Green Myth-Busting: CO2 Emissions
Carbon Dioxide Molecule
Myth: Compared to natural carbon dioxide emissions, manmade emissions are insignificant.
Fact: The argument is occasionally made by global warming skeptics that manmade carbon dioxide emissions are much smaller than natural emissions. Some skeptics will even quote figures in decimal or percent form, which makes it look even more true. If this is the case, according to their logic, our attempts to stop global warming are futile because we can't make a difference. This argument is blatantly false and is based on a complete lack of understanding of our environment.
On our planet, there is an ongoing process called the carbon cycle, in which carbon dioxide is both emitted and absorbed naturally. The absorption part of the cycle is what is missing from this myth. It is true that very large amounts of CO2 are emitted naturally, but there is also a carbon dioxide sink, which is the name for the absorption process. The sink removes slightly more carbon dioxide from the air than is emitted naturally. Therefore, any natural CO2 emissions are a wash.
Carbon Cycle
Actually, the natural sink is also absorbing much of the emissions resulting from human activity. In fact, the only reason any of our emissions end up in the atmosphere is because we're emitting CO2 faster than the planet can absorb it:
The roughly 500 billion metric tons of carbon we have produced is enough to have raised the atmospheric concentration of CO2 to nearly 500 ppm. The concentrations have not reached that level because the ocean and the terrestrial biosphere have the capacity to absorb some of the CO2 we produce. However, it is the fact that we produce CO2 faster than the ocean and biosphere can absorb it that explains the observed increase. - RealClimate
This has resulted in an increase in CO2 concentrations over the last century and a half of about 100 parts per million, from 280 ppm to 380 ppm. Nearly all of this increase has been due to human activity. Another way we know this, besides a simple look at the increase in human activity over the past two centuries, is by measurements of different isotopes of the carbon atom:
Isotopes are simply different atoms with the same chemical behavior (isotope means “same type”) but with different masses. Carbon is composed of three different isotopes, 14C, 13C and 12C. 12C is the most common. 13C is about 1% of the total. 14C accounts for only about 1 in 1 trillion carbon atoms. CO2 produced from burning fossil fuels or burning forests has quite a different isotopic composition from CO2 in the atmosphere. This is because plants have a preference for the lighter isotopes (12C vs. 13C); thus they have lower 13C/12C ratios. Since fossil fuels are ultimately derived from ancient plants, plants and fossil fuels all have roughly the same 13C/12C ratio – about 2% lower than that of the atmosphere. As CO2 from these materials is released into, and mixes with, the atmosphere, the average 13C/12C ratio of the atmosphere decreases. - RealClimate
So, not only are manmade CO2 emissions significant, they actually make up an overwhelming majority of the recent increase in CO2 concentrations in the atmosphere. Looking into the future, manmade CO2 emissions are predicted to continue increasing, which will no doubt result in higher concentrations of the gas in the atmosphere. Therefore, our efforts to cut back on emissions will indeed make a difference for the future of our planet.
Tags: anthropogenic, carbon dioxide, Climate Change, CO2, emissions, Green Myth-Busting, Science and Tech
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December 10th, 2008 at 2:44 pm
Just a small point…c13 ratios in fossil fuels are not all the same.
Coal is the fossilised complete plant but petroleum is the remains of the lipids (oils) from the plants.
Plants differentiate between C12/13 during basic chemistry (the lower the mass the more rapid the reaction so C12 reacts faster than C13) and through enzyme action which preferentially builds lipids from C12. So petroleum fuels contain less C13 than coal.
March 7th, 2009 at 8:36 pm
Well take a look at this
http://www.geocraft.com/WVFossils/greenhouse_data.html
March 7th, 2009 at 9:54 pm
Rich,
I’ve visited that webpage many times before. It’s propaganda and conspiracy.
The author is confusing two very different ideas: the total greenhouse effect and global warming (or a CHANGE in the greenhouse effect). It is true that water vapor is much more abundant in the atmosphere than CO2, and therefore plays a more dominant role in the total greenhouse effect. However, this is a red herring in discussions of climate change. The most important greenhouse gas when it comes to climate CHANGE is carbon dioxide. This is because of one very important factor: atmospheric lifetime. Water vapor has a very short atmospheric lifetime (7 to 10 days, compared to about 250 years for CO2). So, atmospheric concentrations of water vapor fluctuate rapidly in response to changes in temperature, whereas once carbon dioxide is in the atmosphere, it stays there for many decades. This makes water vapor a feedback, because it cannot CAUSE a CHANGE in temperature — it can only amplify the effects of other catalysts, such as CO2. Therefore, water vapor is not considered in discussions about the causes of global warming. Got it?
July 3rd, 2009 at 2:47 pm
The Climate Change Climate Change
“Steve Fielding recently asked the Obama administration to reassure him on the science of man-made global warming. When the administration proved unhelpful, Mr. Fielding decided to vote against climate-change legislation.
If you haven’t heard of this politician, it’s because he’s a member of the Australian Senate. As the U.S. House of Representatives prepares to pass a climate-change bill, the Australian Parliament is preparing to kill its own country’s carbon-emissions scheme. Why? A growing number of Australian politicians, scientists and citizens once again doubt the science of human-caused global warming.
Among the many reasons President Barack Obama and the Democratic majority are so intent on quickly jamming a cap-and-trade system through Congress is because the global warming tide is again shifting. It turns out Al Gore and the United Nations (with an assist from the media), did a little too vociferous a job smearing anyone who disagreed with them as “deniers.” The backlash has brought the scientific debate roaring back to life in Australia, Europe, Japan and even, if less reported, the U.S.
In April, the Polish Academy of Sciences published a document challenging man-made global warming. In the Czech Republic, where President Vaclav Klaus remains a leading skeptic, today only 11% of the population believes humans play a role. In France, President Nicolas Sarkozy wants to tap Claude Allegre to lead the country’s new ministry of industry and innovation. Twenty years ago Mr. Allegre was among the first to trill about man-made global warming, but the geochemist has since recanted. New Zealand last year elected a new government, which immediately suspended the country’s weeks-old cap-and-trade program.
The number of skeptics, far from shrinking, is swelling. Oklahoma Sen. Jim Inhofe now counts more than 700 scientists who disagree with the U.N. — 13 times the number who authored the U.N.’s 2007 climate summary for policymakers. Joanne Simpson, the world’s first woman to receive a Ph.D. in meteorology, expressed relief upon her retirement last year that she was finally free to speak “frankly” of her nonbelief. Dr. Kiminori Itoh, a Japanese environmental physical chemist who contributed to a U.N. climate report, dubs man-made warming “the worst scientific scandal in history.” Norway’s Ivar Giaever, Nobel Prize winner for physics, decries it as the “new religion.” A group of 54 noted physicists, led by Princeton’s Will Happer, is demanding the American Physical Society revise its position that the science is settled. (Both Nature and Science magazines have refused to run the physicists’ open letter.)
The collapse of the “consensus” has been driven by reality. The inconvenient truth is that the earth’s temperatures have flat-lined since 2001, despite growing concentrations of C02. Peer-reviewed research has debunked doomsday scenarios about the polar ice caps, hurricanes, malaria, extinctions, rising oceans. A global financial crisis has politicians taking a harder look at the science that would require them to hamstring their economies to rein in carbon.
Credit for Australia’s own era of renewed enlightenment goes to Dr. Ian Plimer, a well-known Australian geologist. Earlier this year he published “Heaven and Earth,” a damning critique of the “evidence” underpinning man-made global warming. The book is already in its fifth printing. So compelling is it that Paul Sheehan, a noted Australian columnist — and ardent global warming believer — in April humbly pronounced it “an evidence-based attack on conformity and orthodoxy, including my own, and a reminder to respect informed dissent and beware of ideology subverting evidence.” Australian polls have shown a sharp uptick in public skepticism; the press is back to questioning scientific dogma; blogs are having a field day.
The rise in skepticism also came as Prime Minister Kevin Rudd, elected like Mr. Obama on promises to combat global warming, was attempting his own emissions-reduction scheme. His administration was forced to delay the implementation of the program until at least 2011, just to get the legislation through Australia’s House. The Senate was not so easily swayed.
Mr. Fielding, a crucial vote on the bill, was so alarmed by the renewed science debate that he made a fact-finding trip to the U.S., attending the Heartland Institute’s annual conference for climate skeptics. He also visited with Joseph Aldy, Mr. Obama’s special assistant on energy and the environment, where he challenged the Obama team to address his doubts. They apparently didn’t.
This week Mr. Fielding issued a statement: He would not be voting for the bill. He would not risk job losses on “unconvincing green science.” The bill is set to founder as the Australian parliament breaks for the winter.
Republicans in the U.S. have, in recent years, turned ever more to the cost arguments against climate legislation. That’s made sense in light of the economic crisis. If Speaker Nancy Pelosi fails to push through her bill, it will be because rural and Blue Dog Democrats fret about the economic ramifications. Yet if the rest of the world is any indication, now might be the time for U.S. politicians to re-engage on the science. One thing for sure: They won’t be alone.”
http://online.wsj.com/article/SB124597505076157449.html
November 9th, 2009 at 4:59 pm
If earth can’t handle some naughty humans burning fossil fuels, then it’s not such a special place after all.
Fact is though, whether we restrain our carbon appetites or not, nature will remain in control.
The idea of destructive climate change is premised on the idea that positive feedback will make earth uninhabitable. Yet we know that earth’s cycles are regulated by negative feedback. External inputs like an unusually powerful sun or a meteor, can disrupt the system, but we will be hard-pressed to do so all by ourselves.
After all, no other life on earth has managed to make earth uninhabitable, and it’s had 4 billion years to do so by whatever means it may have stumbled across. Quite the contrary, life has turned a noxious atmosphere of methane and carbon dioxide into a highly oxidative one, eventually supporting land mammals so advanced they think they might be undoing all that hard work, just by accident.
November 9th, 2009 at 6:29 pm
Tom,
The fallacy in the argument that the earth has always cycled, and will continue to do so, is that our planet has never faced a threat like that which now exists. Tell me, what means did the single-cell organisms that occupied this planet for the majority of the 4 billion years you mentioned find to make our planet uninhabitable? Never before have we had billions of humans on this planet, living in industrialized societies, in which carbon dioxide is being created in an UNNATURAL process.
Many scientific measurements have shown that recent trends are unprecendented. The current concentration of carbon dioxide in the atmosphere is higher than at any time in the last 650 million years, according to measurements taken from ice cores. In addition, the RATE of warming over the last two centuries has been greater than at any time in recorded history. Combine these with the fact that our CO2 emissions are so great that the natural carbon sinks cannot keep up, and we have a potential for very dire consequences.
So, you can go on believing red herrings and other fallacious arguments, or you can choose to understand and appreciate climate science. The vast majority of research in the field of climate science supports the theory that the planet will continue to warm, unless something is done soon to reduce emissions. Your canard about the planet’s history does nothing to change that.