Editing 2889: Greenhouse Effect

{{comic
| number    = 2889
| date      = February 2, 2024
| title     = Greenhouse Effect
| image     = greenhouse_effect_2x.png
| imagesize = 740x315px
| noexpand  = true
| titletext = Once he had the answer, Arrhenius complained to his friends that he'd "wasted over a full year" doing tedious calculations by hand about "so trifling a matter" as hypothetical CO2 concentrations in far-off eras (quoted in Crawford, 1997).
}}

==Explanation==
{{incomplete|Created by CREATING CRETACEOUS PARK - Please change this comment when editing this page. Do NOT delete this tag too soon.}}
This comic has [[:Category:Climate change|climate change]] as its topic, a reccuring theme on xkcd. 

It depicts a timeline with three events: 
*The advent of the {{w|Industrial Revolution}}, marked by the introduction of the {{w|Watt steam engine}} by {{w|James Watt}} in 1776
*The first quantitative prediction of the {{w|greenhouse effect}} by {{w|Arvid Högbom}} and {{w|Svante Arrhenius}} in 1896
*And present day, early 2024. 

The distance between the start of the Industrial Revolution and the mathematical demonstration of the role of carbon dioxide as a mediator of global temperature (the "greenhouse effect") is stated to be 120 years, whilst the distance between that demonstration and the present day is 128 years. This means that we have known that greenhouse effect could cause a problem if we continued to burn fossile fules for a longer period after finding this out, than a prominant event that sent us down this path was before. Without taking any real action to prevent this. 

Climate discussions may cite [https://onlinelibrary.wiley.com/doi/abs/10.1111/j.2153-3490.1957.tb01849.x a 1957 paper by Revell and Seuss] as "the starting point" for contemporary inquiries into global warming, but the comic points out that the matter was being debated, and the underlying mechanism correctly worked out, a full half century before that. The implication, consistent with other [[:Category:Climate change|climate change]] themed xkcd comics, is that humans have taken insufficient action to slow or stop global warming despite knowing the mechanism for more than a century, and understanding, at least intellectually, the consequences of inaction.

The title text notes that the seemingly trivial prediction of CO<sub>2</sub> levels in the far future have turned out to be very important, quoting Arrhenius as believing it wouldn't be valuable at all.<ref>Crawford, Elisabeth (1997). [https://courses.seas.harvard.edu/climate/eli/Courses/EPS281r/Sources/Greenhouse-effect/Arrhenius/3-optional-Crawford-1997.pdf "Arrhenius' 1896 Model of the Greenhouse Effect in Context"]. ''Ambio'' '''26'''(1):6-11. JSTOR [https://www.jstor.org/stable/4314543 4314543].</ref>  Ironically, Arrhenius's calculations turned out to be both accurate and significant.

==Transcript==
:[At the top of the comic a timeline is shown as a long line. It has three dots, one at each end a bit inside the end of the line and one close to the middle Each dot has a gray curved line going up to it from below. Below the end of these lines a year is given. And beneath the year is a caption. Above the time line are two gray double arrows going from three gray lines above each of the three dots. The lines are broken in the middle where a label is written.]

:[Label of arrow that spans from first to second dot:]
:120 years

:[Label of arrow that spans from second to third dot:]
:128 years

:[Label for the first dot:]
:'''1776'''
:James Watt develops a steam engine that helps kick off the Industrial Revolution

:[Label for the second dot:]
:'''1896'''
:Arvid Högbom and Svante Arrhenius note that industrial activity is adding CO<sub>2</sub> to the atmosphere, and calculate how much the Earth will heat up if the CO<sub>2</sub> concentration doubles. Their answer closely matches modern estimates.

:[Label for the third dot:]
:'''2024'''
:Today

:[Caption below the panel:]
:We figured out the greenhouse effect closer to the start of the Industrial Revolution than to today.

==References==
<references/>

{{comic discussion}}

[[Category:Climate change]]
[[Category:Timelines]]
[[Category:Comics featuring real people]]