Carbon emissions are a leading human-caused greenhouse gas, which can linger in the atmosphere for thousands of years. These emissions are the result of burning fossil fuels (coal, oil, natural gas) and land-use changes that release carbon dioxide into the air.
Emissions rise and fall depending on the economy, weather conditions, and fuel prices. For example, if an organization adds another facility or suppliers, their overall emissions might increase even if they’ve done efficiency projects. This is because the organization might be running more often, so it’s releasing more CO2 per day than before.
Prosperity is a primary driver of CO2 emissions, but the policies and technology choices a country makes also make a difference. For example, some European countries — including France, Portugal, and Germany — have lower CO2 emissions than their neighbors with similar living standards. This is because these countries rely more on renewable energy sources and less on coal.
In 2024, CO2 emissions increased worldwide because of a range of factors. A series of extreme temperatures led to higher fossil fuel use in power generation, while a rebound in travel following the COVID-19 pandemic drove higher aviation emissions.
In addition to reducing carbon emissions, high levels of CO2 can cause other environmental problems, such as acidification of oceans and freshwater systems, eutrophication, and depletion of soil nutrients. These effects can further motivate action on lowering GHG emissions.