The concentration of carbon dioxide in Earth’s atmosphere has risen significantly over the past century, mostly because of human activities. This rise in atmospheric CO2 levels, referred to as “CO2 pollution”, has caused climate change that can trigger extreme weather events and damage ecosystems and habitats.
The carbon dioxide in coal, oil and natural gas was originally produced by plants during the course of photosynthesis. When these fossil fuels are burned, they release CO2 back into the atmosphere, which then enters the global air system. Eventually, the CO2 is taken up by the oceans and stored there for thousands of years. This long term storage can’t be eliminated, but human activity can reduce the amount of CO2 emitted.
There are four main types of industrial processes that produce significant amounts of CO2: fossil fuel combustion, cement production, iron and steel manufacturing, and chemical production. The electric power sector produces the most CO2 in the United States, primarily from the combustion of fossil fuels. The United States’ CO2 emissions are also impacted by the country’s electricity mix, which can influence how much is generated from fossil fuels and how many emissions are associated with the production of energy.
As you might expect, there is a strong relationship between a country’s GDP and its per capita CO2 emissions. However, there is a great deal of variation among countries with similar standards of living. For example, some European countries have lower emissions than their neighbors with comparable economies because they produce a greater share of their electricity from renewable or nuclear sources.