World 'needs radical cuts' on CO2

[HURAKAN]

World 'needs radical cuts' on CO2
By Tanya Syed
BBC News

More carbon dioxide needs to be absorbed than emitted by 2050 in order to prevent catastrophic climate change.

That is the conclusion of a report by the Worldwatch Institute which urges bigger cuts in greenhouse emissions.

The authors say that even a rise in temperatures of 2 degrees C poses unacceptable risks to natural systems.

But they add that it is still possible to arrest and manage climate change with renewable technologies and more efficient ways of living.

"Sealing the deal to save the global climate will require mass public support and worldwide political will to shift to renewable energy, new ways of living, and a human scale that matches the atmosphere's limits," said Robert Engelman, vice president for programmes at the Worldwatch Institute.

Commenting on the report, Ian Lowe, president of the Australian Conservation Foundation, said: "It is a persuasive call to action. Unless we take early concerted action, the impacts of climate change will overwhelm our capacity to adapt."

Ten challenges

Global greenhouse gas emissions need to peak before 2020 and decrease drastically until 2050, the report says.

More CO2 will have to be absorbed than emitted in the second half of this century.

The report, The State of the World 2009, outlines 10 key challenges that must be adopted to avoid catastrophic climate change.

These include long-term planning, global co-operation and innovative solutions such as improved building design incorporating a variety of efficiency measures.

"The report is particularly timely. It addresses climate change concerns and provides a wide range of options for tackling this multi-faceted problem," said Stephen Lincoln at the University of Adelaide in Australia.

In December 2009, government representatives from 170 countries will meet to create a global climate agreement.

The president of the Worldwatch Institute, Christopher Flavin, said: "The outcome of this meeting will be written in the history books - and in the lasting composition of the world's atmosphere."
Story from BBC NEWS:
http://news.bbc.co.uk/go/pr/fr/-/1/hi/s ... 826994.stm

[x-y-no]

More CO2 will have to be absorbed than emitted in the second half of this century.

Well that's not going to happen. Realistically, we're going to have to settle for mitigation and preparation for those ill effects that we can't stop.

[MGC]

Plant more trees.....MGC

[gigabite]

Right now the burning of fossil fuels is increasing the atmospheric carbon content by 0.4 percent per year. The problem with this heaver isotope of carbon is that plants don’t like it. Cutting fossil fuels is the only way to go.

[Sanibel]

Thanks Gigabite, I wasn't aware plants disliked the burned form of CO2.


Problem with planting more trees is human population is expanding and taking the places where more trees would be planted.

[MGC]

I happen to LOVE CARBON, I have a tendency to adorn my fingers with it. So, which isotope of carbon to trees dislike? Well, just did a google search (thus increasing my carbon footprint) and there is carbon discrimination in plant matter.....interesting.....MGC

[Sanibel]

When you produce carbon dioxide by burning it creates a certain isotope seen only in burned CO2. Fossil fuels like coal and oil create burned CO2.

[gigabite]

Paleo-climate

12C and 13C can be used as temperature tracers that explain ocean circulation. Plants find it easier to use the lighter isotopes (12C) when they convert sunlight and carbon dioxide into food , thus large blooms of plankton (free-floating organisms) draw large amounts of 12C into the oceans. If those oceans are stratified (layers of warm water near the top, and icy water deeper down) the water cannot circulate, thus when the plankton dies it sinks and carries 12C with them, making the surface layers relatively rich in 13C. Where the cold waters well up from the depths (North Atlantic) it carries the 12C with it. Thus, when the ocean was less stratified than today, there was plenty of 12C in the skeletons of surface-dwelling species. Other indicators of past climate include the presence of tropical species, coral growths rings, etc. (Flannery, 2005)

http://en.wikipedia.org/wiki/Isotopes_of_carbon

[Skyhawk]

Right now the burning of fossil fuels is increasing the atmospheric carbon content by 0.4 percent per year. The problem with this heaver isotope of carbon is that plants don’t like it. Cutting fossil fuels is the only way to go.

There are two stable isotopes of carbon C12 and C13 and one long-lived radioactive isotope C14 (and numerous very short-lived isotopes of no consequence to the discussion). C12 makes up the majority of carbon with C13 making up a little over 1% and C14 only being present in trace amounts. Plants take up C13 at a rate slightly higher than its presence in the atmosphere, but only at a slightly higher rate (see below). Organisms feeding on the plants will tend to reproduce this preference.

Now to the subject of fossil fuels. What are they? Well coal is derived from ancient plants, while oil, gas, and oil shale are derived from ancient marine organisms, which ultimately derived their carbon from phytoplankton (microscopic marine plants). Thus, one expects the carbon isotope ratios in fossil fuels to be similar to that found in plants. And thats what we see.

http://books.google.com/books?id=lWeqTPaHR7kC&pg=PA209

The delta-C13 values for plants range from -30 to -8. These are actually small numbers. The value for a sample devoid of C13 is -1000, while a sample with the same ratio as the standard has a value of zero. Also note that atmospheric CO2 has a value of -10 to -7 because the standard is a geolgically derived source. Therefore, plants have a C13/C12 ratio only slightly less that that in the atmosphere and in range found in fossil fuels.

Bottom line: The CO2 produced by burning fossil fuels is quite useable by plants because the carbon found in them originally came from plants.

[Skyhawk]

When you produce carbon dioxide by burning it creates a certain isotope seen only in burned CO2. Fossil fuels like coal and oil create burned CO2.

Burning is a chemical process not a nuclear process. It does not create a new isotope. There are two stable carbon isotopes C12 and C13 and one long-lived radioactive isotope C14 produced from nitrogen by bombardment with cosmic rays in the upper atmosphere. Nuclear processes require much higher energies than those obtained in chemical reactions. This is basic physics.

[Sanibel]

That doesn't make any difference, burned CO2 is distinguishable from unburned.

[Skyhawk]

That doesn't make any difference, burned CO2 is distinguishable from unburned.

It makes a difference it one prefers correct chemistry and physics to incorrect chemistry and physics.

I have no idea what you mean by burned CO2 vs unburned. CO2 other than that from geological processes comes from the oxidation of a carbon containing compound. Burning is just a rapid form of oxidation. It you are suggesting that burning a particular compound will produce a different isotope ratio than slowly oxidizing the same compound then that is nonsense. It you look at the link I provided, you will see that isotope ratio in coal overlaps the isotope ratio of plants; therefore the CO2 from burning the coal will be indistinguishable from that from burning a plant with the same isotope ratio.

The use of isotope ratios as diagnostics is a different subject and has the effect of changing the discussion from the question of whether the CO2 produced by burning fossil fuels will be taken up by plants. The answer to that question is, of course. The fact that there are sensitive chemical tests to distinguish the isotope ratios found in different plants or different parts of plants (leaves have less C13 than other parts) as well as different fossil fuels in no way changes the fact that CO2 from burning fossil fuels is taken up by plants and enhances their growth.

[gigabite]

The problem is the balance 13CO2/12CO2 in the atmosphere. The amount of 13CO2 in the atmosphere is increasing, because of the discrimination of plants between the two isotopes especially in seawater. This is a problem because the 13CO2 is more likely to produce carbonic acid. The heavier molecules generally have higher binding energies, the more CO2 the more carbonic acid.

[MGC]

Is 13CO2 more efficient at trapping energy in the atmosphere than 12CO2? If not than it really don't matter which isotope of carbon is in the CO2 molecule.....MGC

[gigabite]

That is a good question I was looking at endothermic reactions, because 13c depletion is a precursor to an ice age after the 13c/12c is out of balance by 20 percent.

[Sanibel]

I thought the amount of man made CO2 could be determined by analyzing the ratio of carbon 13 in older samples compared to the present balance. This would give an idea of how much CO2 man added.

[x-y-no]

I thought the amount of man made CO2 could be determined by analyzing the ratio of carbon 13 in older samples compared to the present balance. This would give an idea of how much CO2 man added.

Yes. See chapter 2 of the IPCC Fourth Assessment Report, Working Group 1. Page 139 has a discussion of this.

[Skyhawk]

I thought the amount of man made CO2 could be determined by analyzing the ratio of carbon 13 in older samples compared to the present balance. This would give an idea of how much CO2 man added.

But why use such an indirect method. We know how much coal, oil, and natural gas is burned each year; therefore, by stochiometry we know how much CO2 is produced. The latter calculation is much more accurate. The amount of CO2 produced each year is only a small fraction of the amount of CO2 that is exchanged with the ocean and vegetation during the year. Thus you are trying to detect a small signal buried in a lot of noise.

The whole issue of C13 was brought up on this thread when it was suggested that burning fossil fuels produced some sort of CO2 that could not be removed from the atmosphere by trees. That point was wrong.

[gigabite]

Are you saying that the environment has an infinite capacity to absorb CO2?

I think that you missed the point. It is not that planting trees is a bad thing. It is just not going to help adsorb hard carbon (inorganic carbon), and there is no evidence that it can.

[Skyhawk]

Are you saying that the environment has an infinite capacity to absorb CO2?

No I'm not saying that, and I didn't even suggest it. I have no idea where you got that idea. However, there is no need for infinite capacity, since there is a finite amount of fossil fuel to burn. We will ultimately have to go to nuclear and renewables and fusion if it should ever work. We should be switching now to nuclear for electric generation. Fossil fuels should be limited to transportation use, since presently there is no practical alternative. Natural gas might also be used in the interim for home heating.

Sequestration in the form of plant matter is not limited to trees. Root matter from grasses and crops mixed into the soil represents a large storage capacity.

I not sure where you learned your chemistry, but it makes no sense. CO2 is CO2 whether the carbon comes from organic or inorganic sources. There are two stable isotopes and one long-lived radioactive isotope. That's it, and all are taken up by plants. BTW fossil fuels are organic. They are produced from "cooked" plant and animal matter. Should you take an organic chemistry course, you will find that the compounds found in coal, petroleum, and natural gas will be part of the course.

An inorganic source of CO2 would be a mineral such as CaCO3.

Where are you getting your information? What is your educational background?