which is contributing to global warming most, co2 or ch4?

Methane is a more effective green house gas but there is very little of it in the atmosphere compared to CO2 so CO2 is currently contributing more to global warming. However, the warming temperatures are leading to methane releases from thawing permafrost and ocean clathrates so methane contributions are increasing. Methane is worse but CO2 has been the problem so far.

Both are very harmful because as the the methane and co2 go into the earths upper atmosphere it stays there forever we need methane and co2 to keep us warm and toasty but when we make to much from factories cars etc it traps in the suns heat , basically what happens is the suns rays go in to the earths atmosphere it bounces of the earth but then leaves but because of the amount of greenhouse gases some leaves but some cant because its so dense and then because the heat is trapped it has to go somewhere and eventually the earth will take it in causing it to warm up here is a website to tell you in more detail http://www.global-greenhouse-warming.com/effect-gr… this will also give you a picture whoch is really help ful

Water vapour contributes the main to warming notwithstanding if it relies upon on temperature and is a comments to different contributers. CO2, on the different hand, is the gas that contributes the 2d maximum. different gases make contributions a fragment of what those 2 gases make contributions.

Methane (CH4) is the most abundant organic molecule in the Earth’s atmosphere and plays important roles in both the planet’s radiative energy budget and global atmospheric chemistry (Brasseur et al., 1999). It’s presence in the atmosphere was first noted in 1948 from features in the infrared absorption spectrum [Migeotte, 1948] and it is now routinely measured. CH4 is the third most important greenhouse gas after H2O vapor and carbon dioxide (CO2) and has a Global Warming Potential (GWP) 25 times that of CO2 on a 1 –year timescale (Forster et al., 27).

The direct radiative forcing (warming) due to the CH4 concentration increase in the industrial era (i.e. after 1750 AD) is 0.48 W/m2 (Forster et al., 27). Increasing methane concentration also contributes a radiative forcing indirectly, through tropospheric interactions that influence ozone concentrations, increasing stratospheric water vapor (of which it is the main source), as well as providing a small additional source of CO2 (methane, in its destruction, is oxidized to CO2). If these indirect effects are taken into account, the radiative forcing due to anthropogenic (from human origin) methane increase is estimated at ~ 0.85 W/m2 , as compared to 1.66 W/m2 for CO2 (Forster et al., 27).

Methane production processes include methanogenesis by microorganisms under anoxic (without oxygen) conditions, thermogenic (heat) and abiogenic (non-living) methane production occurring below the Earth’s surface, and recently discovered, and controversial, aerobic methane production by plant matter (Keppler et al. 26). Methane destruction, in turn proceeds by the actions of oxidative methantrophic bacteria, both aerobically and anaerobically, and abiotic processes. It is the second most important sink (after carbon monoxide (CO)) of tropospheric hydroxyl radicals (·OH) (Brasseur et al., 1999). Tropospheric ·OH is the “cleaning agent” of the atmosphere and is responsible for the oxidation and removal of most organic compounds. Substantial fluctuations in CH4 concentration have the power to influence ·OH concentrations and thereby change the lifetimes of many other atmospheric trace species (Forster et al., 27). The oxidation of CH4 by ·OH is also one of the main sources of CO and formaldehyde in the troposphere (Hobbs, 20). Changes in CH4 concentration also influence tropospheric ozone production (Brasseur et al., 1999).

Methane records, along with paleo-temperature proxies, from both Antarctica (Petit, et al., 1999) and Greenland (Chappellaz, et al., 1993) reveal the close correlation between methane and millennial-scale warming and cooling. Indeed, CH4 more closely parallels the rapid variations of polar temperature records than any other measured gas (Chappellaz, et al., 1993). Humans have perturbed the atmospheric methane budget to a remarkable extent. Ice core records have shown that the CH4 concentration had remained between 350 and 8 parts per billion (ppb) for the past 650 thousand years (kyr) (Brook et al., 20; Spahni et al., 25); whereas presently global mean CH4 concentration is 1775 ppb (Forster et al., 27).

The CH4 concentration rise due to anthropogenic activities (which includes rice agriculture, ruminants (for eg. cattle), biomass burning (forest and grass fires), coal mining, and landfills) is usually considered to have begun around 1750 AD, although it is also argued that humans significantly affected the global methane budget starting around 5 kyr before present (Ruddiman, 23).

From the methane record, the CH4 concentration is seen to start to rise from ~7 ppb around 1750 AD and increased in an approximately exponential fashion until about the 1980s. In the 1990s, the rise slowed and CH4 concentration leveled off around the year 20, which has been attributed to the stabilization of the cumulative CH4 emissions (Forster et al., 27).

MY ANSWER IS BOTH. WHEN YOU COME TO A QUANTITATIVE ASPECT IT IS CO2 BUT QUALITATIVELY IT IS CH4. I MEAN IF SAME QUANTITY OF CH4 AND CO2 IA TAKEN MORE HEAT WILL BE ABSORBED BY CH4 . BUT IN NATURE THE AMOUNT OF CO2 IS FAR GREATER THAN CH4.

Source(s): I AM INTERESTED IN THIS SUBJECT AND READS MANY ARTICLES.

Your imagination.

Neither. During the last decade plus the earth has been cooling. During this same time the CO2 level has increased. If that doesn’t tickle your scientific mind, nothing will. As to CH4 (Methane) it should not be considered a GHG since it has four atoms rather than the traditional three. That was one of the original scientific definitions of GHG. It also has been repeated many times on this site.

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Carbon dioxide is what most scientists are warning about.

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Here you go.

http://en.wikipedia.org/wiki/Global-warming_potent…

Methane ch4 if a stronger GHG but very small amounts 0.017% .Co2 is 0.0398% but neither contributes much to global warming, climate change is mainly natural cycles.

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