This graph shows changes in <a href="https://en.wikipedia.org/wiki/radiative_forcing" class="extiw" title="en:radiative forcing">radiative forcing</a> of long-lived greenhouse gases between 1979-2012. These gases are <a href="https://en.wikipedia.org/wiki/carbon_dioxide" class="extiw" title="en:carbon dioxide">carbon dioxide</a> (CO<sub>2</sub>), <a href="https://en.wikipedia.org/wiki/methane" class="extiw" title="en:methane">methane</a> (CH<sub>4</sub>), <a href="https://en.wikipedia.org/wiki/nitrous_oxide" class="extiw" title="en:nitrous oxide">nitrous oxide</a> (N<sub>2</sub>O), chlorofluorocarbon-12 (<a href="https://en.wikipedia.org/wiki/CFC-12" class="extiw" title="en:CFC-12">CFC-12</a>), <a href="https://en.wikipedia.org/wiki/CFC-11" class="extiw" title="en:CFC-11">CFC-11</a>, and fifteen other minor, long-lived, <a href="https://en.wikipedia.org/wiki/halogen" class="extiw" title="en:halogen">halogenated</a> gases. The 15 other halogenated gases are <a href="https://en.wikipedia.org/wiki/CFC-113" class="extiw" title="en:CFC-113">CFC-113</a>, <a href="https://en.wikipedia.org/wiki/tetrachloromethane" class="extiw" title="en:tetrachloromethane">tetrachloromethane</a> (CCl<sub>4</sub>), <a href="https://en.wikipedia.org/wiki/trichloromethane" class="extiw" title="en:trichloromethane">trichloromethane</a> (CH<sub>3</sub>CCl<sub>3</sub>); hydrochlorofluorocarbons (HCFCs) <a href="https://en.wikipedia.org/wiki/HCFC-22" class="extiw" title="en:HCFC-22">22</a>, <a href="https://en.wikipedia.org/wiki/HCFC-141b" class="extiw" title="en:HCFC-141b">141b</a> and <a href="https://en.wikipedia.org/wiki/HCFC-142b" class="extiw" title="en:HCFC-142b">142b</a>; <a href="https://en.wikipedia.org/wiki/hydrofluorocarbon" class="extiw" title="en:hydrofluorocarbon">hydrofluorocarbons</a> (HFCs) <a href="https://en.wikipedia.org/wiki/HFC-134A" class="extiw" title="en:HFC-134A">134a</a>, <a href="https://en.wikipedia.org/wiki/HFC-152A" class="extiw" title="en:HFC-152A">152a</a>, <a href="https://en.wikipedia.org/wiki/HFC-23" class="extiw" title="en:HFC-23">23</a>, <a href="https://en.wikipedia.org/wiki/HFC-143a" class="extiw" title="en:HFC-143a">143a</a>, and <a href="https://en.wikipedia.org/wiki/HFC-125" class="extiw" title="en:HFC-125">125</a>; <a href="https://en.wikipedia.org/wiki/sulfur_hexafluoride" class="extiw" title="en:sulfur hexafluoride">sulfur hexafluoride</a> (SF<sub>6</sub>), and halons <a href="https://en.wikipedia.org/wiki/halon_1211" class="extiw" title="en:halon 1211">1211</a>, <a href="https://en.wikipedia.org/wiki/halon_1301" class="extiw" title="en:halon 1301">1301</a> and <a href="https://en.wikipedia.org/wiki/halon_2402" class="extiw" title="en:halon 2402">2402</a>). The graph does not include other forcings, such as aerosols and changes in solar activity.
<p><i>Summary</i>
</p><p>Total forcing in 1979 was 1.712 <a href="https://en.wikipedia.org/wiki/watt" class="extiw" title="en:watt">watts</a> per square metre (W.m<sup>-2</sup>), and has steadily increased over time to 2.873 W.m<sup>-2</sup> in 2012. Between 1979-2012, the largest contributors to radiative forcing have been CO<sub>2</sub> and CH<sub>4</sub>. In 2012, the percentage contributions of each gas to total forcing was approximately:
</p>
<ul><li>CO<sub>2</sub>: 64%</li>
<li>CH<sub>4</sub>: 18%</li>
<li>N<sub>2</sub>O: 6%</li>
<li>CFC-12: 6%</li>
<li>CFC-11: 2%</li>
<li>15 minor gases: 4%</li></ul><p>Forcing data are briefly summarized below. All the data are available in a later section as comma-separated values. The first value is the year, followed by forcing values (in W.m<sup>-2</sup>) for CO<sub>2</sub>, CH<sub>4</sub>, N<sub>2</sub>O, CFC-12, CFC-11, the 15-minor halogenated gases, and total forcing, respectively:
</p>
<ul><li>1979: 1.027, 0.419, 0.104, 0.092, 0.039, 0.031, 1.712</li>
<li>1980: 1.058, 0.426, 0.104, 0.097, 0.042, 0.034, 1.761</li>
<li>1990: 1.293, 0.472, 0.129, 0.154, 0.065, 0.065, 2.178</li>
<li>2000: 1.513, 0.494, 0.151, 0.173, 0.066, 0.083, 2.481</li>
<li>2010: 1.791, 0.504, 0.174, 0.170, 0.060, 0.106, 2.805</li>
<li>2012: 1.846, 0.507, 0.181, 0.168, 0.059, 0.111, 2.873</li></ul><p><i>References:</i>
</p>
<ul><li>Butler, J.H. and S.A. Montzka (<span class="mw-formatted-date" title="2013-08-01">2013-08-01</span>) <cite>THE NOAA ANNUAL GREENHOUSE GAS INDEX (AGGI)</cite><sup><a rel="nofollow" class="external autonumber" href="http://www.esrl.noaa.gov/gmd/aggi/aggi.html">[1]</a></sup>, NOAA/ESRL Global Monitoring Division</li></ul>
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<span class="int-own-work" lang="en">Own work</span>