Environmental impact

Like any human activity, using ctools will have an environmental impact. This includes for example the greenhouse gas emissions related to electricity production that is needed to run your computer or data centre. It includes as well the environmental footprint of your computing hardware, the power and material behind your internet connection, your storage array, and even the footprint of the personnel that eventually runs your data centre.

As ctools user you should be aware of this footprint, and you should aim to reduce it as much as possible.

To guide you in this endeavor, all ctools and cscripts inform you at the end of the log file about the estimated carbon footprint of your computations:

2022-02-18T22:33:26: Application "ctlike" terminated after 3910.0 wall clock seconds, consuming 3881.18 seconds of CPU time and generating a carbon footprint of 3.81083 g eCO2.

This estimate is based on the study of Berthoud et al. (2020) who assessed the carbon footprint of the DAHU cluster of the UMS GRICAD (Grenoble, France) in 2019. Their study included

• server fabrication

• server environment

• server usage (electricity)

• travelling of personnel in the context of their work

• travelling of personnel from home to office

• personnel equipment

• personnel energy

Berthoud et al. (2020) found that, per CPU hour, the footprint of the GRICAD data centre was 2.43 g CO2e (equivalent CO2 emissions) due to electricity use and 2.25 g CO2e due to the data centre environment, hardware fabrication and the personnel. For their study a carbon intensity of 108 g eCO2 / kWh for greenhouse gas emission due to electricity generation was assumed.

The latter varies substantially between countries. While the current electricity mix in France has a (rounded) carbon intensity of 60 g eCO2 / kWh, values go through 240 g eCO2 / kWh (Spain), 410 g eCO2 / kWh (Italy), 460 g eCO2 / kWh (Germany), 520 g eCO2 / kWh (USA), up to 840 g eCO2 / kWh (Australia). So eventually, you should think about doing your computations in a country with a low carbon intensity, or make sure that your data centre is running on a low carbon energy source.

ctools will determine in which country your code is executed and fetch the appropriate carbon intensity for the general energy mix in this country to estimate the carbon footprint of your computations. The estimate is done using

\[{\rm Carbon\,\,footprint} = \left( 2.25 + 2.43 \frac{\rm CI}{108} \right) \times {\rm CPU\,\,hours}\]

where \({\rm CI}\) is the carbon intensity of the electricity mix in your country in units of g eCO2 / kWh, \({\rm CPU\,\,hours}\) is the number of CPU hours your computation took, and \({\rm Carbon\,\,footprint}\) is the carbon footprint in g eCO2.

The carbon footprint of all ctools and cscript runs are stored in an ASCII file that you will find in a folder under your home directory, named .gamma/statistics.csv. This file is regularly scanned and purged by the GammaLib daemon that creates the high-level statistics file .gamma/statistics.xml that is in the same folder. You may display the content of this file using the csfootprint script:

$ csfootprint debug=yes
Start time for report (UTC string, JD, MJD or MET in seconds) [NONE]
Stop time for report (UTC string, JD, MJD or MET in seconds) [NONE]
Output graphics file (NONE if no graphics should be generated) [NONE]
...
2022-03-11T15:12:58: +===================+
2022-03-11T15:12:58: | Global statistics |
2022-03-11T15:12:58: +===================+
2022-03-11T15:12:58:  Creation date .............: 2022-02-21T10:55:46
2022-03-11T15:12:58:  Last statistics update ....: 2022-03-11T15:11:43
2022-03-11T15:12:58:  Statistics date interval ..: 2022-02-21T09:55:58 - 2022-03-11T15:08:00
2022-03-11T15:12:58:  Used date interval ........: 2022-02-21T09:55:58 - 2022-03-11T15:08:00
2022-03-11T15:12:58:  Duration of used interval .: 437.2 hours
2022-03-11T15:12:58:  Total number of ctool runs : 61250
2022-03-11T15:12:58:  Total wall clock time .....: 9418.0 hours
2022-03-11T15:12:58:  Total CPU time ............: 9418.2 hours
2022-03-11T15:12:58:  Average CPU load ..........: 100.0 %
2022-03-11T15:12:58:  Total carbon footprint ....: 33.3 kg CO2e
2022-03-11T15:12:58:   due to power consumption .: 12.1 kg CO2e (57.1 g CO2e / kWh)
2022-03-11T15:12:58:   due to infrastructure ....: 21.2 kg CO2e
2022-03-11T15:12:58:  Average carbon intensity ..: 3.5 g CO2e / CPU hour
2022-03-11T15:12:58:  Average daily footprint ...: 1.8 kg CO2e / day
2022-03-11T15:12:58:  Expected annual footprint .: 667.5 kg CO2e / year
2022-03-11T15:12:58:
2022-03-11T15:12:58: +==================+
2022-03-11T15:12:58: | Daily statistics |
2022-03-11T15:12:58: +==================+
2022-03-11T15:12:58: === Carbon footprint ===
2022-03-11T15:12:58:  2022-02-21 ................: 3.6 g CO2e
2022-03-11T15:12:58:  2022-02-22 ................: 239.6 g CO2e
2022-03-11T15:12:58:  2022-02-23 ................: 1.4 kg CO2e
2022-03-11T15:12:58:  2022-02-24 ................: 2.1 kg CO2e
2022-03-11T15:12:58:  2022-02-25 ................: 2.2 kg CO2e
2022-03-11T15:12:58:  2022-02-26 ................: 2.6 kg CO2e
2022-03-11T15:12:58:  2022-02-27 ................: 2.6 kg CO2e
2022-03-11T15:12:58:  2022-02-28 ................: 2.2 kg CO2e
2022-03-11T15:12:58:  2022-03-01 ................: 1.9 kg CO2e
2022-03-11T15:12:58:  2022-03-02 ................: 1.2 kg CO2e
2022-03-11T15:12:58:  2022-03-03 ................: 853.8 g CO2e
2022-03-11T15:12:58:  2022-03-04 ................: 723.2 g CO2e
2022-03-11T15:12:58:  2022-03-05 ................: 372.5 g CO2e
2022-03-11T15:12:58:  2022-03-06 ................: 300.7 g CO2e
2022-03-11T15:12:58:  2022-03-08 ................: 1.9 kg CO2e
2022-03-11T15:12:58:  2022-03-09 ................: 4.1 kg CO2e
2022-03-11T15:12:58:  2022-03-10 ................: 6.0 kg CO2e
2022-03-11T15:12:58:  2022-03-11 ................: 2.8 kg CO2e
2022-03-11T15:12:58: === ctools or cscript calls ===
2022-03-11T15:12:58:  2022-02-21 ................: 52
2022-03-11T15:12:58:  2022-02-22 ................: 545
2022-03-11T15:12:58:  2022-02-23 ................: 2372
2022-03-11T15:12:58:  2022-02-24 ................: 3097
2022-03-11T15:12:58:  2022-02-25 ................: 3520
2022-03-11T15:12:58:  2022-02-26 ................: 3813
2022-03-11T15:12:58:  2022-02-27 ................: 3606
2022-03-11T15:12:58:  2022-02-28 ................: 2985
2022-03-11T15:12:58:  2022-03-01 ................: 2412
2022-03-11T15:12:58:  2022-03-02 ................: 1322
2022-03-11T15:12:58:  2022-03-03 ................: 911
2022-03-11T15:12:58:  2022-03-04 ................: 747
2022-03-11T15:12:58:  2022-03-05 ................: 356
2022-03-11T15:12:58:  2022-03-06 ................: 284
2022-03-11T15:12:58:  2022-03-08 ................: 5850
2022-03-11T15:12:58:  2022-03-09 ................: 11850
2022-03-11T15:12:58:  2022-03-10 ................: 13015
2022-03-11T15:12:58:  2022-03-11 ................: 4513
2022-03-11T15:12:58: === Used wall clock time ===
2022-03-11T15:12:58:  2022-02-21 ................: 51.2 minutes
2022-03-11T15:12:58:  2022-02-22 ................: 67.8 hours
2022-03-11T15:12:58:  2022-02-23 ................: 400.1 hours
2022-03-11T15:12:58:  2022-02-24 ................: 584.9 hours
2022-03-11T15:12:58:  2022-02-25 ................: 625.2 hours
2022-03-11T15:12:58:  2022-02-26 ................: 732.0 hours
2022-03-11T15:12:58:  2022-02-27 ................: 723.2 hours
2022-03-11T15:12:58:  2022-02-28 ................: 621.0 hours
2022-03-11T15:12:58:  2022-03-01 ................: 524.5 hours
2022-03-11T15:12:58:  2022-03-02 ................: 329.3 hours
2022-03-11T15:12:58:  2022-03-03 ................: 241.6 hours
2022-03-11T15:12:58:  2022-03-04 ................: 204.6 hours
2022-03-11T15:12:58:  2022-03-05 ................: 105.4 hours
2022-03-11T15:12:58:  2022-03-06 ................: 85.1 hours
2022-03-11T15:12:58:  2022-03-08 ................: 535.9 hours
2022-03-11T15:12:58:  2022-03-09 ................: 1159.5 hours
2022-03-11T15:12:58:  2022-03-10 ................: 1693.2 hours
2022-03-11T15:12:58:  2022-03-11 ................: 783.9 hours
2022-03-11T15:12:58: === Used CPU time ===
2022-03-11T15:12:58:  2022-02-21 ................: 1.0 hours
2022-03-11T15:12:58:  2022-02-22 ................: 67.8 hours
2022-03-11T15:12:58:  2022-02-23 ................: 400.1 hours
2022-03-11T15:12:58:  2022-02-24 ................: 584.9 hours
2022-03-11T15:12:58:  2022-02-25 ................: 625.2 hours
2022-03-11T15:12:58:  2022-02-26 ................: 732.0 hours
2022-03-11T15:12:58:  2022-02-27 ................: 723.2 hours
2022-03-11T15:12:58:  2022-02-28 ................: 621.0 hours
2022-03-11T15:12:58:  2022-03-01 ................: 524.5 hours
2022-03-11T15:12:58:  2022-03-02 ................: 329.3 hours
2022-03-11T15:12:58:  2022-03-03 ................: 241.6 hours
2022-03-11T15:12:58:  2022-03-04 ................: 204.6 hours
2022-03-11T15:12:58:  2022-03-05 ................: 105.4 hours
2022-03-11T15:12:58:  2022-03-06 ................: 85.1 hours
2022-03-11T15:12:58:  2022-03-08 ................: 535.9 hours
2022-03-11T15:12:58:  2022-03-09 ................: 1159.5 hours
2022-03-11T15:12:58:  2022-03-10 ................: 1693.2 hours
2022-03-11T15:12:58:  2022-03-11 ................: 783.9 hours
2022-03-11T15:12:58:
2022-03-11T15:12:58: +================================+
2022-03-11T15:12:58: | ctools and cscripts statistics |
2022-03-11T15:12:58: +================================+
2022-03-11T15:12:58: === Carbon footprint ===
2022-03-11T15:12:58:  comobsback ................: 13.5 kg CO2e
2022-03-11T15:12:58:  comlixfit .................: 8.1 kg CO2e
2022-03-11T15:12:58:  comobsmodel ...............: 5.2 kg CO2e
2022-03-11T15:12:58:  comobsres .................: 5.2 kg CO2e
2022-03-11T15:12:58:  comlixmap .................: 364.9 g CO2e
2022-03-11T15:12:58:  ctlike ....................: 319.7 g CO2e
2022-03-11T15:12:58:  cttsmap ...................: 205.8 g CO2e
2022-03-11T15:12:58:  comobsbin .................: 165.1 g CO2e
2022-03-11T15:12:58:  csspec ....................: 130.7 g CO2e
2022-03-11T15:12:58:  comobssim .................: 116.1 g CO2e
2022-03-11T15:12:58:  ... (list truncated after 10 entries) ...
2022-03-11T15:12:58: === ctools or cscript calls ===
2022-03-11T15:12:58:  comobsbin .................: 15352
2022-03-11T15:12:58:  comobsmodel ...............: 14856
2022-03-11T15:12:58:  comobsback ................: 11439
2022-03-11T15:12:58:  comobsres .................: 11428
2022-03-11T15:12:58:  comlixfit .................: 3525
2022-03-11T15:12:58:  comobssim .................: 3458
2022-03-11T15:12:58:  ctlike ....................: 1048
2022-03-11T15:12:58:  cscaldb ...................: 63
2022-03-11T15:12:58:  comobsselect ..............: 20
2022-03-11T15:12:58:  csfootprint ...............: 17
2022-03-11T15:12:58:  ... (list truncated after 10 entries) ...
2022-03-11T15:12:58: === Used wall clock time ===
2022-03-11T15:12:58:  comobsback ................: 3810.6 hours
2022-03-11T15:12:58:  comlixfit .................: 2282.3 hours
2022-03-11T15:12:58:  comobsmodel ...............: 1480.6 hours
2022-03-11T15:12:58:  comobsres .................: 1471.7 hours
2022-03-11T15:12:58:  comlixmap .................: 103.2 hours
2022-03-11T15:12:58:  ctlike ....................: 90.4 hours
2022-03-11T15:12:58:  cttsmap ...................: 58.2 hours
2022-03-11T15:12:58:  comobsbin .................: 46.7 hours
2022-03-11T15:12:58:  csspec ....................: 37.0 hours
2022-03-11T15:12:58:  comobssim .................: 32.9 hours
2022-03-11T15:12:58:  ... (list truncated after 10 entries) ...
2022-03-11T15:12:58: === Used CPU time ===
2022-03-11T15:12:58:  comobsback ................: 3810.6 hours
2022-03-11T15:12:58:  comlixfit .................: 2282.3 hours
2022-03-11T15:12:58:  comobsmodel ...............: 1480.7 hours
2022-03-11T15:12:58:  comobsres .................: 1471.7 hours
2022-03-11T15:12:58:  comlixmap .................: 103.2 hours
2022-03-11T15:12:58:  ctlike ....................: 90.4 hours
2022-03-11T15:12:58:  cttsmap ...................: 58.2 hours
2022-03-11T15:12:58:  comobsbin .................: 46.7 hours
2022-03-11T15:12:58:  csspec ....................: 37.0 hours
2022-03-11T15:12:58:  comobssim .................: 32.9 hours
2022-03-11T15:12:58:  ... (list truncated after 10 entries) ...

The csfootprint script optionally generates a graphical representation of the carbon footprint if a file name other than NONE is provided for the output graphics file. The matplotlib Python module is required to produce the representation. If the module is not installed the graphical output will be skipped. Below is an example of graphics produced by csfootprint:

Carbon footprint statistics generated by csfootprint