Investigating Human Influences on Climate
Scientists have been investigating and writing formal research papers on human influences on climate for almost two centuries. There are records of prior observations of this but it was around the 1850s that research on this subject became more codified as a formal subject for research.
While the Earth’s temperatures have risen and fallen to great extremes in its long history only to come back down or up for long periods of moderation, the Earth’s climate is changing rapidly with some alarming results. Many schools of thought point to human activity as being the cause of most of the Earth’s climate change over the past 150 years. Other schools discount humans as being the primary source of climate change compared to other sources of climate change such as, natural disasters, continental drift, the shape of Earth’s orbit around the Sun and extreme weather events.
Prior to human existence and evolution, the Earth’s climate has changed throughout its existence.The Sun is the driving force of climate and Earth’s climate is dependent on it. There have been times, such as what is known as The Ice Age and lesser known glaciation events, when the Earth’s climate change was extreme. While there is no definitive reason for why the Ice Age happened, the one thing for certain is that the Sun’s energy was not reaching Earth. And while there are still different camps of thought for why it happens, it is agreed that the Earth’s overall temperature is on the rise and that climate change is due to the Sun’s energy entering through the atmosphere but not being able to escape away from it.
Greenhouse Gasses and Global Warming
Some point to the 1950s research of the prominent Irish physicist, John Tyndall, as a basis for much of modern research on human influences on climate. He ascribed that when the Sun heats the Earth, the Earth then gives off heat energy as infrared radiation. When greenhouse gases such as water vapor and carbon dioxide absorb the infrared radiation, it heats the atmosphere and surface of the Earth more than if it were only heated by the Sun’s direct light.
The Swedish scientist and one of the founders of the science of physical chemistry, Svante Arrhenius, was the first to use the basic principles of physical chemistry to calculate estimates of the extent to which increases in atmospheric carbon dioxide increase the surface temperature of the Earth. He suggested that people could increase the amount of greenhouse gases in the atmosphere by burning coal. These increases in greenhouse gases from coal emissions, amplify the natural warming affect which results in overall warming of the atmosphere more so than if the coal burning were not present.
In the 1960s, David Keeling used the work of Arrhenius to conclude and demonstrate that carbon dioxide emissions are large enough to cause global warming.
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