Stories tagged carbon dioxide

May
07
2012

Carbon dioxide, you light up my life. Or you could, anyway, if this weirdo has his way. Said weirdo is biochemist Pierre Calleja, who has developed a light that can run on carbon dioxide rather than electricity. His secret: green algae that produce energy when they consume CO2.

The mucklight powerhouse: Gross.
The mucklight powerhouse: Gross.Courtesy Jim Conrad

One large lamp he installed in a parking garage consumes up to one ton of CO2 per year. While that's just a drop in the air--the US alone emits almost 5.5 thousand metric tons per year--just think how much these lamps could consume if we replaced all the streetlamps, parking ramp lights, and other environmental lamps with them. It sounds like a pretty great idea when you consider that CO2 is a major driver of global-scale changes in our climate. Whoda thunk we could tackle our warming climate by turning on the lights?

May
02
2012

Cumulative impact by humans on the ocean
Cumulative impact by humans on the oceanCourtesy National Center for Ecological Analysis and Synthesis
One of the great extinctions in Earth history occurred 252 million years ago when about 95 percent of all marine species went extinct. The cause or causes of the Great Dying have long been a subject of much scientific interest.

Now careful analyses of fossils by scientists at Stanford and the University of California, Santa Crux offer evidence that marine animals throughout the ocean died from a combination of factors – a lack of dissolved oxygen, increased ocean acidity and higher water temperatures. What happened to so dramatically stress marine life everywhere?

Geochemical and fossil evidence points to a dramatic rise in the concentration of carbon dioxide in the atmosphere, which in caused a rapid warming of the planet and resulted in large amounts of carbon dioxide dissolving into the ocean and reacting with water to produce carbonic acid, increasing ocean acidity. The top candidate for all this carbon dioxide? – huge volcanic eruptions over thousands of years in what is now northern Russia.

Why should the Great Dying be of more than just academic interest? Humans currently release far more carbon dioxide into the atmosphere than volcanoes and we are releasing carbon dioxide into the atmosphere at a rate that greatly exceeds that believed to have occurred 252 million years ago. The future of Earth’s oceans will be determined by human decision making, either by default or by design. What do we want our future ocean to be?

Apr
10
2012

Atmospheric carbon dioxide concentration during the past 417,000 years
Atmospheric carbon dioxide concentration during the past 417,000 yearsCourtesy Wikipedia Commons
Skeptics of human-induced climate change have long pointed to a lag between an increase in temperature and a rise in atmospheric carbon dioxide at the end of the last Ice Age as suggesting that carbon dioxide is an effect of rising temperatures, not a cause. This lag, however, was based on evidence from only one place on Earth - ice core records from Antarctica.

A much more extensive study of paleo-temperature records from 80 sites around the world just published in Nature reveals that global temperature increases followed rises in the carbon dioxide concentration in the atmosphere. Carbon dioxide is a heat-trapping gas that can drive climate change. This study greatly substantiates climate scientists who point out that the enormous quantities of carbon dioxide that human activities are putting into the atmosphere will result in dramatic changes in global climate if they are not curtailed.

The idea of a synthetic tree to capture excess carbon dioxide from the air was announced in 2003. After years of work, physicist Klaus Lackner will present a public demonstration of the technology today (October 26, 2011) at the London headquarters of the Institution of Mechanical Engineers. Artistic Representation of a Synthetic "Tree Farm"
Artistic Representation of a Synthetic "Tree Farm"Courtesy Institution of Mechanical Engineers

The prototype tree, which looks like a goal post with Venetian blinds, draws carbon dioxide (CO2) out of the air like a plant, but unlike a plant, retains the carbon and does not release oxygen.

Klaus Lackner estimates that some 250,000 such trees, which potentially could be planted anywhere*, even in desert regions, would be needed to soak up the CO2 produced by human activity annually.

Live Webinar at 12:00pm Central Daylight Time, October 26, 2011 (duration 3 hours): Artificial Trees: Giving us the time to act?
Columbia University blogpsot: Artificial Trees: Giving Us Time to Act?



* Well, not anywhere, as I later found out from the Environment 360 blog; the tecnology won't work in cold boreal regions or the humid tropics. And regarding the use of organic trees for carbon capture, see Chapter 31 of David McKay's Sustainable Energy - Without the Hot Air.

Mar
07
2011

You probably know that plants "inhale" carbon dioxide and "exhale" oxygen, but did you know that plants also release water into the air when they exhale? This process is called transpiration, and it plays an important part in our planet's water cycle. I mean, just think of all the billions of plants out there, all of them transpiring 24/7--that really adds up.

Unfortunately, increasing carbon dioxide in the atmosphere has yet another impact on our ecosystems--it reduces transpiration. You see, plants have these tiny pores on the undersides of their leaves called stomata. The stomata open and close depending on the amount of carbon dioxide available in the air and how much they need of it.

It's kind of like your eye's iris--your eye needs an ideal amount of light to see, so when it's bright outside, the iris closes in. This shrinks the pupil so that it only takes in a small amount of light. In lower light, the iris opens, making the pupil larger so that it takes in more light. Like your iris, the stomata open and close to let in the right amount of carbon dioxide.

Stomata: These stomata are from an Arabidopsis plant. The top one is open, and the lower one is closed.
Stomata: These stomata are from an Arabidopsis plant. The top one is open, and the lower one is closed.Courtesy KuriPop

Unfortunately, a recent study showed that with carbon dioxide concentrations increasing quickly, plant stomata are closed longer than they were 150 years ago. There are also simply fewer stomata in leaves. While this controls the amount of carbon dioxide they're absorbing, it has the added outcome of limiting the amount of water released into the air from plants. Over time, this could add up to some significant change--but it's a little early to tell for sure what the impacts will be.

It's kind of amazing to see how changes in carbon dioxide emissions have such far-reaching impacts beyond the one we hear about every day--global warming. Luckily, we have plenty of ways to work on global warming and curtail carbon dioxide emissions, such as cement that absorbs carbon dioxide as it hardens, castles that scrub CO2 from the air, and solar power concentrators that generate 1500 times as much energy as regular solar cells, reducing our dependence on fossil fuels.

What's your favorite way to ditch carbon dioxide?

Oct
25
2010

Have you ever heard of ‘ocean acidification’? If not, don’t feel alone. You are in vast majority. A new study by Dr. Anthony Leiserowitz at Yale University found that that just 25 percent of Americans have ever heard of ocean acidification – the process whereby carbon dioxide released into the atmosphere by human activities eventually dissolves into the sea producing carbonic acid which depresses the pH of the ocean. Ocean acidification threatens to dramatically alter marine life if present trends continue. A more informed citizenry is essential if steps are to be taken to address this threat to our futures.

The Science Museum of Minnesota and Fresh Energy on the evening of Thursday, November 4 are hosting the Twin Cities film premiere of the documentary, A Sea Change . The screening of this award-winning, 90-minute film will begin at 6:30 PM followed by Q&A with the film’s director, co-producer, lead NOAA ocean acidification scientist, and Fresh Energy’s science policy director and then concluding with a dessert reception. I hope that you will take advantage of this unique opportunity to see the film and then socialize afterwards. Go to the Science Museum's adult programs to order your tickets.

Oct
07
2010

What if I told you University of Minnesota geology and geophysics professor, Martin Saar, says geothermal energy can be made even greener through carbon sequestration?!

You’d probably say, “Huh?? Hold on, what is geothermal energy anyway, and how does it work?”

Geothermal is heat from deep inside the earth. Because heat is a form of energy, it can be captured and used to heat buildings or make electricity. There are three basic ways geothermal power plants work:

  1. Dry steam plants: Uses high-pressured hot steam to turn generator turbines. Think “steam to turbines.”
  2. Flash steam plants: Uses high-pressure hot water to create steam to turn generator turbines. Think “water to steam to turbines.”
  3. Binary cycle power plants: Uses high-pressure hot water to heat another liquid, which then turns to steam and turns the generator turbines. Think “water to other liquid to steam to turbines.”

(Click here for great diagrams of each of these geothermal energy production methods.)

“And what about carbon sequestration too? What’s that and how does it work?”
Carbon Sequestration: This nifty diagram illustrates both terrestrial and geologic carbon sequestration pathways.  Bonus!
Carbon Sequestration: This nifty diagram illustrates both terrestrial and geologic carbon sequestration pathways. Bonus!Courtesy Department of Energy

Carbon sequestration includes carbon (usually in the form of carbon dioxide, CO2) capture, separation, transportation, and storage or reuse. Plants, which “breathe” CO2, naturally sequester carbon, but people have found ways to do it artificially too. When fossil fuels are burned to power your car or heat your home, they emit CO2, a greenhouse gas partially responsible for global climate change. It is possible to capture those emissions, separate the bad CO2, and transport it somewhere for storage or beneficial reuse. CO2 can be stored in under the Earth’s surface or, according to Martin Saar’s research, used in geothermal energy production.

Alright. We’re back to Professor Saar’s research. Ready to know just how he plans to sequester carbon in geothermal energy production?

It’s a simple idea, really, now that you know about geothermal energy and carbon sequestration. Prof. Saar says geothermal energy can be made even greener by replacing water with CO2 as the medium carrying heat from deep within the earth to the surface for electricity generation. In this way, waste CO2 can be sequestered and put to beneficial use! As a bonus, CO2 is even more efficient than water at transferring heat.

But don’t take my word for it. Come hear Professor Martin Saar’s lecture, CO2 – Use It Or Lose It!, yourself during the Institute on the Environment’s Frontiers on the Environment lecture series, Wednesday, October 27, 2010 from noon-1pm.

Frontiers in the Environment is free and open to the public with no registration required! The lectures are held in the Institute on the Environment’s Seminar Room (Rm. 380) of the Vocational-Technical Education Building on the St. Paul campus (map).

Jul
24
2010

June continues 4 month trend of all-time record warmth

Warmest June ever
Warmest June everCourtesy NOAA
2010 just surpassed 1998 (Feb, Jul, Aug) for the most "warmest months" in any calendar year (NOAA via Science Digest

How hot and for how long?

The July 22 Scientific American asks if this is The New Normal? A week earlier they asked, "How Much Global Warming Are We Willing to Take?

The average temperature of the planet for the next several thousand years will be determined this century—by those of us living today

Anthropocene

A new report from the National Research Council concludes that emissions of carbon dioxide from the burning of fossil fuels have ushered in a new epoch where human activities will largely determine the evolution of Earth's climate.

Time to turn it down

I hope you will check out the links above and start to consider how our decisions will impact conditions on Earth for a long time.

Jul
07
2010

Fascinating article in the June 23 issue of Science. A major puzzle of paleoclimatology is why after tens of thousands of years of glacial conditions, recent ice ages have ended with relatively sudden warm ups. Six authors have devised a comprehensive hypothesis as to why. Here is my attempt to summarize the process:

  1. First, you need very large ice sheets around the Northern Hemisphere. These ice sheets are so large that they depress the continents, pushing them down into the Earth’s mantle.
  2. Next, the Milankovitch Cycle plays a role by increasing the amount of solar energy reaching the ice sheets during summer, resulting in large amount of melt water entering the North Atlantic. Sea levels rise worldwide and encourage extensive calving of icebergs from the continental glaciers lining the North Atlantic.
  3. The freshwater and icebergs result in the formation of vast areas of winter sea ice in the North Atlantic, abruptly returning the Northern Hemisphere to glacial conditions with severe winters.
  4. The return of glacial conditions to the Northern Hemisphere affects the atmospheric circulation of the entire planet, in particular causing a southward shift of westerly winds in the Southern Hemisphere that warm Antarctica and encourage the upwelling of carbon dioxide-rich deep water in the Southern Ocean.
  5. The glacial conditions in the Northern Hemisphere last long enough to encourage prolonged off gassing of carbon dioxide from upwelling Southern Ocean deep water, resulting in the crossing of a threshold where there is enough carbon dioxide in the atmosphere to tip the whole planet into a new interglacial warm period.

If this research holds up to scientific scrutiny, it will bear on the current global warming debates. Some have interpreted the rise of carbon dioxide in the atmosphere at the end of the last ice age not as a cause of deglaciation but rather as an effect of deglaciation. These six authors see carbon dioxide as playing a key role in finally bringing to an end the last ice age because carbon dioxide is a greenhouse gas.