For any environmental scientist out there, I was wondering if an increase in CO2 levels would actually cause global warming.
My problem with this is that three are three products of combustion: CO2, water, and HEAT! As a society, we work very, very hard to produce massive amounts of heat all year round. In theory, if there was more CO2 in the air, plants should use more and balance things out. As an engineering it seems a lot more likely to me, that the heat we produce would have a lot larger effect on any over all increase.
CO2 is one of several gases in our atmosphere that contributes to the blanket of warmth our planet exhibits. If it weren’t for that, Earth would be a lot more like the moon and inhospitable to life as we know it. As far as “global warming” (actually, the debate mainly rests on anthropogenic causative agents) is concerned, the theory is that increasing CO2–>increased temperatures.
However, it is not as simple as that. There are many feedback mechanisms that contribute to overall climate, and could be kicked in by rising CO2 levels. These mechanisms can be positive (warming enhanced) or negative (warming counteracted). Such factors include heat absorption capability of the oceans and different storm/cloud patterns that would in turn affect warming trends.
What also contributes to the difficulty is that our planet has gone through ages of cyclic climate, from hotter and colder than current conditions, many times without a clear cause-and-effect-correlation with CO2 levels.
Actually, the heat you mention does show up in warming measuremnets. A fact of urbanization is the “heat island effect” where warming trends are more pronounced near urbanized areas. This is commonly seen to be a measurement artifact in trying to get a handle on global warming. It is something that has to be teased out of the CO2 data lest the issue become even more muddled.
It’s clear that the Earth has a number of negative feedback systems which keep climate in reasonable balance, since it has maintained habitable temperatures for hundreds of millions of years, during which time there have been asteroid impacts, hot and cold sun cycles, and huge variations in atmospheric greenhouse gases.
For example, increased CO2 will stimulate plant growth, which will eventually absorb more CO2. Increased CO2 and water vapor from higher temperatures will increase cloud coverage, increasing Earth’s Albedo and lowering temperatures. Etc.
The problem is that the system has hysteresis. This is a delay between the onset of a problem and a natural correction. If greenhouse gases cause a rise in global temperatures, it might take decades or centuries for the counterbalancing forces to return the temperature back to norms. Or maybe it’ll only take a few years. Or maybe the Earth has many stable points, and if you raise the temperature it’ll stabilize at a higher temperature and remain stable until some other force causes it to drop.
We just don’t know enough about the mechanisms of climate to make even reasonable guesses. There are a ton of complicating factors like warm and cold ocean currents which re-distribute heat around the planet, jet streams of air which seem to move all over the place, ice caps which expand and retreat in complex ways, and all kinds of other stuff.
It would be irresponsible to not do the best we can to try to understand these forces, but equally irresponsible to take drastic actions before the nature of the threat is really understood.
If memory from 8th grade geology serves, I seem to remeber my teacher explaining that the Earth was still coming out of the last ice age (evidence being the glaciers we still see today). I just wonder why people think we’re so damn powerful that we can change the climate a 5 billion year old planet after burning coal for 80 years. Nature is much more powerful than us and if we mess with it too much, we’ll simply be sloughed off. I for one don’t think we as a whole can destroy such a powerful force as nature.
I wouldn’t worry much about CO2 concentration increases (or decreases to “fix” the “problem”). In regards to increases in CO2 concentration causing added warming of our climate, we are at a point where further concentration increases will not cause significant temperature increases. Picture a cartesian graph of a logarithmic function. Just imagine the shape… numbers are not important. The graph spikes up sharply at first, and then flattens off at the “top”. (It may help to draw this) Now transplant that graph shape onto a coordinate system where the X axis is labeled “Greenhouse Gas Concentration”, and the Y axis is labeled “Atmospheric Temperature Due to Greenhouse Gas”, and the near verticle part of the curve intersects the origin. This represents how your typical greenhouse gas concentration effects the Earth’s atmospheric temperature. When there is none of it, it obviously has no effect on the atmospheric temperature. Adding just a little will have a sizable effect on temperature (small increase in X value causes a large increase in Y value). Adding a little more gas will have a smaller temperature effect per unit of concentration than the initial introduction of the gas. Adding more gas will have a smaller temperature effect still. Eventually, near the “top” of the graph (where the plot line is near horizontal), adding huge amounts of the gas will have an insignifficant effect on atmospheric temperature increase (huge increase in X value causes almost no increase in Y value). With specific regards to the greenhouse gas CO2, we are at the “top” of the graph. Dumping gobs (technical term) more CO2 into the atmosphere will have very little effect on our atmospheric temperature.
If you are worried about global warming, there are greenhouse gasses that are in the earlier phase of the graph, where small concentration increases will cause noticable atmospheric warming. Methane (natural gas) is one. If it is burned properly (as is seen at many refineries as stack flares), it is converted into your standard combustion products that you mentioned in the OP, and there’s nothing to worry about (although most methane in the atmosphere is the result of rotting organic matter, and is not burned). Water vapor is also in the “early” phase of the graph, but it has a quick acting natural sink (rain). CFC’s are in the “early” part of the graph, but amount to a very small fraction of the gasses responsible for the greenhouse effect. It may sound as if I am trying to discount the effects of some of these “early” phase gasses, so to be fair, the CFC’s and the methane are much more potent than CO2 at creating the greenhouse effect. IIRC, the methane can cause an atmospheric temperature increase (molecule for molecule) 23X greater than CO2. Also, IIRC, depending on the CFC, they can cause over 100X greater atmospheric temperature increases when compared to CO2.
Sorry for any spelling errors, as I am a terrible speller, and do not have access to a spell-checker (or dictionary) right now.
Things are random only insofar as we don’t understand them.
Well, if you went to 8th grade in the 70s or early 80s, you will definitely recall the “cooling crisis.” Prevailing scientific belief was that the Earth was headed for another Little Ice Age, similar to the natural cooling trend seen during the middle ages. Apocalyptic scenerios of a freezing Earth sold a lot of magazines/newspapers/books
Why would plants consume more CO2? Are you assuming an equivalent increase in plants to keep pace with the increased CO2 production?
As an engineer, you should have knowledge of empirical stoichiometery. One can be left with excess CO2. In other words, if a component (X) going into a chemical recation is more than required, the excess amount of said component will show up as simply an unreacted biproduct (X) when you go to balance the chemical equation.
“They’re coming to take me away ha-ha, ho-ho, hee-hee, to the funny farm where life is beautiful all the time… :)” - Napoleon IV
Actually, as a biology student, I know that in a controlled study with a CONSTANT number of plants, increasing the amount of CO2, causes an increase in photosynthetic activity resulting in more O2 generation–if there is an excess of light an water.
Empirical stoichiometery doesn’t work for cases in which there is a limiting reagent. Now we’re into Le Chatelier’s principle in which an increase in reagents leads to an increase in products.
Don’t forget that plants use a tremendous amount of O2 at night so that an increase in plants might not mean an increase in O2.
Sorry, I forgot to mention that with repect to the stoichiometery argument, plants use CO2, light, and water to make O2, water and sugar. CO2 is usually the limiting reagent since there is a LOT of light and water is more of a catalyst (but not exactly).