The largest polluters in the world are a diverse group of industries. They include oil and gas, fashion, mining, construction, transportation, and energy. Their contribution to global greenhouse gas emissions has reached more than 15 billion tons per year. These industries are primarily responsible for contributing to air and water pollution, which can lead to health problems and even deaths.
Some of the companies on the list are private companies and others are state-owned. They are either multinational firms, such as Exxon or BP, or they are local businesses, such as the state-owned Chevron. Both have been accused of not taking sufficient action to combat global warming.
Despite this, the top 20 fossil fuel companies have contributed nearly three-fifths of all global greenhouse gas emissions since 1965. Most of these companies are investor-owned, but 12 of the top 20 are state-owned.
These companies produce a large share of their emissions directly, including carbon dioxide emissions that come from burning fossil fuels for energy. Other contributors are chemical reactions, such as generating cement, or from leaks from natural gas and petroleum systems. A third of these emissions are indirect. That means that they are produced by burning fossil fuel at power plants.
Another factor that influences the list is water pollution. One of the biggest culprits is the US military. Compared to medium-sized countries, the military consumes more liquid fuels, which increases the amount of climate-changing gases it releases.
While the United States has been the biggest global emitter of carbon dioxide for over two centuries, it has fallen into second place in recent years. The country's emissions increased slightly last year. However, they are still down from their 2005 levels.
China, however, has become the largest polluter on an absolute basis. In 2012, China pumped 9.8 billion tons of CO2 into the atmosphere. Its five provinces emitted more than any other country. Despite this, it only accounted for less than a sixth of the excess carbon dioxide in the atmosphere.
Russia is the fourth biggest polluter. Russia's carbon dioxide emissions plunged after the collapse of the Soviet smokestack industries. Since the mid-1990s, it has made significant efforts to fight climate change. The country has pledged to cut methane emissions and conserve forests.
India, on the other hand, ranks among the top 10 polluters on a per capita basis. Although its population is larger than the United States', its contribution is relatively small. It has high rates of deforestation, which has negative long-term consequences.
As the climate crisis continues to worsen, the world faces an urgent need for tougher policies. The United Nations has warned that global temperature rise needs to be limited to 1.5C above pre-industrial levels. There is now a 12-year window to take steps to avoid the worst consequences of runaway global heating.
The world's leading polluters need to cut their greenhouse gas emissions. The list is designed to hold these companies accountable. To do this, it has contacted twenty of the biggest fossil fuel companies and asked them to respond.