Society is unintentionally responsible for the slowdown of global warming several times over the last century, the Los Angeles Times reported.
Based on a study, the rate of global warming has decelerated in response to major world events such as the two world wars, the great depression, and most recently, a global ban on substances that reduce the ozone layer.
"Paradoxically, the recent decrease in warming, presented by global warming sceptics as proof that humankind cannot affect the climate system, is shown to have a direct human origin," said the study, published in the journal Nature Geoscience.
Researchers attribute this slowdown of global warming between the 1930s and the 1950s "to an unparalleled drop" in carbon dioxide emissions as financial challenges plagued nations during World War I, the Great Depression and World War I.
According to the study, the rate of global warming sped up again around 1960, a reflection of the sharp rise in carbon emissions from industrial activity in the booming post-war economy.
Researchers attribute the most recent slowdown, since the late 1990s, to the decline in emissions of chlorofluorocarbons, greenhouse gases that were discontinued under the 1989 Montreal Protocol.
According to the Los Angeles Times, the global treaty was not intended to fight climate change, but to protect the atmosphere's ozone layer.
"As a byproduct we got these reductions in warming," Francisco Estrada, an economist at the Center for Atmospheric Sciences at the National Autonomous University of Mexico, who conducted the statistical analysis with colleagues in the United States and the Netherlands, told the Los Angeles Times.
Grist reported that according to the Environmental Protection Agency, chlorofluorocarbons emissions are down 90 percent since the protocol was implemented in the late 80s.
The agency called this cutback "one of the largest reductions to date in global greenhouse gas emissions," which not only benefits the ozone layer, but the climate.
Without the international treaty, the Earth's temperature would have been 0.18 degrees warmer than it is today, according to the researchers. They found that slashing those emissions has been a major driver of the slowdown in global warming.
The slowdown can also be attributed to aerosols in the atmosphere and record heat uptake by the world's oceans, changing farm practices in Asia such as more efficient water use in rice cultivation, which cut emissions of methane, a potent greenhouse gas that is more effective at trapping heat than carbon dioxide, according to researchers.
Estrada told the Los Angeles Times the findings are encouraging because they show human intervention can ease climate change, even inadvertently.
"If things keep going the way they are, carbon dioxide emissions will completely erase this slowdown in warming," Estrada said. "This might be only a temporary relief."
Estrada said these revelations should not be a reason for complacency when it comes to restricting greenhouse gas levels.
