39

According to the Intergovernmental Panel on Climate Change (IPCC): "Greenhouse gases are those that absorb and emit infrared radiation in the wavelength range emitted by Earth." In order for a molecule to absorb and emit in the infrared (IR) region, its chemical bonds must rotate and vibrate in a manner that affects something called the molecule's ...


38

An article by Snell and Pleasanton, 'The Atomic and Molecular Consequenses of Radioactive Decay', (J. Phys. Chem., 62 (11), pp 1377–1382, $1958$) supports Ben Norris's comment. It is clear ... that $\ce{C^{14}O2}$ remains predominantly bound as $\ce{NO2+}$, a result that is perhaps not surprising. [This occurs in] $81$% of the decays. In $\ce{C^{14}O2 -&...


31

The atmosphere actually loses gases to outer space. The average velocity $\bar v$ of gas molecules is determined by temperature $T$. However, not all the molecules travel with the same velocity. The probability of finding a molecule with a velocity near $v$ is described by the Maxwell distribution of speeds $$\begin{align} f{\left(v\right)}&=4\pi\sqrt{{\...


24

This is very hard to answer precisely, as there are many different carbon capture strategies, and economics at the scale required is quite different from our normal understanding. However, I'd love to see some attempts to at least get order of magnitude estimates, or sources with more in-depth analyses. Here is an implementation of carbon capture and ...


24

The antineutrino is not completely irrelevant. The decay energy is shared between the beta particle and the neutrino. Therefore, the beta particles appear with an energy distribution that ranges from zero to the maximum beta energy. The maximum beta energy for the decay of $\ce{^14C}$ is $E_\text{max}=0.1565\ \mathrm{MeV}$; the average beta energy is $E_\...


20

When heat is leaving earth it leaves as infrared radiation. Greenhouse gases are gases that are able to absorb this infrared radiation. If we look at the infrared emission spectrum from Earth[1]: We can see that between $\pu{400 cm-1}$ and $\pu{700 cm-1}$, a lot of the infrared radiation is absorbed by $\ce{CO2}$. Gases like $\ce{N2}$ and $\ce{O2}$ don't ...


17

Since the stratosphere is nowhere near a closed system, a chlorine atom will eventually leave it. Look at the phrasing again: It is estimated that one chlorine atom can destroy over 100,000 ozone molecules before it is removed from the stratosphere. It is not stated, that it looses its potential, it just leaves the region, where there is sufficient ozone ...


13

That's because of two reasons. One is entropy, the ultimate force of chaos and disorder. Sure, gases would like to be arranged according to their density, but even above that, they would like to be mixed, because mixing creates a great deal of entropy. If you prevent the mixing, then they would behave just as you expected. Indeed, a balloon filled with $\ce{...


13

There seem to be three processes to consider here: As the high-energy electron exits, it creates a rapidly varying electrical current, which produces intense electromagnetic fields for a short time. This may act on the other charged particles that are present, possibly creating further ionization and/or breaking the chemical bond. The nitrogen nucleus ...


11

There is good information at Glowing Gases - Aurorae There are many factors that need to be considered. Once an atom or molecule is excited, it can lose the energy by collision or by emission of light. The longer the lifetime of the excited state, the higher the altitude is required to make radiation vs. collision the way energy is lost. The atomic ...


11

Usually when we say something "burns", it's being oxidized. In the case of carbon dioxide only the oxygen can be oxidized, by displacing it as the element; that requires fluorine or a sufficiently powerful fluorinating agent. Carbon dioxide supports combustion, acting as the oxidizer instead of being oxidized, with some active metals such as magnesium. ...


11

There are a few problems with what you're proposing: The reaction requires energy. Where do get the methane from? What will you do with the carbon you're generating? The energy problem can be solved by using surplus energy from renewable source like solar and wind, but, as airhuff also mentiond in a comment, there is much more CO2 in the atmosphere than ...


10

With reference to the discussion in the question comments, this product does not appear to appreciably reduce carbon emissions in total. It does however appear to reduce carbon monoxide emissions. As carbon monoxide is a product of incomplete combustion, it is plausible that the additive is helping the fuel burn more completely. Broadly speaking, you would ...


10

You make the assumption that the ozone concentration in the upper atmosphere is in equilibrium. It isn't. $\ce{O3}$ is a much less stable molecule than $\ce{O2}$ (the heat of formation from $\ce{3/2 O2}$ is $143~\mathrm{kJ/mol}$) and the concentration at equilibrium would be very low. A significant concentration exists in the upper atmosphere because $\ce{...


9

wikipedia article cites: "After production in the upper atmosphere, the carbon-14 atoms react rapidly to form mostly (about 93%) 14CO (carbon monoxide), which subsequently oxidizes at a slower rate to form 14CO2, radioactive carbon dioxide. The gas mixes rapidly and becomes evenly distributed throughout the atmosphere (the mixing timescale in the order of ...


8

Oxygen/nitrogen ratios vary seasonally and geographically even at sea level on the order of 200 ppm. Oxygen concentration has also been slowly decreasing in correlation with carbon dioxide increase. Try using the MSIS-E-90 Atmosphere Model which allow location, date, time and height input and provides composition output.


8

It's... feasible. There are a number of technologies that are being considered. Costs will be high, some number of billions or trillions: you're talking planetary engineering, here. The most obvious option is to plant trees. The obvious problem with that is that even planting them at the same speed as they are being removed is infeasible. Unfortunately ...


7

"Give me a half a tanker of iron and I will give you another ice age" That's the claim of people who believe in iron seeding the ocean. The link claims that "the addition of silicic acid or choosing the proper location could, at least theoretically, eliminate and exceed all man-made CO2", but no citation is given. As to cost? "Current estimates of the ...


7

First we have to look how the greenhouse effect works for all gases: Light with a wavelength not absorbed by the atmosphere gets absorbed by the soil and heats up the earth. Because of black body radiation for 300K the earth starts to emit light itself with a maximum in the IR spectrum. Light with this frequency gets readily absorbed by vibrational ...


7

Current concentrations of $\ce{CO2}$ and $\ce{CH4}$ in the atmosphere are around 390 ppmv and 1.75 ppmv, resp. These concentrations and the wish to obtain large quantities of both gases rapidly seem mutually exclusive, unless you use (at least one) additional carbon source. Taking the options for interconversion into account, $\ce{CH4}$ in pressurized ...


7

It could be possible that you're thinking of the overall lifetime of $\ce{NO_x}$ ($\ce{NO2 + NO}$), which indeed does have a longer atmospheric lifetime than $\ce{NO}$ individually and which even, at around 5 km altitude, has a lifetime of ~4 days. The two interconvert during the day due to photo-chemistry, and the ratio of the two is dependent on the ...


7

The 'heat is not reflected off the carbon dioxide' but instead the gas absorbs some of the ir radiation from the sun and that also radiated from the earth. The fact that carbon dioxide (or methane) can absorb and emit infra-red radiation is only part of the process for the greenhouse effect. Equally important is the fact that oxygen and nitrogen molecules do ...


7

$\ce{CO}$ is not considered a primary (or significant) greenhouse gas due to the weak (but non-zero) absorption of energy in the infrared. However, it does increase global warming by reacting with certain chemical species in the atmosphere which in turn lead to an increase in concentration of primary greenhouse gasses, most notably methane and ozone (see ...


6

The most powerful Greenhouse Effect gas of all is water. Run a vaporizer to 100% humidity http://disc.sci.gsfc.nasa.gov/featured-items/images/fig2_air_infrared_spectrum to 50 microns http://earthobservatory.nasa.gov/Features/Tyndall/Images/absorption.gif to 15 microns, near IR The Greenhouse effect incremental champ is a tank of $\ce{SF6}$ (...


6

According to Wikipedia, Martin is correct; a chlorine molecule, being slightly heavier than oxygen, will eventually be transported out of the ozone layer back to the troposphere (taking approximately 2 years to do so). Additionally, presence of other atoms in the ozone layer have a small chance of destroying the radical chlorine, causing it to form $\ce{HCl}$...


6

Here's how you can get a quantitative handle on this. Suppose you have a tall column of two gases with molecular weights $M_1$ and $M_2$ in a cylindrical container of height $L$ and cross sectional area $A$, and you have the amount of substances $n_1$ and $n_2$ of each gas, respectively, in the container. Suppose that the gases can be treated as ideal ...


5

When you're dealing with questions like "how well does this burn", you are intrinsically dealing with the reaction rate of the combustion reaction. When looking at chemical reaction rates, they are typically proportional to the "chemical activity" of the species reacting. (There's complications due to the stoichiometry of the reaction, but those corrections ...


5

According to the Encyclopedia Britannica, to somewhat paraphrase this non-technical source, the reaction rate of $\ce{O2(g)}$ and $\ce{H2(g)}$ at atmospheric pressure is not measurable at any mixing ratio at temperatures below $\ce{300^oC}$. Unfortunately that source does not report what kind of experimental detection limits define what "not measurable" ...


5

No. ppmw means parts per million by weight (mass). This is not the same as mg/m3, which is milligrams (mass) per cubic meter (volume). For example, in a gas of very low density (e.g. $\ce{CO2}$ at 10-6 Pa), 1 mg/m3 could exceed the weight of $\ce{CO2}$, i.e. would be greater than 900,000 ppmw. One measure has to do with mass in a given volume, the other ...


5

This phenomenon is already explained in this website, but I will paraphrase it. All images here are from that website. The atomic oxygen causes the green and the red color, while diatomic nitrogen causes blue and red: The effect of altitude on the color is not explained. However, an explanation is found on Wikipedia: The highest altitudes have fewer ...


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