CO2 has gone up around 30% since the industrial revolution, yet humans contribute 3% of its total. Is it possible for this to build up to a 30% increase or does it mean other areas contributed to that increase as well as human activity?

Zbeckabee

Carbon dioxide may be obtained from air distillation. However, this yields only very small quantities of CO2. A large variety of chemical reactions yield carbon dioxide, such as the reaction between most acids and most metal carbonates. For example, the reaction between hydrochloric acid and calcium carbonate (limestone or chalk) is depicted below: 2 HCl + CaCO3 �¨ CaCl2 + H2CO3 The H2CO3 then decomposes to water and CO2. Such reactions are accompanied by foaming or bubbling, or both. In industry such reactions are widespread because they can be used to neutralize waste acid streams. The production of quicklime (CaO) a chemical that has widespread use, from limestone by heating at about 850 �‹C also produces CO2: CaCO3 �¨ CaO + CO2 The combustion of all carbon containing fuels, such as methane (natural gas), petroleum distillates (gasoline, diesel, kerosene, propane), but also of coal and wood, will yield carbon dioxide and, in most cases, water. As an example the chemical reaction between methane and oxygen is given below. CH4 + 2 O2 �¨ CO2 + 2 H2O Yeast metabolizes sugar to produce carbon dioxide and ethanol, also known as alcohol, in the production of wines, beers and other spirits, but also in the production of bioethanol: C6H12O6 �¨ 2 CO2 + 2 C2H5OH All aerobic organisms produce CO2 when they oxidize carbohydrates, fatty acids, and proteins in the mitochondria of cells. The large number of reactions involved are exceedingly complex and not described easily. Refer to (cellular respiration, anaerobic respiration and photosynthesis). Photoautotrophs (i.e. plants, cyanobacteria) use another modus operandi: Plants absorb CO2 from the air, and, together with water, react it to form carbohydrates: nCO2 + nH2O �¨ (CH2O)n + nO2 For more...see ISOLATION AND PRODUCTION: http://en.wikipedia.org/wiki/Co2#Isolation_and_production http://en.wikipedia.org/wiki/Greenhouse_gas http://timeforchange.org/CO2-cause-of-global-warming http://www.theresilientearth.com/?q=content/warming-caused-soot-not-co2 Jun 29 10, 12:53 PM

satguru

These are clearly the natural sources but as accused of adding 30% through industrial activity, despite it only being 3% of the total emitted can this all build up to the current 30% increase alone? Jun 29 10, 3:33 PM

Arpeggionist

You're measuring diferent numbers. The 3% is the amount of CO2 in the atmosphere. That number is, reportedly, 30% higher than it was two hundred years ago (in other words, it was closer to 2% then). Certainly humans have not been the only beings to add CO2 to the atmosphere, but our careless use of machinery certainly hasn't helped. Jun 29 10, 3:39 PM

satguru

That's a good bunch of links there, I think although I'm not mathematical enough to grasp the connection (or lack of) of the two figures, it seems the experts aren't agreed on them either. The 3% is man's contribution of total CO2, 380ppm is .003% (I hope that's the right number of zeros but many times less than 3). The use of machinery is accepted to contribute 3% of CO2 while the natural sources quoted above are more of a stable figure over the centuries although over the much longer term they have also changed a lot more (eg 4-5000 ppm in prehistoric times). Jun 29 10, 3:50 PM

serpa

Just how much of the "Greenhouse Effect" is caused by human activity? It is about 0.28%, if water vapor is taken into account-- about 5.53%, if not. This point is so crucial to the debate over global warming that how water vapor is or isn't factored into an analysis of Earth's greenhouse gases makes the difference between describing a significant human contribution to the greenhouse effect, or a negligible one. Water vapor constitutes Earth's most significant greenhouse gas, accounting for about 95% of Earth's greenhouse effect (5). Interestingly, many "facts and figures' regarding global warming completely ignore the powerful effects of water vapor in the greenhouse system, carelessly (perhaps, deliberately) overstating human impacts as much as 20-fold. Water vapor is 99.999% of natural origin. Other atmospheric greenhouse gases, carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), and miscellaneous other gases (CFC's, etc.), are also mostly of natural origin (except for the latter, which is mostly anthropogenic). Human activites contribute slightly to greenhouse gas concentrations through farming, manufacturing, power generation, and transportation. However, these emissions are so dwarfed in comparison to emissions from natural sources we can do nothing about, that even the most costly efforts to limit human emissions would have a very small-- perhaps undetectable-- effect on global climate. http://www.geocraft.com/WVFossils/greenhouse_data.html Jun 29 10, 7:38 PM

satguru

Serpa, I think you've sorted it very nicely! It is so complicated that without such explanations the media and governments can spin it any way they want it to look. Jun 30 10, 3:45 PM