by John Brian Shannon
Following an upward trend that began with the Industrial Revolution, the parts per million (ppm) concentration of carbon dioxide (CO2) in the Earth’s atmosphere has soared from an average of 278 ppm in 1760, to an average of 400ppm in 2013 — while the average global temperature has seen a corresponding temperature increase of 2 degrees Celsius during that timeframe.
Prior to the year 1760, CO2 levels moved from 185ppm to 278ppm over a 3 million year timespan – while the average global temperature saw a corresponding temperature increase of 3 degrees Celsius during that timeframe.
From studying air bubbles trapped in Antarctic ice, scientists know that going back 800,000 years, the carbon dioxide level oscillated in a tight band, from about 180 parts per million in the depths of ice ages to about 280 during the warm periods between. The evidence shows that global temperatures and CO2 levels are tightly linked.
For the entire period of human civilization, roughly 8,000 years, the carbon dioxide level was relatively stable near that upper bound. But the burning of fossil fuels has caused a 41 percent increase in the heat-trapping gas since the Industrial Revolution, a mere geological instant, and scientists say the climate is beginning to react, though they expect far larger changes in the future. – Justin Gillis, New York Times, Environment reporter
Human activity (primarily burning of fossil fuels and large-scale livestock and agriculture production) has changed our planetary climate. Almost as much change has occurred over the past 253 years, as occurred over the previous 3 million years!
“It symbolizes that so far we have failed miserably in tackling this problem.” — Pieter P. Tans, Program Monitoring Administrator, National Oceanic and Atmospheric Administration
“It means we are quickly losing the possibility of keeping the climate below what people thought were tolerable thresholds.” — Ralph Keeling, Scripps Institution of Oceanography in San Diego
Here is a nice infographic from Climate Central
Did I mention that sea levels were 20 metres higher (66 feet) than they are nowadays, due to the completely-melted icecaps?
As global warming accelerates, most of the world’s cities could be under water before the end of the century, as many of them are already at or near, sea level now.
Did I mention that the CO2 we are putting into the air will stay in the atmosphere for up to 100 years and it will continue to help increase the global temperature the entire time?
The CO2 that was put into the air in 1960, could still be around for up to another 47 years. Almost without exception, every new year we put more of it into the atmosphere than the year before.
Last year, 2012, we put 36 billion tons (36 Gigatons) of man-made CO2 into the atmosphere — and the Earth systems were only able to absorb half of that. This basic ratio has been occurring for many years now. In 2013, we will add more than 37 Gigatons of greenhouse gases to the air-mass that surrounds the Earth.
What is even worse, and is not being discussed in all of this, is that Oxygen, the one gas that is absolutely necessary for all animal life on the planet, is slowly being replaced by CO2. Oxygen is consumed when fossil fuels, or almost any fuel combusts (burns), and CO2 is what is left over after the Oxygen is consumed.
Professor Ian Plimer of Adelaide University and Professor Jon Harrison of the University of Arizona concur. Like most other scientists they accept that oxygen levels in the atmosphere in prehistoric times averaged around 30% to 35%, compared to only 21% today – and that the levels are even less in densely populated, polluted city centres and industrial complexes, perhaps only 15 % or lower. – Peter Tatchell, “The oxygen crisis” Could the decline of oxygen in the atmosphere undermine our health and threaten human survival?” The Guardian
In humans, failure of oxygen energy metabolism is the single most important risk factor for chronic diseases including cancer and death. ‘Oxygen deficiency’ is currently set at 19.5 percent in enclosed spaces for health and safety , below that, fainting and death may result. – Institute of Science in Society (ISIS) Living with Oxygen (SiS 43)
Not only are CO2 levels rising dramatically and warming the planet — potentially flooding huge rural areas and cities before the end of the century, but Oxygen levels worldwide are falling.
Our civilization is at a critical juncture.
Are we up to the task of making the right decisions, or will we take a pass — thereby forcing our grandchildren to wear oxygen masks every time they leave our airlocked houses to walk to their airlocked school, while we work in office buildings with airlocks and drive cars with oxygen bottles in the passenger compartment, to boost-up the breathable oxygen inside the car, so we don’t fall asleep from breathing higher levels of CO2 and lower levels of life-sustaining oxygen? This scenario is no longer science fiction, but an eventual reality if we don’t change course.
To our credit, we now realize that excessive atmospheric greenhouse gas levels equates to and is directly-linked to excessive consumption of oxygen caused by fossil fuel use and other combustible materials being burned, and we know that CO2 stays in the atmosphere for up to 100 years.
All of which means that much sooner than we may realize, some very serious choices must be made regarding our future fossil fuel burning and combustion-based civilization.
- Global CO2: highest levels in 3 million years (arabiangazette.com)
- Carbon Dioxide milestone: full day at 400 ppm (wtvr.com)
- Climate hits 400ppm of CO2 for first time in 3 million years (treehugger.com)
- Carbon dioxide in atmosphere at highest level for 5 million years (independent.co.uk)
- 400 ppm: Carbon dioxide in the atmosphere reaches prehistoric levels. (blogs.scientificamerican.com)
- 400 ppm …. yikes! (skeptical-science.com)
- 400 (slate.com)
- As carbon dioxide hits a new high, there’s still no Planet B (theconversation.com)
- World in ‘new danger zone’: UN on CO2 record (dailystar.com.lb)
- Carbon Dioxide Passes 400 PPM Milestone, NOAA Finds (climatecentral.org)
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