Mt. Pinatubo: This aerial view shows the crater formed by the catastrophic eruption on the Philippine island of Luzon on June 15, 1991. Some 900 died, with 42,000 homes destroyed. (Newscom/FILE)
Which is the bigger polluter – humans or volcanoes?
EarthTalk: If you said ‘volcanoes,’ guess again. Here’s why.
By The editors of E Magazine | February 6, 2009 edition
Q: Could it really be true that a single large volcanic eruption launches more greenhouse gases into the atmosphere than the amount generated by all of humanity over history?
– Steve Schlemmer, London
A: The argument that human-caused carbon emissions are merely a drop in the bucket compared with greenhouse gases generated by volcanoes has been making its way around the rumor mill for years. And while it may sound plausible, the science just doesn’t add up.
According to the US Geological Survey, all the world’s volcanoes – on land and undersea – generate about 200 million tons of carbon dioxide (CO2) annually, while our automotive and industrial activities create some 24 billion tons of CO2 emissions every year worldwide. Those facts speak for themselves: Greenhouse gas emissions from volcanoes are less than 1 percent of those generated by today’s human endeavors.
Another indication that human emissions dwarf those of volcanoes is the fact that atmospheric CO2 levels, as measured by sampling stations around the world set up by the federally funded Carbon Dioxide Information Analysis Center, have gone up consistently year after year regardless of whether or not there were major volcanic eruptions in specific years.
“If it were true that individual volcanic eruptions dominated human emissions and were causing the rise in carbon dioxide concentrations, then these carbon dioxide records would be full of spikes – one for each eruption,” says Coby Beck, a journalist writing for the online environmental news portal Grist.org. “Instead, such records show a smooth and regular trend.”
Furthermore, some scientists believe that spectacular volcanic eruptions, like that of Mt. St. Helens in Washington State in 1980 and Mt. Pinatubo in the Philippines in 1991, actually lead to short-term global cooling, not warming. Here’s why: Sulfur dioxide (SO2), ash, and other fine particles ejected high into the stratosphere by an eruption reflect some solar energy back into space instead of letting it into Earth’s atmosphere. SO2, which converts to sulfuric acid aerosol when it hits the stratosphere, can linger there for as long as seven years, and can exercise a cooling effect long after a volcanic eruption has taken place.
Scientists tracking the effects of the major 1991 eruption of the Philippines’ Mt. Pinatubo on the main island of Luzon found that the overall effect of the blast was to cool the surface of the Earth globally by some 0.5 degrees Celsius one year later, even though rising human greenhouse gas emissions and an El Niño event (a warm water current that periodically flows along the coast of Ecuador and Peru in South America) caused some surface warming during the 1991-93 study period.
In an interesting twist on the issue, British researchers last year published an article in the peer-reviewed scientific journal Nature showing how volcanic activity may be contributing to the melting of ice caps in Antarctica – but not because of any emissions, natural or human-caused, per se.
Scientists Hugh Corr and David Vaughan of the British Antarctic Survey believe that volcanoes underneath Antarctica may be melting the continent’s ice sheets from below, just as warming air temperatures from human-induced emissions erode them from above.
Got an environmental question? Write: EarthTalk, c/o E – The Environmental Magazine, Box 5098, Westport, CT 06881. Or e-mail: earthtalk@emagazine.com.
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Comments
2. Arlene Hobbs | 02.07.09
Regarding global warming
I saw a news item on the web about global warming last year. I think the article was in your newspaper.
The news was that Argentina and Brazil were building a dam on the Amazon River to get more electricity to both countrys. The dam would back up the water on the Amazon River and flood the rain forest behind the dam.
The article said that historically, the rain forest supplied 24 percent of the world’s oxygen that was previously in earth’s atmosphere.
Flooding the rain forest would stop the production of oxygen in the rain forest.
Also, I conclude: the rain forest would stop producing 24 percent of the Oxygen in earth’s atmosphere. And it would greatly increase the amount of Carobn Dioxide in earths air! This seems devastating to me!
3. Millard | 02.08.09
Yes, humans create C02 every time they…exhale. Plants inhale C02, and thrive on higher numbers. The idea that it’s a pollutant is absurd. The idea that it’s causing global warming when we have people trapped by ice floes on Lake Erie, is idiotic — and don’t pull the sleight of hand of calling it “climate change” now that things are getting colder. You promised heat, the end of snow, and melting ice caps. “Climage Change” is called “weather.” It’s been around for some time. Perhaps you’ve heard of it?
4. John | 02.08.09
The U.S. Geological Survey has a lot of global warming advocates in it. Although volcanoes might not emit much, the ocean air transfer of Co2 is greater than human emmisions
5. Uthor | 02.10.09
So what you’re saying is that if we start pumping sulfur dioxide into the air, we’ll be good? Awesome!
6. Jeff | 02.10.09
Mike, Please be more even-handed in your comments. Attacking a person does not change the data. Citing two people does not change the data. Please read the four IPCC reports, peer-reviewed and commented, assembled and edited by thousands of scientists in various fields related to global warming.
7. YaGottaBeKiddingMe | 02.10.09
I question the “200 million tons of CO2″ referenced in this slightly one-side article. Those figures are based on estimates of ejected gas and magma from the small number of active, erupting volcanoes being monitored. It does not take into account the amount of CO2 and SO2 emitted from hot spots, calderas, and underwater volcanic activity where these gases find their way into the atmosphere either directly or from the ocean. Scientist have only recently discovered the large active volcanic areas off Australia and under Antarctica so to claim the ants crawling around this 4+ billion year old rock know everything or are to blame is extremely premature.
8. Jeff | 02.10.09
The USGS is pretty thorough. (Did you review it?) The data are from ALL volcanic sources, terrestrial and marine. You claim otherwise. Where are you data? Do you have any?
And the USGS is staffed with scientists, not people who have a leaning. There is a rigorous peer-review process.
Let’s talk about the data.
9. YaGottaBeKiddingMe | 02.10.09
Not ‘dissing’ the USGS. However, using one reference from one of USGS’s own reports on the Long Valley caldera they indicate an average of 110 m/tons of CO2 a day; nearly 50 thousand tons a year from one little spot on the planet. If you have links to this 200 million data I’d love to review it. If they’re right, they’re right, but I question the word ALL when it is a US based agency even though a far reaching one. What are the levels of SO2 introduced into the air annually? What are the levels of methane released annually? We know that Methane has a greater warming effect on the planet than CO2 but scientist still have not determined why oceans emit so much even though it has to pass through an very oxygen rich environment to vent. All I’m saying is there is more to the story than increase CO2 levels. The planet lives and breaths just like everything else and everything is interconnected. Forty years ago plant tectonics was laughable. A year ago the thought of finding hundreds of entirely new species of animals would have seem unrealistic. Imagine what we’ll know tomorrow.
10. Pata | 02.11.09
I wonder whether reading these comments “debunking” the warnings of scientific consensus is like being stoned to death with popcorn.
A factoid here, a misunderstood data point there, a misreading of carefully peer reviewed analysis, … and just plain fudging by fossil fuel paid guff-writers, … we need to stop fearing the hurts of truth and get on with delivering the lifestyle we enjoy by modern, renewable, sustainable means. We can move forward into 20th century technology.
The fossil fuel industry has literally billions of dollars to spend burying people’s heads in the sand. We can’t let them keep doing it.
11. mike from atl | 02.14.09
Pata and Jeff- Here’s a site for you to check out if interested. http://www.oism.org/pproject/pproject.htm#41 Please see the letter from Frederick Seitz, former President of National Academy of Sciences, along with a 12 page academic, peer reviewed article, and a petition signed by over 30,000 scientists. The article is a challenging read but important. When I read it, it really challenged what I thought I knew about global warming theory and helped me separate media images from logic. There are lots of good reasons for converting to renewable energy…and we should continue to do so…it’s also important that we do it for the right reasons or our actions could have costly unintended consequences.
12. Robin | 02.16.09
As we get more data, the models get better. Here are some of the most recent updates to our climate knowledge:
http://www.washingtonpost.com/wp-dyn/content/article/2009/02/14/AR2009021401757.html
http://www.guardian.co.uk/environment/2009/feb/16/chris-field-wildfires-tropical-forests
(btw, climate is not weather. Climate is the average temperature over the entire planet for a year. Weather is different. It’s the highly variable, local fluctuations that occur over much shorter time scales. Colloquial usage doesn’t make this distinction, but climate science does. That can be confusing for people who aren’t themselves climate scientists.)
13. Kevin Pierce | 03.03.09
We know the earth will survive high levels of CO2 in the atmosphere and a warmer climate. It’s happened before and we have very good records of what it was like. Regardless of how a warming trend occurs, it will have significant impact on human populations, especially the very high number of us living within 10 miles of a coast. Humans will also survive. But we may be very uncomfortable.
The question to ask is, “what are the risk factors?” and “what can we hope to influence?” Major simultaneous eruptions from all volcanic sources would be something to pay attention to, but we can’t influence the chance it will happen.
All emissions represent waste. Reducing waste can save money and other useful things like time and lives. CO2 is a wasteful emission. (One could even argue that the CO2 we exhale is a waste). Dow Chemical, not known as a greenie, has been saving big money by reducing CO2 emissions.
If reducing CO2 is a good idea regardless of your faith in science or politics and the risk of being wrong is significant, why are you arguing?
14. Phil | 04.07.09
Mike from Atl; this “paper” has been debunked by legitimate scientists all over. I fear you have never seen a real, actual scientific paper if you accept this as good work. This paper has been sent from the source (an interesting sideline in itself) to many of my colleagues for a chance to sign the petition. Well, none of my peers have anything to do with climate, speciation, or any other temperature affected field. Most of the 30,000 “scientists” this paper claims to have signed on are simply random people who were sent this paper from various mailing lists. Please, please find some legitimate sources.
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1. mike from atl | 02.06.09
Please be a little more even sided in your coverage of this issue. There is no consensus regarding human caused global warming. Warming,anthropogenic, no. CO2 offers the gift of life, increasing plant life, which sustains animal life. Our policymakers are relying on models which are notoriously unreliable and open to agenda driven manipulation. Can we predict next week’s weather? No. Why should we be able to predict climate 100 years from now? If interested in the other side of this debate, please google the Weather Channel founder who calls human caused global warming a harmful myth; also google the former president of the National Academy of Sciences who does not believe in the science. Also, google Al Gore’s undergraduate degrees (hint: it’s not science). Thank you and have a nice evening.