Carbon dioxide (CO2) is an odorless gas that is highly important to life on Earth. As a greenhouse gas, an excessive concentration of CO2 can disrupt the natural regulation of temperature in the atmosphere and lead to global warming.
The concentration of CO2 has especially increased as a result of the Industrial Revolution and exponential growth in manufacturing activities around the world. Deforestation, agriculture, and fossil fuel use are the primary sources of CO2.
According to the most recent data from theGlobal Carbon Atlas, the top five countries that have produced in aggregate the most CO2 since the Industrial Revolution are the United States, China, Russia, Germany, and the United Kingdom. In 2020, the largest emitters were in China, the U.S., India, Russia, and Japan.
Key Takeaways
- Carbon dioxide, which is a greenhouse gas, has become a major concern as climate change becomes a bigger issue.
- The top five CO2-producing nations in 2021 were China, the United States, India, Russia, and Japan.
- The U.S. has the bulk of its emissions coming from the transportation sector; burning fossil fuel for cars, ships, planes, etc.
1. China
China is the largest emitter of carbon dioxide gas in the world, with 11,336 million metric tons emitted in 2021. The primary source of CO2 emissions in China is fossil fuels, most notably those that burn coal. About 58% of the total energy generated by China in 2021 came from coal alone, and because coal is rich in carbon, burning it in China's power and industrial plants and boilers releases large amounts of CO2 into the atmosphere.
Also, China is one of the largest importers of oil, which contributes to large CO2 emissions through the country's use of motor vehicles. China plans to reduce its dependence on coal and decrease overall pollution in large cities in the future by generating more electricity using nuclear, renewable energy sources, and natural gas.
The $1 trillion Infrastructure Investment and Jobs Act was signed into law byPresident Joe Biden on Nov. 15, 2021.
This bill covers funding to improve infrastructure across the U.S. and funds include $7.5 billion for a nationwide network of electric vehicle charging stations and $65 billion to update power lines, prevent hacking of the power grid, and provide clean energy. All of these areas have the potential to improve CO2 emissions in the United States.
2. The United States
The U.S. is the second-largest emitter of CO2, with 5,032 million metric tons of total carbon dioxide emissions in 2021. The largest sources of CO2 emissions in the U.S. came from transportation, electric power, and industry in 2021. Even though the U.S. government undertook significant efforts to reduce the reliance on coal for electricity generation, the country remains a major producer of crude oil.
The U.S. economy is also heavily reliant on the transportation sector, which burns petroleum for trucks, ships, trains, and planes. U.S. consumers especially depend on their cars as their primary means of transportation, and this also contributes to the CO2 footprint through gasoline and diesel.
Another large contributor to CO2 emissions in the U.S. is industry, which burns fossil fuels for energy. Also, the U.S. chemical sector uses various chemical reactions necessary to produce goods from raw materials, which in the process, emit CO2.
3. India
India is the third-largest CO2 emitter, with 2,674 million metric tons of total carbon dioxide emissions produced in 2021. Coal is the main energy source for India, supplying about 44% of the energy in the country. Petroleum and other liquids provided about 24%.
Natural gas accounts for only 6% of India's energy consumption. However, the country plans to increase the natural gas market share to 15% by 2030 to reduce air pollution and use cleaner-burning fuels.
4. Russia
Russia is the fourth-largest contributor to CO2 emissions in the world, emitting 1,712 million metric tons in 2021. Russia has one of the largest natural gas deposits in the world, and natural gas is the primary source of energy and power generation in the country.
Coal, which is widely used in chemical and other basic material industries and for power generation in Russia, is also a major contributor to Russia's CO2 emissions. Russia has also been a large supplier of natural gas to other countries, primarily in Europe. However, European countries have been cutting back on Russian natural gas due to the country's invasion of Ukraine, and Russia is also cutting back on its supply of gas to Europe.
5. Japan
Japan is the fifth-largest producer of CO2 emissions, with 1,602 million metric tons in 2021. Japan's energy fuel mix changed after the 2011 nuclear accident at f*ckushima. Oil is the largest source of energy in Japan, with its total share of energy consumption being 38% in 2021, which is the latest figure available.
Coal still makes up a large share of energy consumption in Japan: 25%. Nuclear gas is becoming more prominent in Japan after the nuclear disaster and now accounts for 23% of energy consumption as of 2021. The country's energy plan from 2018 has the goal of increasing nuclear-fired power production by 2030 to reduce the dependency on hydrocarbon fuel imports.
Which Countries Have Produced the Most Carbon Dioxide Emissions?
The countries that have produced the most carbon dioxide emissions since 1750 have been the United States, China, Russia, Germany, the U.S., and Japan.
What Is the Main Source of CO2 Emissions?
Burning coal is the most significant contributor to anthropogenic CO2 emissions. Across all fossil fuels, coal is the most carbon-intensive. Given how inexpensive and ubiquitous a source of energy coal is, it has powered electricity grids for decades worldwide.
Why Are China's Emissions So High?
As the world's second-largest manufacturer, much of China's industrial production is powered by coal. Rapid urbanization has also intensified the country's CO2 emissions. Cement and steel production, which are both required for infrastructure, produce significant amounts of C02. Half of the world's steel is manufactured in China.
The Bottom Line
Carbon dioxide is the main greenhouse gas emitted by humans through different things like burning fossil fuels, deforestation, and (rising) industrial activities. The countries that are responsible for emitting the most CO2 in the world include the most advanced, including the U.S. and Japan, and some of the fastest-growing economies—notably, China, India, and Russia. While rising CO2 levels are a cause for concern, this gas does serve a purpose. It helps keep the Earth's temperature above freezing and helps lower pH levels in the world's oceans.
Correction―Oct. 10, 2022: A previous version of this article incorrectly stated the timeframe under consideration and referred to metric tons rather than millions of metric tons (megatonnes).
