One could perhaps forgive the oilmen of the past. In their pursuit of black gold, they simply burnt off the natural gas that was extracted from the rocks alongside their precious oil. It was a time when Earth’s bounty seemed to expand without consequence in the face of human ingenuity and technological prowess. The incentive to invest in the infrastructure to capture the gas and bring it to market simply did not exist.

But that is no longer true. There is no justification for the large-scale burning off, or flaring, of natural gas by today’s oil industry, particularly in the United States, which is home to the most mature and advanced oil and gas industry in the world. Nearly one-third of the raw gas that is pumped out of the Bakken shale formation in North Dakota — a prime target of the new hydrofracturing and horizontal drilling technologies — is burned in situ.

True, flaring is preferable to venting gases such as methane, butane and propane directly into the atmosphere, but it still has a detrimental effect on both the global climate and the local air quality. And because companies are exempt from paying taxes or royalties on vented gas for the first year, at least, it is also bad for the public purse. As a result, the public gets a smaller return on the environmental price being paid to recover this oil — the inevitable impacts on public infrastructure, air and water resources, and on the landscape itself.

At a conservative estimate, this North Dakota flaring meant some 3.9 million tonnes of carbon dioxide were emitted last year, the equivalent of the annual emissions from 750,000 vehicles. Worse, research into flaring has begun to find evidence of potentially widespread methane leakage from shale operations, if not outright venting of the gas (see page 290). Methane is a powerful greenhouse gas, so the environmental price is likely to be even higher.

There are solutions. In North Dakota, the state could halt the practice of flaring except when necessary for safety reasons, or it could discourage companies from flaring by making them pay regular taxes and royalties on flared gas. This could delay the development of shale deposits, but that might be a good thing because it would give landowners and government agencies more time to work out how to regulate the environmental and social challenges that accompany energy booms such as shale exploitation. The companies have plenty of motivation to get shale resources out of the ground, and there can be little doubt that they would find ways to exploit the gas currently being flared, perhaps by exporting it. And methane emissions could be better controlled if the US Environmental Protection Agency regulated it as a greenhouse gas and instituted stricter rules across the oil and gas industry.

“The public gets a smaller return on the environmental price being paid to recover this oil.”

The US shale boom has been a boon to the struggling economy, providing jobs and government revenue in many far-flung places. The resulting oil production has allowed the United States to reduce foreign imports, and the plentiful shale-gas resources have lowered demand for coal, thereby curbing greenhouse-gas emissions in the power sector. But it will be up to scientists to pin down the full suite of impacts from the new oil and gas developments and to help policy-makers better understand the choices that they are making.

On 15 March, President Barack Obama proposed creating a US$2-billion Energy Security Trust to advance research and development into low-carbon transport alternatives. It would be funded over a decade by diverting a portion of the proceeds from federal oil and gas development, which are poised to grow thanks to the shale bonanza in North Dakota and beyond. It is a good idea as far as it goes, although once again it is hard not to despair at the general lack of ambition on climate issues in Washington. Improbable as it may be, a federal carbon tax would raise more money and would send an important signal to the energy industry that it needs to control its greenhouse-gas emissions.

The US economy is already benefiting from shale developments, and the country might even be able to lock in a one-time emissions reduction as part of a broader shift from coal to cleaner-burning natural gas in the coming years. A logical part of that equation is to kill off the current fashion for flares.