Natural gas has long been billed as a good steppingstone 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 stand-in 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 transport mean natural gas isn’t as climate-friendly as once thought.
By 2030, the world will need to cut is greenhouse gas emissions by more than 40 percent if it’s to meet the most ambitious goals of the Paris Agreement, according to the Intergovernmental Panel on Climate Change, a United Nations body. In an interview, Mark Radka, Head of the United Nations Environment Programme’s (UNEP) Energy and Climate Branch, talked about the role natural gas should play in reducing emissions and the transition to a renewable energy future.
Is natural gas a cleaner alternative to coal or oil in terms of emissions?
Natural gas is a cleaner fuel in the sense that burning it produces fewer conventional air pollutants, like sulphur dioxide and particulates, than does burning coal or oil. How much more depends on the characteristics of the fuel, the combustion technology, how well equipment is maintained and operated, and other factors. In general, burning natural gas also produces less carbon dioxide per unit of energy – about half compared to the best coal technology – and by this measure it’s better from a climate perspective.
Researchers have discovered massive amounts of methane, a potent greenhouse gas, leaking from natural gas facilities around the world. Does that call into question the notion that natural gas is cleaner than other fossil fuels?
Recent scientific measurement campaigns, some of them supported by UNEP, have shown that methane emissions from oil and gas operations are much higher than was estimated earlier. Methane is a powerful greenhouse gas, about 84 times more potent than carbon dioxide measured over a 20-year period, so any emissions undermine its credentials as a better fossil fuel. So, “cleaner” is probably not the best word to describe natural gas. But provided that methane emissions are well managed, it’s not as problematic in terms of planetary warming as coal or oil.
Is it unrealistic to expect fossil fuel companies to police methane leaks?
I believe it’s unrealistic to expect that all fossil fuel companies would police themselves so regulations capping emissions levels and good enforcement certainly are crucial. But many companies are willing to act even without regulatory pressure. We’re working with many companies that have committed to setting 2025 methane reduction targets, measuring their methane emissions, taking steps to reduce these, and reporting on the results. Detection technologies are improving, and UNEP is, in parallel working 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 started, construction has reportedly begun on about 20 liquified natural gas receiving terminals across the globe, including in Germany and China, resulting in a growing percentage of methane transported by sea. Are ships more prone to methane leaks than pipelines?
The straight answer is that this is currently unknown but it is knowable in principle. There is a lack of empirically verified measurement data throughout the entire natural gas industry, which is exactly why UNEP initiated the International Methane Emissions Observatory (IMEO). Most methane data is based on emission factor estimates, rather than actual measurements. UNEP’s objective with IMEO is to provide factual answers to these sorts of questions.
UNEP’s Emissions Gap Report says we must cut greenhouse gas emissions by up to 45 percent by 2030 to skirt a full-blown climate crisis. Is natural gas a good bridge fuel for countries seeking to transition away from coal and oil?
It all depends on the speed of the transition, which science tells us must be rapid to avoid the worst consequences of climate change. A long or slow transition away from other fossil fuels and which requires lots of investment in gas infrastructure would make for a bad bridge. In many countries natural gas has already replaced coal as the fuel of choice for electricity production, with climate and air quality benefits. The rapid decrease in the cost of solar, wind and other renewable energy technologies makes these an even better alternative than gas in more and more locations.
Where gas has a special role in the energy transition is as a back up to a renewable-based power system because gas boilers can be turned on almost instantly while starting up a coal-fired power plant takes much longer. There’s a lot of research and deployment of energy storage technologies so this role for gas will diminish.
With costs of renewable energy at record lows, why do some countries still choose to invest in natural gas? What are the biggest issues when it comes to transitioning to wind and solar?
It’s important to remember that with current technologies not all energy sources are interchangeable. Aircraft and shipping, for example, still rely predominantly on fossil fuels as do some so-called hard-to-abate industrial sectors, like iron smelting. Much research and development is underway and much more is needed in areas like storage but we’re not yet to the stage where all fossil fuels can be replaced by renewable energy.
The world is getting more electrified, and wind and solar energy will be increasingly important, particularly in places where the renewable energy resources – sunshine and wind – are plentiful. It’s important to keep in mind that we’re in the early stages of an energy transition that is unlike any the world has ever attempted in terms of speed and complexity. It is a transition, though, and any transition takes time and persistence. That said, we must move quickly.
Are there better alternatives to natural gas for countries that cannot invest in wind or solar?
Every country and every person need to think more critically about energy efficiency. We never value energy for its own sake; we value instead the many services that energy makes possible. I’m speaking here about communication, lighting and thermal comfort, mobility, motive power and so on.
If we can get those services by consuming less energy, we’re better off and so is the planet. Most countries do have either solar or wind potential or both. Other alternatives already in play are hydropower, large or small, geothermal, as in Kenya and Iceland, sustainable biomass and maybe in the future ocean current or tidal energy plants, both of which exist as pilots but come with other environmental concerns.