Liquefied natural gas carbon footprint is worse than coal | Cornell Chronicle
Liquefied natural gas carbon footprint is worse than coal Cornell Chronicle
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The Greenhouse Gas Footprint of Liquefied Natural Gas (LNG) Exported from the United States
Liquefied natural gas leaves a greenhouse gas footprint that is 33% worse than coal, when processing and shipping are taken into account, according to a new Cornell study.
“Natural gas and shale gas are all bad for the climate. Liquefied natural gas (LNG) is worse,” said Robert Howarth, author of the study and the David R. Atkinson Professor of Ecology and Environmental Biology in the College of Agriculture and Life Sciences. “LNG is made from shale gas, and to make it you must supercool it to liquid form and then transport it to market in large tankers. That takes energy.”
The research, “The Greenhouse Gas Footprint of Liquefied Natural Gas (LNG) Exported from the United States,” published Oct. 3 in Energy Science & Engineering.
Key Findings
- The emissions of methane and carbon dioxide released during LNG’s extraction, processing, transportation, and storage account for approximately half of its total greenhouse gas footprint.
- Over 20 years, the carbon footprint for LNG is one-third larger than coal, when analyzed using the measurement of global warming potential.
- Even on a 100-year time scale, the liquefied natural gas carbon footprint equals or still exceeds coal.
Implications for LNG Production in the U.S.
The findings have implications for LNG production in the U.S., which is the world’s largest exporter, after it lifted an export ban in 2016, according to the paper. Almost all of the increase in natural gas production since 2005 has been from shale gas. Howarth said the exported LNG is produced from shale in Texas and Louisiana.
Environmental Impact of Transportation
The liquefaction process – where the extracted natural gas is cooled to minus 260 degrees Fahrenheit – makes LNG easier to transport on tanker ships.
But that mode of transportation comes at an environmental cost. The ships with two- or four-stroke engines that transport LNG have lower carbon dioxide emissions than steam-powered ships. But as those stroke-engine vessels burn LNG during storage and transportation, methane slips through as emitted exhaust gas, putting more into the atmosphere.
Methane is more than 80 times more harmful to the atmosphere than carbon dioxide, so even small emissions can have a large climate impact, Howarth said.
That’s why, he said, the modern LNG tankers with two- and four-stroke engines have more greenhouse gas emissions than those tankers powered by steam. Regardless of better fuel efficiency and lower carbon dioxide emissions, methane still escapes in the tanker’s exhaust.
And significant methane emissions occur in the natural gas liquefaction process, a figure close to 8.8% of the total when using the global warming potential. Methane emissions from tankers vary from 3.9% to 8.1%, depending on the ship.
Conclusion
“Almost all the methane emissions occur upstream when you’re extracting the shale gas and liquefying it,” Howarth said. “This is all magnified just to get the liquefied natural gas to market.
“So liquefied natural gas will always have a bigger climate footprint than the natural gas, no matter what the assumptions of being a bridge fuel are,” Howarth said. “It still ends up substantially worse than coal.”
The research was supported by a grant from the Park Foundation. Howarth is a fellow at the Cornell Atkinson Center for Sustainability.
SDGs, Targets, and Indicators
1. Which SDGs are addressed or connected to the issues highlighted in the article?
- SDG 7: Affordable and Clean Energy
- SDG 13: Climate Action
- SDG 14: Life Below Water
2. What specific targets under those SDGs can be identified based on the article’s content?
- SDG 7.2: Increase substantially the share of renewable energy in the global energy mix
- SDG 13.2: Integrate climate change measures into national policies, strategies, and planning
- SDG 14.2: Sustainably manage and protect marine and coastal ecosystems
3. Are there any indicators mentioned or implied in the article that can be used to measure progress towards the identified targets?
- Indicator for SDG 7.2: Proportion of total energy consumption from renewable sources
- Indicator for SDG 13.2: Number of countries with integrated policies, strategies, and plans for climate change mitigation, adaptation, impact reduction, and early warning
- Indicator for SDG 14.2: Proportion of coastal and marine areas protected
4. Table: SDGs, Targets, and Indicators
| SDGs | Targets | Indicators |
|---|---|---|
| SDG 7: Affordable and Clean Energy | Increase substantially the share of renewable energy in the global energy mix | Proportion of total energy consumption from renewable sources |
| SDG 13: Climate Action | Integrate climate change measures into national policies, strategies, and planning | Number of countries with integrated policies, strategies, and plans for climate change mitigation, adaptation, impact reduction, and early warning |
| SDG 14: Life Below Water | Sustainably manage and protect marine and coastal ecosystems | Proportion of coastal and marine areas protected |
Based on the article, the issues discussed are connected to SDG 7 (Affordable and Clean Energy), SDG 13 (Climate Action), and SDG 14 (Life Below Water). The specific targets identified are SDG 7.2, SDG 13.2, and SDG 14.2. The article mentions or implies indicators that can be used to measure progress towards these targets, such as the proportion of total energy consumption from renewable sources (SDG 7.2), the number of countries with integrated policies for climate change (SDG 13.2), and the proportion of coastal and marine areas protected (SDG 14.2).
Source: news.cornell.edu
