Why are the British tweeting about climate change at night?

Points of post:

•  To demonstrate how the library twitteR can be combined with mapping capabilities of ggplot

• To reveal the locations of people tweeting about climate change at two points in time.

• To show that climate change tweeters are mostly from the developed world.

• To show that some (sad) tweeters are twittering about climate change in the middle of the night.

In a previous blog post, we used twitteR and wordcloud to summarize which other words were occurring in tweets (combined from around the world) together with the keywords, ‘climate-change’ and ‘Bangladesh’ at two arbitrarily selected time-points. 

The geo-locations of tweets are, however, also often available and are potentially very interesting and revealing. 

Fifteen-hundred (1500) is the maximum number of tweets that can be captured using the twitteR library with one call.  There probably are ways to get more data but we guess you probably have then to spend money. 

Here we used #climatechange because it coincided with the last days of COP20 in Lima, Peru which ran from 1^st to 12^th December 2014.  It is an extremely important global forum at which nations can meet and discuss their options for reducing carbon emissions, see http://unfccc.int/meetings/lima_dec_2014/meeting/8141.php)

The first ‘tweet map’ (below) we produced is based on approximately 1500 geo-located tweets that contained the hash-tag, #climatechange, and which were ‘tweeted’ at about 10am GMT on the 11^th December 2014. It shows that #climatechange tweets were coming from 4 main areas: North America, Europe, India and Australia. There didn’t appear either to be too many tweets coming out of Lima which surprised us. Maybe the delegates were too busy enjoying the South-American hospitality, and catching up with old mates to take much interest in Climate Change!

Geo-located tweets with #climatechange tweeted at around 10am GMT 11th December 2014

The second ‘tweet-map’ (below), also based on approximately 1500 geo-located #climatechange tweets, is for a snapshot that took place at 5 hours later at around 3am GMT on the final day of the conference (12^th December 2014).  The overall pattern between the maps remains the same but the relative frequency of #climatechange tweeters from Europe, as compared to North America, has increased. People in the United Kingdom were particularly keen, twittering like mad about climate change at 3am. Why? We don’t know.

Geo-located tweets with #climatechange tweeted at around 3am GMT 12th December 2014

Note that tweets are geo-located, either by exploiting the users’ location as defined in their profile, or by ascertaining the exact location directly  if allowed by the user. This can be effected, either from GPS-enabled software which many people have installed on their smart-phones, or by using an IP-address.  This means that not all tweets can be geo-located with any great precision. Some are only geo-located at the National and/or regional levels, as evident from the large circle in the middle of Australia. That’s to say these cautious tweeters only gave ‘Australia’ as their location.

As we have explained in an earlier blog post on worldclouds and twitteR, to pull the data from Twitter using its API, you will need to have a Twitter account and carry out a 'twitter authentication'.  The R code to perform a search on twitter for the selected 'term(s)' and mapping them out is detailed below.

# Load required libraries
 
library(RCurl)
library(maps)
library(stringr)
library(tm)
library(twitteR)
library(streamR)
library(grid)
library(ggplot2)
library(rgdal)
library(ggmap)
 
# Set working directory
 
setwd("D:/ClimData/")
 
#### Fonts on Windows ####
windowsFonts(ClearSans="TT Clear Sans")
 
# Load Credentials
 
load("D:/ClimData/Twitter/twitter authentification.Rdata")
registerTwitterOAuth(twitCred)
options(RCurlOptions = list(cainfo = system.file("CurlSSL", "cacert.pem", package = "RCurl")))
 
# Search term on twitter
 
searchTerm <- "#climatechange"
searchResults <- searchTwitter(searchTerm,n=1500,since='2014-12-11', until='2014-12-12')  
tweetFrame <- twListToDF(searchResults) 
 
userInfo <- lookupUsers(tweetFrame$screenName)  
userFrame <- twListToDF(userInfo)
 
locatedUsers <- !is.na(userFrame$location)
 
# Geocode locations using 'ggpmap' library
 
locations <- geocode(userFrame$location[locatedUsers])
 
locations_robin <- project(as.matrix(locations), "+proj=robin")
 
locations_robin_df <- as.data.frame(locations_robin)
 
# Import world boundaries
 
world <- readOGR(dsn="D:/Data/ne_10m_admin_0_countries", layer="ne_10m_admin_0_countries")
 
world_robin <- spTransform(world, CRS("+proj=robin"))
 
world_robin_df <- fortify(world_robin)
 
counts <- aggregate(locations_robin_df$V1,by=list(x=locations_robin_df$V1,y=locations_robin_df$V2),length)
names(counts)[3] <- "count"
 
# Theme options for Map
 
theme_opts <- list(theme(panel.grid.minor = element_blank(),
                         panel.grid.major = element_blank(),
                         panel.background = element_blank(),
                         panel.border = element_blank(),
                         plot.background = element_blank(),
                         axis.line = element_blank(),
                         axis.text.x = element_blank(),
                         axis.text.y = element_blank(),
                         axis.ticks = element_blank(),
                         axis.title.x = element_blank(),
                         axis.title.y = element_blank(),
                         legend.position = "bottom",
                         legend.key = element_blank(),
                         legend.title = element_text(colour="black", size=12, face="bold",family="Clear Sans"),
                         legend.text = element_text(colour="black", size=10, face="bold",family="Clear Sans"),
                         plot.title = element_text(size=15,face="bold",lineheight=0.5,family="Clear Sans")))
 
# Plot map and tweet counts 
 
tp <- ggplot(world_robin_df)+
      geom_polygon(aes(x = long, y = lat, group = group), fill = "grey20")+
      geom_path(aes(x = long, y = lat, group = group),colour = "grey40", lwd = 0.2)+
      geom_point(data= counts, aes(x=x,y=y,size=count),color="#32caf6", alpha=I(8/10))+
      scale_size_continuous(name="Number of tweets")+
      ggtitle("Twitter Map of #climatechange\n")+
      xlab("")+ ylab("")+
      coord_equal()+
      theme_bw() + 
      guides(size = guide_legend(title.position = "top",title.hjust =0.5))+
      theme_opts
 
tp
 
# Save to png
 
ggsave(tp,file="D:/Twitter_ClimateChange_Map.png",dpi=500,w=10,h=6,unit="in",type="cairo-png")

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