#+title: noa₂co₂
#+author: William Denton

There is as yet no machine-readable data file available that gives daily atmospheric CO₂ readings from any of the many monitoring stations around the globe.  Until there is, this fills in.

It scrapes the manually-entered data out of [[https://gml.noaa.gov/ccgg/trends/monthly.html][Recent Daily Average Mauna Loa CO₂]] that is maintained by the [[http://www.esrl.noaa.gov/][Earth System Research Laboratory]] (part of the US government's National Oceanic & Atmospheric Administration).  That data is added to a CSV file (of all recent readings) and a JSON file (of just the last valid reading, ignoring any NAs).

* How to use it

This requires [[https://www.ruby-lang.org/en/][Ruby]] and the [[http://bundler.io/][Bundler]] gem.

To install from Codeberg:

#+begin_src shell
git clone git@codeberg.org:wdenton/noa2co2.git
# or git clone https://codeberg.org/wdenton/noa2co2.git
cd noa2co2/
bundle install
#+end_src

To use:

#+begin_src shell
./noa₂co₂.rb
#+end_src

I use [[https://github.com/rbenv/rbenv][rbenv]] (installed with my [[https://github.com/wdenton/conforguration][Conforguration]] package) and use this for the cron job; sourcing ~.bashrc~ sets up the environment:

#+begin_example
30 9-11 * * *  source ~/.bashrc; cd ~/noa2co2/; ./noa₂co₂.rb; ./update_repo.sh
#+end_example

* Direct links to the data

+ [[https://raw.githubusercontent.com/wdenton/noa2co2/master/mauna-loa.csv][CSV of all recent data]]
+ [[https://raw.githubusercontent.com/wdenton/noa2co2/master/mauna-loa-latest.json][JSON file of just the last known reading]]

* License

GPL v3.  See COPYING.