LES CLÉS POUR COMPRENDRE
INSIDE CLIMATE CHANGE
Greenhouse gases, carbon offsetting, global warming: terms like these have become part of everyday language, but the physical mechanisms they refer to are complex and not always clearly understood.
CARBON, THE GREENHOUSE EFFECT AND CLIMATE
The greenhouse effect is a natural and even necessary phenomenon, by which some of the heat from the sun’s rays is retained by certain gases such as carbon dioxide (CO2) and methane. This helps the Earth maintain a habitable temperature for all its ecosystems. However, due to the massive production of CO2 resulting from human activity and population growth, this heat-trapping process has intensified, increasing our planet’s surface temperature. This is the main cause of climate change, which has led to a greater frequency of extreme and devastating environmental events, which include floods, storms, forest fires and droughts. Ultimately, the survival of the world’s ecosystems is at stake.
HUMAN ACTIVITY
CO2 EMISSIONS
AGGRAVATING FACTORS:artificial land cover, transportation and urban spread
OCEANS
MITIGATING FACTORS:renewable energies, recycling, non-motorized transportation...
PLANTS, FORESTS, TROPICAL FOREST
CO2 CAPTURE
MITIGATING FACTORS:carbon sinks, reforestation
THE CARBON CYCLE
Oceans and plants capture the carbon dioxide emitted by people and animals and by human activities, keeping the quantity of carbon at a stable level. This balance has been upset by the significant burning of fossil fuels (gas, oil and coal) by humans, combined with the spread of artificial land due to urban sprawl. This disruption can be slowed by increasing our use of renewable energy, recycling and non-motorized transportation, such as bicycles. We can also expand the Earth’s carbon absorption capacity by replanting forests and developing other carbon capture solutions.
CARBON NEUTRALITY
Carbon neutrality is achieved when the volume of CO2 emissions generated by an organization or region is balanced by an equivalent removal of carbon, whether through natural carbon sinks or industrial processes for carbon capture and reuse. This is different from carbon offsetting, in which the impact of fossil fuel emissions in one area is neutralized by financing new carbon sinks in another area (such as reforestation or carbon capture solutions).
Global CO2 e emissions by sector in 2018*
TRANSPORTATION (OF WHICH 45% FROMPASSENGER ROAD TRANSPORTATION) : 25%
ELECTRICITY PRODUCTION : 42%
ENERGY SECTOR (EXCLUDING ELECTRICITY) : 5%
TERTIARY SECTOR AND PUBLIC SERVICES : 3%
INDUSTRIAL ACTIVITIES AND CONSTRUCTION : 19%
RESIDENTIAL SECTOR : 6%
ROAD TRANSPORTATION
Transportation generates 25% of the world’s CO2 emissions, and 45% of these are from passenger road vehicles (11% of the total). As populations and people’s mobility needs continue to grow, the automotive industry’s role in greenhouse gas reduction has become an important one.
*source: IEA (INTERNATIONAL ENERGY AGENCY)