Natural gas has long been seen as a stepping stone for a world looking to replace coal with renewable energy. As solar arrays and wind farms are being built, the theory goes, natural gas can be a substitute for “dirtier” fuels like coal and, in some cases, oil.
But research indicates that emissions of methane, the main constituent of natural gas, that occur during its extraction and transportation make natural gas not as climate-friendly as previously thought.
By 2030, the world will need to cut greenhouse gas emissions by more than 40 percent if it is to meet the most ambitious goals of the Paris Agreement, according to the Intergovernmental Panel on Climate Change, a body of the United Nations. We spoke to Mark Radka, Head of the Energy and Climate Branch of the United Nations Environment Program (UNEP), about the role natural gas should play in reducing emissions and transitioning to a future of renewable energies.
Is natural gas a cleaner alternative to coal or oil in terms of emissions?
Mark Radka (MR): Natural gas is a cleaner fuel in the sense that its combustion produces fewer conventional air pollutants, such as sulfur dioxide and particulate matter, than burning coal or oil. How much more depends on the characteristics of the fuel, the combustion technology, the proper maintenance and operation of the equipment and other factors. In general, burning natural gas also produces less carbon dioxide per unit of energy, about half as much as the best coal technology, and by that measure is better from a climate perspective.
Researchers have discovered that massive amounts of methanea powerful greenhouse gas, leaks from natural gas facilities around the world. Does this call into question the idea that natural gas is cleaner than other fossil fuels?
MR: Recent scientific measurement campaigns, some of them supported by UNEP, have shown that methane emissions from oil and gas operations are much higher than previously estimated. Methane is a potent greenhouse gas, about 84 times more potent than carbon dioxide measured over a 20-year period, so any emissions undermine its credentials as the best fossil fuel. So “cleaner” probably isn’t the best word to describe natural gas. But as long as methane emissions are managed well, it is not as problematic in terms of global warming as coal or oil.
Is it unrealistic to expect fossil fuel companies to control methane leaks?
MR: I think it’s unrealistic to expect all fossil fuel companies to police themselves, so regulations that limit emissions levels and good law enforcement are certainly crucial. But many companies are willing to act even without regulatory pressure. We are working with many companies that have committed to setting methane reduction targets by 2025, measuring their methane emissions, taking action to reduce them and reporting the results. Detection technologies are improving and UNEP is working in parallel with partners to provide open and transparent information on emissions. Methane leaks are costly, so from an economic perspective companies have an interest in reducing leaks.
Since the war in Ukraine began, construction has begun approx 20 liquefied natural gas receivers terminals around the world, including in Germany and China, resulting in an increasing percentage of methane transported by sea. Are ships more prone to methane leaks than pipelines?
MR: The direct answer is that this is currently unknown, but in principle it can be known. There is a lack of empirically verified measurement data across the natural gas industry, which is precisely why UNEP started the International Methane Emissions Observatory (IMEO). Most methane data are based on estimates of emission factors, rather than actual measurements. UNEP’s goal with IMEO is to provide real answers to these types of questions.
UNEP Emissions Gap Report says we need to cut greenhouse gas emissions by up to 45 percent by 2030 to avoid a full-blown climate crisis. Is natural gas a good bridge fuel for countries looking to transition from coal and oil?
MR: Everything depends on the speed of the transition, which science tells us must be fast to avoid the worst consequences of climate change. A long or slow transition away from other fossil fuels and requiring a lot of investment in gas infrastructure would be a bad bridge. In many countries natural gas has already replaced coal as the fuel of choice for electricity production, with benefits for climate and air quality. The rapidly decreasing cost of solar, wind and other renewable energy technologies is making them an even better alternative to gas in more and more places. Where gas has a special role to play in the energy transition is as a support to a renewables-based electricity system, as gas boilers can fire up almost instantly while starting up a coal-fired power plant takes much longer. There is a lot of research and deployment of energy storage technologies, so this role of gas will diminish.
With renewable energy costs at record lows, why are some countries still choosing to invest in natural gas? What are the biggest issues when it comes to the transition to wind and solar?
MR: It is important to remember that with today’s technologies not all energy sources are interchangeable. Aviation and shipping, for example, are still largely dependent on fossil fuels, as are some so-called hard-to-reduce industries, such as iron smelting. Much research and development is taking place and much more is needed in areas such as storage, but we are not yet at the stage where all fossil fuels can be replaced by renewable energy. The world is becoming increasingly electrified and wind and solar energy will become increasingly important, especially in places where renewable energy resources (sun and wind) are abundant. It is important to note that we are in the early stages of an energy transition that is unlike anything the world has ever attempted in terms of speed and complexity. It is a transition, however, and any transition takes time and persistence. That said, we need to move quickly.
Are there better alternatives to natural gas for countries that cannot invest in wind or solar?
MR: Every country and every person needs to think more critically about energy efficiency. We never value energy for its own sake; instead, we value the many services that energy makes possible. I’m talking here about communication, lighting and thermal comfort, mobility, driving force, etc.