Some myths just won't seem to die. I am referring to the myth that volcanoes have put out far more carbon dioxide into our atmosphere than all that caused by human activity [“‘Emergency’ is paranoia,” March 15].
This claim is credited to the geologist Ian Plimer, whose widely discredited book, Heaven and Earth, claims that humans have had no significant effect on global warming.
Human activity (deforestation and burning of fossil fuels, et cetera) has contributed more than 60 times the amount of carbon dioxide annually compared to that from volcanic emissions.
Data concerning the amounts of carbon dioxide in the atmosphere over the past centuries has been obtained from ice-core samples taken from glaciers in Greenland and Antarctica. These ice-core samples have properties similar to tree rings because of the annual delineation caused by the thawing and freezing process. Scientists can extract the air deposited from many years ago and determine the carbon dioxide content of the air in that core and also know the age of that core sample.
According to the Global Carbon Project, more than 2,000 billion metric tons of carbon dioxide has been added to our atmosphere since the Industrial Revolution. This has, in effect, doubled our original amount of carbon dioxide.
Carbon dioxide is a very necessary gas in our atmosphere. Without it, earth's temperatures would hover around the freezing mark. Understandably the more we add, the hotter our planet becomes because of its greenhouse effect.
Prior to the Industrial Revolution, we were adding less than one billion metric tons per year. At present we are adding more than 40 billion metric tons annually with a record high of over 45 billion in 2015.
Our planet has remained temperate over the years because of two things, our vast oceans and our polar ice caps. Melting of these glaciers will adversely affect our climate.
The federally funded Carbon Dioxide Analysis Center and the Global Carbon Project are two of my sources for statistical data involving climate change.