Ultimately, all fossil fuels need to be phased out concurrently to avoid the worst of climate disasters Connecting the dots between LNG, climate change and marine biodiversity
By Dr. Alejandro Frid
Q/ What is liquefied natural gas (LNG)?
Natural gas is a fossil fuel composed primarily of methane (85% or more)[a]. Industry ‘liquefies’ natural gas into LNG to improve transport and storage efficiencies. The liquefaction process is very energy-intensive and often fueled by natural gas. In BC there is an intention to increase the use of electricity from dams, such as Site C, for liquefaction[b].
Q/ What is the direct climate impact of natural gas relative to that of other fossil fuels?
The answer depends on time scale1,2. Over one hundred years or more, natural gas has a lower direct impact on the climate than other fossil fuels. Over 20 years or less, natural gas has a stronger direct impact on climate change2. The reasons are:
- 1) CO2 emissions produced during extraction, transport and consumption are lower for natural gas than for other fossil fuels. CO2 persists in the atmosphere for centuries, which is why natural gas has a lower direct impact on the climate over one hundred years or more1,2.
- 2) Of all fossil fuels, however, natural gas has the highest rate of methane emissions. Although the direct climate impact of methane lasts only a few decades, the global warming produced by methane over 20 years is 86 to 105 times greater than that produced by an equivalent mass of carbon dioxide (according to the three most recent estimates)2.
Q/ If methane emissions have a strong direct impact on climate for only a few decades, does that mean that the overall climate impact of natural gas is low?
No, the overall climate impact of natural gas can be quite large1,2. Sustained warming caused by methane over 20 years at a rate that is 86 to 105 times stronger than CO2 can contribute to “positive feedback loops”—indirect mechanisms in which relatively small temperature rises initiate other processes that accelerate further heat1,2. For instance, warming in the Arctic and Subarctic already has reduced the area covered by summer sea ice and begun to melt permafrost. Consequently, solar radiation that would have been reflected back to space by white sea ice is now absorbed by dark unfrozen ocean, and the melting permafrost releases greenhouse gases that had been stored frozen underground. Both of these mechanisms exacerbate global warming3,4. Due to these sorts of positive feedback loops, the short-term yet powerful warming associated with methane emissions make the overall climate impact of natural gas very significant. As climate scientist Robert W. Howarth emphasises, reducing methane emissions over the next 15-35 years is critical to avert severe runaway climate change disasters2.
Q/ When does natural gas emit methane?
Methane emissions associated with natural gas are a by-product of field extraction and processing (upstream emissions), and of storage, long-distance transport, and distribution (downstream emissions)2,5. Combustion of natural gas also emits methane (along with CO2, and other greenhouse gases), yet the extent of these emissions depends on efficiency of the technology being used to generate heat or electricity2[c].
Q/ Do other fossil fuels emit methane during production, transport and combustion?
Yes. Natural gas, however, has a higher methane content and therefore is associated with a higher rate of methane emissions than other fossil fuels[d].
Q/ The BC government is promoting massive extraction and export of LNG as a “green” solution to climate change. What is their logic?
BC government propaganda has focused on the fact that CO2 emissions from natural gas are lower than for other fossil fuels, and that methane emissions last relatively short periods of time in the atmosphere. Their argument for LNG as a “climate solution”, however, is flawed because it fails to account for the tremendous warming potential of methane over 20-year periods, and how such warming might contribute to runaway climate change. Also, as climate scientist and MLA Andrew Weaver points out, the BC government has not accounted for the large amounts of natural gas required to fuel large-scale liquefaction and that increase the climate impacts of LNG[e].
How do methane emissions from LNG affect marine biodiversity indirectly?
Not decreasing emissions from fossil fuels, LNG included, may indirectly impacts marine biodiversity. Among other impacts, warming increases susceptibility to disease for salmon6 and other species and—by altering the timing of migration and the quality of spawning habitat7—can increase pre-spawning mortality. The consequences of warming and ocean acidification extend beyond salmon to many other species, including shellfish, herring, eulachon, seaweed and groundfish8-12.
What about other fossil fuels?
LNG is not the lone climate concern. Ultimately, all fossil fuels need to be phased out concurrently to avoid the worst of climate disasters1,13 and associated impacts on marine biodiversity.
Dr. Alejandro Frid is a conservation ecologist and the science coordinator for the Central Coast Indigenous Resource Alliance. To learn more about his work go to http://alejandrofridecology.weebly.com/.
Illustration at top of page: School of Black Rockfish in Haida Gwaii. If greenhouse gas emissions continue unabated, Black Rockfish will be among the many types of predatory fishes expected to move to higher latitudes and shift to deeper depths in search of cooler temperatures, and to shrink in size due to the combined physiological effects of warmer water and lower oxygen levels. These changes are predicted to indirectly alter the predator-prey relationships that shape kelp forests (shown in the picture) and other marine communities Photo credit: Rowan Trebilco
[a] US Environmental Protection Agency: http://epa.gov/climatechange/ghgemissions/gases/ch4.html
[b] Andrew Weaver, climate scientist and MLA: http://www.andrewweavermla.ca/lng-facts-comments/
[c] US Environmental Protection Agency: http://epa.gov/climatechange/ghgemissions/gases/ch4.html
[d] US Environmental Protection Agency: http://epa.gov/climatechange/ghgemissions/gases/ch4.html
[e] Andrew Weaver, climate scientist and MLA: http://www.andrewweavermla.ca/lng-facts-comments/http
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