use subscript 2 in "CO₂" in emissions plot y-axis label

[cjyetman]

Not sure how to achieve this in this context, but it would be preferable to show "CO₂" instead of "CO2"

pacta.portfolio.report/R/prep_emissions_trajectory.R

Lines 12 to 21 in de3e1f8

	emissions_units <-
	c(
	Automotive = "tons of CO2 per km per cars produced",
	Aviation = "tons of CO2 per passenger km per active planes",
	Cement = "tons of CO2 per tons of cement",
	Coal = "tons of CO2 per tons of coal",
	`Oil&Gas` = "tons of CO2 per GJ",
	Power = "tons of CO2 per MWh",
	Steel = "tons of CO2 per tons of steel"
	)

[cjyetman]

"CO₂" can be written in ASCII in R by using a unicode escape

"CO\U00002082"
#> [1] "CO₂"

so this could be written as...

 emissions_units <- 
   c( 
     Automotive = "tons of CO\U00002082 per km per cars produced", 
     Aviation = "tons of CO\U00002082 per passenger km per active planes", 
     Cement = "tons of CO\U00002082 per tons of cement", 
     Coal = "tons of CO\U00002082 per tons of coal", 
     `Oil&Gas` = "tons of CO\U00002082 per GJ", 
     Power = "tons of CO\U00002082 per MWh", 
     Steel = "tons of CO\U00002082 per tons of steel" 
   )