrophic climate change. But quantifying the amount of the greenhouse effect contributed by mankind is key to estimating the impact.
Our atmosphere is composed of about 78 percent nitrogen gas, 21 percent oxygen gas, a small amount of water vapor, and other trace gases. Carbon dioxide is a trace gas. Only four molecules in every 10,000 in Earth’s atmosphere are carbon dioxide. The amount of CO2 that mankind may have added in all of human history is only a fraction of one of those four molecules. Yet, Climatists claim that this fraction of one in every 10,000 air molecules is causing catastrophic climate change.
What is nature’s most abundant greenhouse gas? The answer is water vapor! Air typically contains 500 times more water vapor than CO2. Depending upon local humidity, water vapor can form about two percent of the atmosphere, serving as the Earth’s dominant greenhouse gas. Most scientists estimate that water vapor causes between 75 percent and 90 percent of Earth’s greenhouse effect. If we use the conservative number, about 75 percent of the greenhouse effect is due to water vapor and clouds, and of the remaining portion, about 19 percent is due to carbon dioxide, with 6 percent due to methane and other gases. But as indicated by the Carbon Cycle Model of the Intergovernmental Panel on Climate Change (IPCC), only about 3 percent of the CO2 placed into the atmosphere each year is from human emissions. So, of the last 25 percent of the greenhouse effect that is due to carbon dioxide and methane, only about 3 percent of this is due to man-made sources.
This means that man-made emissions are responsible for only about one percent of the greenhouse effect. When we consider the effects of evaporation, convection, and weather, human effects on global warming are even less than this one percent. This small effect is impossible to even detect in Earth’s surface temperatures.