Archive for the ‘CO2’ Category

Tale of Two Planets, or Three if you like

Tuesday, July 24th, 2007

In a New York Times editorial on July 1, 2007, Al Gore said:

We — all of us — now face a universal threat. Though it is not from outside this world, it is nevertheless cosmic in scale.

Consider this tale of two planets. Earth and Venus are almost exactly the same size, and have almost exactly the same amount of carbon. The difference is that most of the carbon on Earth is in the ground — having been deposited there by various forms of life over the last 600 million years — and most of the carbon on Venus is in the atmosphere.

As a result, while the average temperature on Earth is a pleasant 59 degrees, the average temperature on Venus is 867 degrees. True, Venus is closer to the Sun than we are, but the fault is not in our star; Venus is three times hotter on average than Mercury, which is right next to the Sun. It’s the carbon dioxide.

In the Wednesday, July 18 2007 edition of the Aspen Daily News:

Gore advised the audience to compare the blue orb of the Earth to Venus, where daytime temperatures reach 867 degrees Fahrenheit and it rains sulphuric acid. The two planets have the same amount of carbon, Gore explained, but Venus’ just happens to be in the atmosphere, while most of the Earth’s is still locked underground. “The habitability of this planet for human beings really is at risk,” he said.

True Venus is very hot, owing in part to a very thick atmosphere, composed mainly of CO2. And as Mr. Gore point out, Venus is closer to the Sun than Earth is. With no atmosphere, Mercury even though it is closer to the Sun, has a lower temperature. Both Venus and Earth would have much lower temperatures than Earth if they had no atmosphere. The Earth would be a cold ball of rock just a few degrees above absolute zero, Venus would likely be the same, maybe a few degrees warmer, maybe not.

 Gore says that Venus is three times hotter than Mercury. Not quite, Venus has a mean temperature of 740K (740 Celcius above absolute zero), Mercury’s average temperature is 440K. For Venus to be three times hotter, it would have to be 1320K. But that’s nit picking I guess, let’s just say that Venus is hot. The atmosphere of Venus is almost entirely CO2, the atmosphere of Earth has very little CO2, its a trace gas at about 56/100,000 of the total weight of all terrestrial atmospheric gases. Remember that CO2 is measured in parts per million here on Earth.

We should also keep in mind that the Earth has had times when C̘ levels were 10 times higher without causing a runaway greenhouse effect. Indeed, the early atmosphere of the Earth was primarily C̘ just like Venus. Perhaps owing to our distance from the sun, or to the action of microbes and formation of carbon-bearing rocks, C̘ levels fell until they were represented only as a trace. Is it possible to free enough carbon, by burning fossil fuels, to convert our atmosphere to a Venus-like state? No.

Even the normally Gore supporting realclimate.org says, “Is there a risk that anthropogenic global warming could kick the Earth into a runaway greenhouse state? Almost certainly not.”

But they do go on to say that “The Earth may well succumb to a runaway greenhouse as the Sun continues to brighten over the next billion years or so, but the amount of CO2 we could add to the atmosphere by burning all available fossil fuel reserves would not move us significantly closer to the runaway greenhouse threshold. There are plenty of nightmares lurking in anthropogenic global warming, but the runaway greenhouse is not among them.”

So, once again, Al Gore presents a picture of the future that may come true, albeit in a few billion years. So what is his reasoning behind making such outrageous claims? Just to scare people. That’s the problem with AGW alarmism, people become habituated (numbed) to the tales of catastrophe, so the prophets of doom, like Mr. Gore, David Suzuki, Laurie David and others, have to present ever bigger and ever scarier stories to keep the masses interested and frightened.

Original post by John Nicklin

Planting trees to save planet is pointless, say ecologists

Friday, July 20th, 2007

The Guardian, had an article on the futility of planting trees in non-tropical regions to offset global warming. The article reads: 

Planting trees to combat climate change is a waste of time, according to a study by ecologists who say that most forests do not have any overall effect on global temperature, while those furthest from the equator could actually be making global warming worse.

“The idea that you can go out and plant a tree and help reverse global warming is an appealing, feel-good thing,” said Ken Caldeira of the global ecology department at the Carnegie Institution of Washington in Stanford, California, a co-author of the study. “To plant forests to mitigate climate change outside of the tropics is a waste of time.” 

Professor Caldeira and his colleague Govindasamy Bala, of the Lawrence Livermore National Laboratory, also in California, said that outside a thin band around the equator, forests trap more heat than they help to get rid of by reducing CO2. More…

Caldeira and his colleagues ran a computer model to determine their assertions. Their premise is that boreal forests change the albedo, warming the air around the forest, grassy fields are cooler in their models. Apart from the observation that forests are cooler than open fields on hot days, and that soil in open fields traps heat whereas forest soils are cooler, their study overlooks, downplays really, the carbon sequestration represented by forests.
Chen et al, in a study called Effects of climatic variability on the annual carbon sequestration by a boreal aspen forest, found that massive amounts of carbon are sequestered in Canadian boreal areas to the extent of “40–60 Tg Carbon per year, which is 2–3% of the missing global carbon sink,” not an insignificant amount.

If the objective is to reduce carbon, then forests, boreal or tropical would still seem to be a viable alternative to many of the more technological solutions being put forward.

Caldeira found that tropical forests can reduce local air temperatures through evapo-transpiration. Given that we are cutting tropical forests at an alarming rate to plant biofuel stocks, would it not be more reasonable to plant more tropical trees as well, instead of soy beans, sugar cane and oil palms?

Caldeira also made an interesting statement, “Past 50 degrees, forests warmed the Earth by an average of 0.8C. But in the tropics forests helped cool the planet by an average of 0.7C.” This statement seems to be rather over the top, boreal forets alone have raised the GLOBAL temperature by 0.8 degrees C?

If we take the statement at face value, the net effect is 0.1 degree C, so the balance would still make boreal sequestration viable, as long as we maintain tropical forests.

Original post by John Nicklin

Mauna Loa CO2 revisited

Monday, July 16th, 2007

Here is another look at the Mauna Loa CO2 data with trend and 11 year year moving averages.

mauno-loa-co2-3.png

The rate of increase in the moving average is 1.4 ppm/year. I would be happy to post a graph from tamino, or anyone else, showing any trend that he wishes.

Original post by John Nicklin

More fun with graphs

Sunday, July 15th, 2007

Tamino suggested that I look at some data at NOAA on annual CO2 changes and that I should have some more fun with graphs. I did as he said and the graph below shows the results of plotting the raw data for 48 years. co2-change-annual.png

The average annual increase over the 48 year record is 1.4o ppm/year. Tamino claims that the rate is over 2 ppm/year. There are ups and downs in the record with a some years like 2002 and 2005 at 2.5 ppm/year and 2003 at 2.3 ppm/year. But as we are told repeatedly short term changes are not indicative of long term trends.

The graph from NOAA is repoduced here:

mauna-loa-co2.png

A rough calculation shows that C̘ levels rose by about 65 ppm over the 48 year record for an average of 1.35 ppm/year.

Original post by John Nicklin