Using natural gas as a climate solution will become a climate problem

This column is an opinion by academic researchers Sara Hastings-Simon, Arvind Ravikumar and Shuting Yang. For more information about CBC's Opinion section, please see the FAQ.

A commonly heard claim from oil and gas boosters is that Canada should export more liquefied natural gas (LNG) as a climate solution by replacing coal as a source of power generation in other countries. 

The Government of Alberta's own Canadian Energy Centre, the so-called war room, points to LNG as a tool for emissions reductions, going as far as to state that "growing Canadian LNG exports is necessary if the world is to meet its Paris commitments of keeping global warming well below 2 degrees Celsius."

These claims are at best misleading.

Under the right conditions, additional LNG can reduce power sector emissions but only if there is sufficient existing coal-based generation to substitute. Otherwise, the new supply of natural gas ends up displacing lower-emitting sources such as renewables or nuclear.

This makes LNG only a short-term opportunity. By the 2030s, additional LNG becomes a problem for a world that is cutting emissions to meet its climate goals. It would either create stranded assets out of costly new LNG export terminals or lock in emission growth that takes us in the wrong direction on climate change.

In other words, investing in new LNG infrastructure means either committing to carbon emissions or putting in a lot of money only to abandon infrastructure before its designed lifetime.

In our recently published research, we test these claims by asking: Under what conditions does using LNG to switch from coal to gas in the electricity sector help reduce global greenhouse gas emissions?

The question is critical for Canada, where 24 LNG projects have been issued long-term export licences, a subset of which may proceed. Export terminals require significant infrastructure development, including controversial gas pipelines and federal and provincial subsidies.

For LNG to reduce emissions, two conditions must be satisfied: 1) methane leakage along the natural gas supply chain is low, a challenge as recent measurements indicate methane emissions in Canada are higher than previously estimated, and 2) LNG displaces coal-based electricity generation rather than other lower-emitting sources of electricity such as renewable energy.

LNG can help in the near-term. There is significant coal-based generation remaining in the world today that could be substituted by natural gas. However, in a 1.5-degree or 2-degree compatible world — as is called for under the Paris agreement — all coal-based generation would be replaced by natural gas or renewables by 2030 or 2038, making the coal-to-gas transition argument moot.

To remain on a Paris-compliant pathway, the world would need to replace these natural gas plants with lower-emitting generation. This effectively creates an expiry date for the use of LNG as a climate solution.

Even this best-case scenario ignores serious infrastructure challenges. For example, places that would benefit the most from a coal-to-gas transition — like India with its large fleet of young coal power plants — are also the places most likely to not have the physical infrastructure such as pipelines to support a shift to gas.

Whether a coal-to-gas transition is desirable or even feasible in such scenarios depends on the cost of building out these new pipelines and the risk of locking in future emissions by doing so. In theory, LNG could substitute for other uses of coal in heating or industrial applications, but with the same types of constraints around substitution.