Thread by @Peters_Glen

Many accept that the coal use in RCP8.5 is a tad high, but then some fall back on arguments about gas (eg hydrates).

Well, to get RCP8.5 with *only* gas (no coal or oil) would require an 18.5 fold increase in today's gas use by 2100…

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Calculation: 2250EJ with emission factor 54,000kgCO₂/TJ gives 126GtCO₂ in 2100 (as per RCP8.5 CO₂ emissions).

Alternatively: RCP8.5 has 1800EJ in 2100 (using coal, oil, gas), using gas only (54,000kgCO₂/TJ) gives 102GtCO₂ in 2100.

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The RCPs are just representative pathways, so in theory there are many ways to get to any given forcing level (RCP).

But, it is likely that it is only possible to get to RCP8.5 with lots of coal (gas is too “clean”, even for RCP8.5).

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There may be 1 million EJ of gas hydrates, but of course, how much can be (& would be) extracted is more important than the resource (“the stone age didn’t end for the lack of stones”)

foreignpolicy.com/2020/01/09/fra…

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To exploit hydrates, the costs would have to at least compete with solar & wind, also with nuclear, what about fusion (?), & also conventional coal & gas if the world walks back from climate change.

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If hydrates could be extracted and used at a competitive price with solar & wind (say by 2050), then adding CCS would still mean they are cheap (relative to today).

(But, given likely costs of solar & wind in 2050, the price to extract gas from hydrates would have to be low!

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Yes, “widespread use of methane hydrates could upend global energy markets”. Focus on the word “could”.

(note, the article is more about geopolitics, but worth a read)

foreignpolicy.com/2020/01/09/fra…

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