Methane levels have more than doubled over the last 150 years because of human activities like fossil fuel use and intensive farming. Before the Industrial Revolution, the atmospheric concentration of methane was maintained in a safe range by natural sinks. But for a long time now human activities have been creating methane emissions much more rapidly than the Earth can remove them, increasing global methane levels. During the last 800,000 years, methane concentrations naturally varied between 350-800 ppb but since the Industrial Revolution, methane levels have become much higher and are now 2.5 times larger. Due to human activities, CH4concentrations increased sharply during most of the 20th century and are now more than two-and-a-half times pre-industrial levels.
In recent decades, the rate of increase has slowed considerably on a global scale.
In recent decades, the rate of increase has slowed considerably on a global scale.
In the United States, based off emission records, the reports of methane emissions have been declining over the last decade.