2016 Will Be The Warmest Year, But This Is How Deniers Will Spin It

R code for the analysis supporting this December 20, 2016 BuzzFeed News article on the likelihood that 2016 will be the warmest year on record, and how that is being spun by deniers of climate science. Supporting files are in this GitHub repository.

Data preparation

The following code loads data on the average global temperature from the National Oceanic and Atmospheric Adminstration for each month since January 1880.

It creates the columns Year, Date (to plot the entire temperature timeline), Date_2016 (with the monthly data for each year transposed to 2016, allowing all the data to be readily plotted on one yearly plot), and Weight (to allow the data for 2016 to be distinguished in the initial animation). The column Value gives the global average temperature, recorded as the difference from the global average for the 20th century for each month.

# load required packages
library(dplyr)
library(readr)

# load and process global temp data
global_temp <- read_csv("https://www.ncdc.noaa.gov/cag/time-series/global/globe/land_ocean/all/12/1880-2016.csv", skip = 3) %>%
  rename(Yr_Mo = Year) %>%
  mutate(Year = as.integer(substr(Yr_Mo,1,4)),
         Date = as.Date(paste0(substr(Yr_Mo,1,4),
                       "-",
                       substr(Yr_Mo,5,6),
                       "-01")),
         Date_2016 = as.Date(paste0("2016-",
                               substr(Yr_Mo,5,6),
                               "-01")),
         Weight = ifelse(Year == 2016,2,1))

Charts

To create animations from this code, you will need to install ImageMagick.

Animation of average global temperature by year

# load required packages
library(ggplot2)
library(gganimate)

# set palette and values for breaks
pal <- c("#313695","#4575b4","#74add1","#abd9e9","#e0f3f8","#ffffbf","#fee090","#fdae61","#f46d43","#d73027","#a50026")
values <- seq(-2, 2, length = 11)

# global temperature animation
temp_anim <- ggplot(global_temp, aes(x=Date_2016, y=Value, color = Value, group = Year, frame = Year, cumulative = TRUE)) +
  geom_path(aes(size=Weight, alpha=Weight)) + 
  scale_size_continuous(range = c(0.5, 1), guide = FALSE) +
  scale_alpha_continuous(range = c(0.5, 1), guide = FALSE) +
  theme_dark(base_size = 20, base_family = "Proxima Nova Semibold") +
  scale_color_gradientn(colors = pal, values=values, rescaler = function(x, ...) x, oob = identity, guide = FALSE) +
  ylab("Diff. from C20th average (ºC)") +
  xlab("") +
  scale_x_date(date_labels = "%b",
               date_breaks = "month") +
  theme(panel.grid.minor = element_blank())

# save as GIF
gg_animate(temp_anim, "temp_anim.gif", ani.width = 625, ani.height = 350,  interval = 0.05)

# increase delay on final frame
system("convert temp_anim.gif \\( +clone -set delay 300 \\) +swap +delete  temp_anim_with_pause.gif")