A new national survey conducted by Pew Research shows that more Americans are growing skeptical of global warming. This, despite the fact that the scientific opinion on climate change remains steadfast in endorsing the position of the IPCC (Intergovernmental Panel on Climate Change), which attributes most of the global warming observed over the last 50 years to human activities.
So what exactly are the human-related factors that cause global warming?
The most impactful global warming causes fall under one general heading: the increasing concentration of greenhouse gases in the atmosphere. This is largely due to emissions brought about by human activity. First, we’ll identify the greenhouse gases, then we’ll pinpoint their most likely sources.
The gases that have been largely identified with the greenhouse effect are: water vapor, which accounts up to 70%, carbon dioxide (up to 26%), then methane and ozone.
It is in carbon dioxide emissions where humans are identified as accomplices to global warming causes. The rise in carbon dioxide emissions can be traced back to the start of the Industrial Revolution in the 18th century.
About 75% of the increase in atmospheric carbon dioxide over the past 20 years is attributed to fossil fuel burning, while much of the remaining percentage is believed to be caused by deforestation (also a man-made activity).
While fossil fuel burning results in emissions of up to 21 billion tonnes of carbon dioxide every year, only half of that can be used up by the environment. As such, the remaining 10.5 billion tonnes are accumulated in the atmosphere, preventing heat from the Sun from leaving.
Some products of fossil fuels are gasoline, diesel and coal. These materials are used in automobiles, coal-powered plants, and other machines. What machine do you know that doesn’t run purely on these materials? Not many, right? The vehicles you ride each day and the electricity you consume in your homes and offices all rely heavily on fossil fuel.
Is it therefor still surprising that carbon dioxide levels are rising?
Not everyone is quick to point an accusing finger to human beings and their activities as major contributors to global warming causes. There are those who believe it (global warming) as a consequence of increased solar output, volcanic activity, and other variables related to the Earth’s orbit around the Sun.
If the question however is, what does the scientific community say? Well, we already know the answer.
Want to see some pictures of global warming? We’ve got them here in Universe Today. Perhaps you’d also want to read the peculiar article: NASA Uses 90 Rubber Ducks to Study Global Warming.
Since we’ve mentioned NASA, here are some global warming related articles from their site.
NASA’s Climate Change page
NASA Study Predicts More Severe Storms With Global Warming
Here are some interesting episodes from Astronomy Cast:
Galileoscope, Black Hole Time, and What Exactly is Energy
Energy Levels and Spectra
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