Editing 1321: Cold

In this comic, [[Cueball]] (wearing a white knit cap with a pom-pom) and Cueball's friend (wearing a black knit cap) are walking outside in sub 0 °F (-17.8 °C). White Knit Cap Guy complains about the '''brutal''' cold and as a result questions whether {{w|global warming}} is real. Black Knit Cap Guy explains that this kind of weather used to happen all the time back before the year 2000, showing that global warming is, in fact, very real.

This is illustrated in panel two by a graph showing the number of days with sub 0 °F as a function of year from 1970 to 2013 in the city of {{w|St. Louis}}, (where we learn that Cueball is from). It shows that these days used to be rather common between 1970 and 1999, only to be completely absent for the next 14 years until and including 2013. A [http://www.rcc-acis.org/climatecentral source link] for this graph is provided (though as of June 2014, the link is dead - see [[#Trivia|Trivia]] below).

Cueball's friend uses this graph to explain that not a single day like this has happened since 2000, until here in 2014 where a {{w|polar vortex}} pushed the temperature down below zero again for two days. Since this weather is now unusual and infrequently experienced, people in St. Louis perceive it as being very cold because they have since adapted and are now unused to this sort of temperature, even though this was a common temperature to reach in past decades. This is further demonstrated when Cueball remarks that it's "too cold". Subzero {{w|Fahrenheit}} temperatures are very cold to be out in. See for instance the first panel of [[526: Converting to Metric]].

In the last panel, in a future St. Louis, a [[Cueball]] discovers a thin sheet of ice, suggesting the temperature has fallen just below 32 °F (0 °C), the freezing point of water. The suggestion here is that the environment has warmed to such an extent that temperatures below 32 degrees F are very unusual, and the future Cueball repeats the same short-term fallacy that such "extreme cold" disproves global warming. Someone off-panel, presumably another Black Knit Cap Guy, sighs as the cycle continues.

The comic reacts to a simplified view of {{w|global warming}} by amateurs, including media, who fail to understand (or choose to ignore) the difference between {{w|climate}} and {{w|weather}}. Short, random weather fluctuations like the polar vortex are taken as examples or counter-examples of climate change and global warming. To understand climate change, one must look at global (not local) and long-term (not short-term) temperature trends.

Debates on the theory of global warming/climate change often center on whether the current warming trend is primarily caused by humans or is a natural change, as has happened in the past. Within the scientific community, there is an overwhelming consensus that the current trend is {{w|Human impact on the environment|anthropogenic}} (i.e. man-made), but many in the general public (including many politicians) are hesitant to accept this. There is clearly no doubt about where [[Randall]] stands on this debate, as many of his comics and blog posts continue to plead for humanity to do something about the ''man-made'' global warming trend - especially in comic [[1379: 4.5 Degrees]].

The title text suggests that gathering data about global warming is time-consuming and is the kind of stuff only a real nerd would do. Most people would rather hang out with friends, or at least spend their time with some more fun nerd activity. Randall has been known to use the title text to poke fun at himself over how much time he has spent researching topics and more generally how geeky his interests tend to be. Although the title text tries to deny this geeky behavior, he cannot help himself at the end by mentioning another ''interesting'' climate subject: ''Snowfall records''.

Climate change, especially global warming, is a [[:Category:Climate change|recurring theme]] in xkcd.

:White Knit Cap Guy: It is '''''brutal''''' out. So much for global warming, huh?

:[A dot plot showing number of days with lows below zero Fahrenheit by year since 1970.]

:Black Knit Cap Guy (off-screen): On average, it used to get below 0 °F there a handful of days per year.

:[Above the dot plot to the left is a label in a black frame:]

:[Below the dot plot are written the years:]

:Black Knit Cap Guy: Then, in 2014, when the first polar vortex hit, it dipped below zero for two days.

:Black Knit Cap Guy: And everyone freaked out

:Black Knit Cap Guy: because what used to be normal

:Black Knit Cap Guy: now feels too cold.

*[http://assets.climatecentral.org/pdfs/TVMFrigidNights2014_stlouis_med.jpg The graph] can still be found in Climate Central's assets. The graph is used to illustrate the point in the following article: ''[http://www.climatecentral.org/news/extreme-cold-events-in-a-climate-context-16931 Extreme Cold is Becoming More Rare]'' were similar graphs are shown or referenced for many other US cities.

**The maximum was 13 subzero days in 1984, but no less than three years had more than 10 subzero days.

**As these record years are all in the 8-year period from 1977 to 1984, no less than 52 of these 89 subzero days occurred in those years.

**Here are the number of days from 1970 to 2000 as read of the graph:

***1970 - 4; 1971 - 0; 1972 - 4; 1973 - 0; 1974 - 4; 1975 - 0; 1976 - 1; 1977 - 11; 1978 - 5; 1979 - 8; 1980 - 1; 1981 - 3; 1982 - 11; 1983 - 0; 1984 - 13; 1985 - 2; 1986 - 1; 1987 - 0; 1988 - 1; 1989 - 0; 1990 - 5; 1991 - 0; 1992 - 0; 1993 - 1; 1994 - 3; 1995 - 0; 1996 - 3; 1997 - 6; 1998 - 0; 1999 - 2; 2000 - 0;

'''Note''' that this is not the same data set as mentioned in xkcd as this is regarding '''freezing''' days and not '''subzero''' days!

With the full [http://www.crh.noaa.gov/images/lsx/climate/stl/temp/temp_stl_ranked_32_0_occurrence.xls excel dataset] of the number of freezing days (i.e. below 32 °F) as obtained from the {{w|National Oceanic and Atmospheric Administration}}'s homepage [http://www.crh.noaa.gov/lsx/?n=cli_archive NOAA] you get the following plot:

*Blue points: Number of freezing days (<32&nbsp;°F) for that year

*Red points: Number of freezing days averaged over 10 years (to make trending more readable)

*X-axis is the year (1874..2013)

*Y-axis is the number of days temperature is below 32&nbsp;°F for St. Louis

From the same dataset [http://www.crh.noaa.gov/images/lsx/climate/stl/temp/temp_stl_ranked_32_0_occurrence.xls excel dataset] we can also get the number of sub-zero days i.e. below 0&nbsp;°F (which are those mentioned in the XKCD strip) - plotting those and you get the following plot:

 

 

 

 

So while '''weather is different every year''' (which is also illustrated by the outliers) the '''climate is defined by the long term trend''' - which is the point of this cartoon.