It’s been a talking point for boosters of the shale gas rush for years: as fracking spread across the country and the supply glut drove prices down, utilities have been shuttering dirty coal plants and burning natural gas instead – meaning that America’s carbon dioxide (CO2) emissions dropped sharply. Fracking, the argument went, is actually good for the environment because it’s good for the climate.

“The boom in American natural-gas production is doing what international negotiations and legislation couldn’t: reducing U.S. carbon-dioxide pollution,” Bloomberg reported in 2012.

“While other factors, including a sluggish U.S. economy and increasing energy efficiency, have contributed to the decline in carbon emissions from factories, automobiles and power plants, many experts believe the switch from coal to natural gas for electricity generation has been the biggest factor,” said the Wall Street Journal in April 2013.

“In these last years, the natural gas revolution, shall we say, has been a major contributor to reducing carbon emissions,” the Obama administration’s Department of Energy Secretary Ernest Moniz said at Columbia University on Aug. 26, 2013, as he described the President’s goals for reducing carbon emissions. “We are about halfway there, and about half of that is because of the substitution of natural gas for coal in the power sector, essentially driven by market forces.”

But, it turns out, correlation is not the same thing as causation. And while the drop in emissions happened at roughly the same time as the fracking rush spread, shale gas had relatively little to do with the drop in carbon emissions, according to a scientific paper published today in the journal Nature Communications.

“Before 2007, rising emissions were primarily driven by economic growth,” ecological economist Dr. Klaus Hubacek and his fellow researchers wrote. “After 2007, decreasing emissions were largely a result of economic recession with changes in fuel mix (for example, substitution of natural gas for coal) playing a comparatively minor role.”

In fact, 83 percent of the drop in emissions from 2007 to 2009 came as a result of the economic collapse and the resulting drop in consumption of goods and services.

And in more recent years, other related factors helped keep U.S. carbon emissions from rising: an unusually warm winter in 2012, high gasoline prices that discouraged consumption and the adoption of energy-efficient technologies by manufacturers.

In other words, what worked was cutting consumption and being more efficient – not fracking.

Only 17 percent of the drop from 2007 to 2009 came from what the researchers called “changes in the fuel mix” – a shift away from notoriously carbon intensive coal-fired power plants, for example. But it’s worth noting that renewable energy sources were climbing as well over that time. The amount of electricity produced by wind and solar power in the US has spiked nearly ten-fold from 2005 to 2013, and as of 2013 contributed 4.5 percent of total American electricity generation.

And of course, while burning natural gas produces about 55 percent as much carbon as an equivalent amount of coal, natural gas also has another major greenhouse gas problem: methane. Methane, the key ingredient that natural gas is made of, is one of the most potent greenhouse gasses in our atmosphere, able to warm the climate 84 times more than an equal amount of CO2 in the first couple of decades after it reaches the atmosphere.

And even while U.S. CO2 emission rates have been falling – in other words, carbon dioxide is pouring into the atmosphere at a slower speed – all that pollution still adds up fast. The total amount of greenhouse gasses in the atmosphere has continued to climb sharply, according to a report issued in the Bulletin of the American Meteorological Society on July 16.

Last year was the warmest year on record, the State of the Climate 2014 report concluded – and both methane and CO2 levels have kept climbing worldwide, despite the recession.

“Major greenhouse gas concentrations, including carbon dioxide, methane and nitrous oxide, continued to rise during 2014, once again reaching historic high values,” the National Oceanic and Atmospheric Administration said as the State of the Climate report was released. “Atmospheric CO2 concentrations increased by 1.9 ppm in 2014, reaching a global average of 397.2 ppm for the year. This compares with a global average of 354.0 in 1990 when this report was first published just 25 years ago.”

Despite the risks, governments have continued to funnel resources to the fossil fuel industries – not only coal, but also oil and natural gas. Fossil fuel subsidies will add up to over $5.3 trillion dollars in 2015, the International Monetary Fund estimated in a report released in May.  Subsidies for renewable energy add up to only $120 billion, the IMF concluded.

Even with this handicap, the renewable energy industry has continued to grow – and some environmentalist argue that it’s possible to keep emissions low while creating jobs.

“Significant progress has already been made in overcoming the hitherto conventional wisdom that taking steps to cut [greenhouse gasses] is incompatible with economic growth,” said Yvo de Boer, Director-General of the Global Green Growth Institute, which released a report last month on jobs in the renewable energy industry. “[E]mployment and development result from sustainable, green growth.”

Photo Credit: “View of coal power plant against sun with several chimneys and huge fumes” via Shutterstock.