< Ammonia - NH3 Organic volatile compounds - VOCs >

Associated topic: acidification, greenhouse effect, photochemical pollution

Emissions monitoring period: since 1960

Data source: CITEPA / SECTEN format - April 2017


Sources of the pollutant

Carbon monoxide (CO) is a colourless, odourless gas which forms mainly as a result of human activities. It is the result of incomplete fuel combustion, usually due to poor adjustment of the equipment (a problem that arises especially with small appliances). CO is also found in emissions from certain industrial processes (mineral agglomeration, steel manufacture, waste incineration), but also and especially in exhaust fumes from vehicles.


Effect of the pollutant

CO binds to the haemoglobin in the blood, for which it has an affinity 200 times greater than oxygen. The brain and heart are the organs most vulnerable to oxygen starvation. Breathing in CO causes headaches and vertigo and in high concentrations, causes nausea and vomiting. Prolonged exposure to high concentrations of CO in a confined area can cause fatal asphyxia.

From the point of view of the environment, CO contributes to acidification of the air, soils and watercourses, thus affecting ecosystems. It can contribute to the formation of tropospheric ozone, which is in the air we breathe. It can also be transformed by chemical reaction into CO2, which is one of the main greenhouse gases.


Classification of the sub-sectors with the highest emission levels* in 2015

Classification Sub-sectors Share of sub-sector in total national emissions in mainland France
1 Residential sector including: 42% including:
Combustion of heating appliances (boilers, inserts, closed and open fireplaces, stoves, etc.) 38%
Non road mobile machineries - Household and gardening 3.5%
Open burning of household garden wastes and other (vehicle burning, etc.) 0.5%
2 Ferrous metals smelting including: 30% including:
Pig iron tapping 9.5%
Basic oxygen furnace steel plant 6.7%
Sinter and pelletizing plant 6.1%
Gray iron foundries 5.1%
Blast furnace charging 2.4%
Electric furnace steel plant 0.2%
3 Gasoline-fuelled passenger cars 5.5%
4 French navigation (according to UNFCCC definitions) 3.3%
5 Two-wheeled vehicles 2.9%

*: one sector (out of six: energy transformation, manufacturing industry, residential/tertiary, agriculture/forestry, road transport and other transport) is broken down into sub-sectors.


Emissions and trends

Minimum observed: 2 994 kt in 2015
Maximum observed: 14 384 kt in 1973
Emissions in 2015: 2 994 kt
Trends 2015/1980: -77.7%
Trends 2015/1990: -71.3%
Trends 2015/maximum: -79.2%
Trends 2015/minimum

Measurement unit: kt (kilotonne)
Source CITEPA / SECTEN format – April 2017


Graph CO 17

Graph Legende sans UTCFv2

Source CITEPA / SECTEN format – April 2017

Tab CO 17

(*) Following UNECE/NEC definitions : emissions classified "except total" are not included, i.e. emissions from international maritime, emissions from domestic and international air transport cruise (≥ 1000 m), emissions from agriculture and forestry biogenic sources and emissions from non-anthropogenic sources.
(e) preliminary estimate



The breakdown of CO emissions varies depending on the decades considered. After a significant increase from 1960 to 1973, CO emissions have since declined overall.

These fluctuations are a result of... (to read more, consult the SECTEN report online via your login and password)

Data source: CITEPA / SECTEN format - April 2017

Open burning