CS_15.md

title	week	type
Final Challenge	12	Case Study

Write a short script to perform the following steps

1. Import the data on atmospheric $CO_2$ from the link below into R

data_url="http://scrippsco2.ucsd.edu/assets/data/atmospheric/stations/in_situ_co2/monthly/monthly_in_situ_co2_mlo.csv"

2. Remove the header of the file to retain only the data
3. Filter out missing data (-99.99)
4. Update the column names using the colnames vector below

colnames=c("year","month","excel","decimal_year","co2","co2_seasonal","co2_fit","co2_seasonalfit","co2_filled","co2_seasonalfilled")

5. Calculate the mean $CO_2$ for each year from the co2 column
6. plot a simple ggplot line graph of mean annual $CO_2$ concentration each year as shown below

## Response [https://scrippsco2.ucsd.edu/assets/data/atmospheric/stations/in_situ_co2/monthly/monthly_in_situ_co2_mlo.csv]
##   Date: 2020-12-10 14:50
##   Status: 200
##   Content-Type: text/csv
##   Size: 75.7 kB
## <ON DISK>  /var/folders/fh/g_hk6yxx4cj5c83096lj3g4r0000gn/T//RtmpwSlW1s/filee0af4f9efac8