(CNN) — China and America top the list of the world’s hottest emitters of greenhouse gases, so any attempt to tackle the climate crisis will need significant emissions cuts from these two powerful nations.
China’s emissions are more than twice that of the United States, but historically, the United States has emitted more emissions than any other country in the world. The list includes other countries such as India, the European Union, Indonesia, Russia, Japan, Brazil, Iran, and Saudi Arabia.
There are many factors to consider when judging a country’s climate credentials, and with leaders meeting in Glasgow, Scotland for COP26 from Sunday, the plans of the US and China will be in the spotlight.
In 2006, China overtook the United States as the world’s largest emitter of carbon dioxide – the most abundant greenhouse gas in the atmosphere.
In 2019, the last year before the epidemic, China’s greenhouse gas emissions were nearly 2.5 times that of the United States, and more than all of the developed world combined, according to an analysis from the Rhodium Group.
In terms of carbon dioxide equivalent – a way to measure all greenhouse gases as if they were carbon dioxide – China released 14.1 billion metric tons in 2019. That’s more than a quarter of the world’s total emissions.
By contrast, the United States was responsible for 5.7 billion tons, 11% of total emissions, followed by India (6.6%) and the European Union (6.4%).
When scientists measure greenhouse gas emissions, they look at the total emissions a country puts into the air on its land each year. These emissions come from anything that runs on fossil fuels, including driving gasoline cars, aviation, heating and lighting buildings powered by coal, natural gas, or oil, as well as from the energy industry. Other sources, such as emissions from deforestation, are also included.