There is a strong argument (backed by studies) that current / stated policies are consistent with ~3°C warming by 2100.
Many are sceptical of this given current trends. But what does coal, oil, & gas do in 2-3.5°C pathways through to 2100?
THREAD
thebreakthrough.org/issues/energy/…
Many are sceptical of this given current trends. But what does coal, oil, & gas do in 2-3.5°C pathways through to 2100?
THREAD
thebreakthrough.org/issues/energy/…
(Figures show SSPs with 3.4, 4.5, 6.0W/m² in 2100, bold is median in each group)
Coal use pretty much levels out in weak scenarios or declines in moderate scenarios. Given current trends in coal, this sounds quite plausible without additional policies.
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Coal use pretty much levels out in weak scenarios or declines in moderate scenarios. Given current trends in coal, this sounds quite plausible without additional policies.
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Oil use could peak in 2060 for >3°C, but 2-3°C scenarios could have oil peaking 2030 to 2040.
Many oil majors have oil peaking in the 2030s to 2040s, so one could consider this rather conservative.
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Many oil majors have oil peaking in the 2030s to 2040s, so one could consider this rather conservative.
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Gas use continues to grow in many moderate scenarios. In the short term current trends continue to around 2040, & a peak likely occurs after 2040 with only a gradual decline. afterwards.
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The real spanner in the works is CCS. CCS is really high even in moderate scenarios. Up to 10GtCO₂/yr could be used by 2050, allowing higher fossil fuel use than otherwise.
In a weak to moderate policy scenario, I find it highly unlikely CCS would be used at these scales.
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In a weak to moderate policy scenario, I find it highly unlikely CCS would be used at these scales.
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CCS could be understandably important in deep mitigation scenarios cicero.oslo.no/no/posts/nyhet…, but IAMs seem to have an overly strong attraction to CCS in weak mitigation scenarios.
There needs to be a better understanding on why IAMs use so much CCS in these weak scenarios.
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There needs to be a better understanding on why IAMs use so much CCS in these weak scenarios.
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This coal, oil, & gas use, combined with the CCS (& BECCS), leads to a peak in global CO₂ emissions in 2050 for weak policy scenarios (>3°C) & an immediate peak for 2-2.5°C scenarios.
Certainly, ~3°C is not a radical mitigation scenario (via coal, oil, & gas pathways)
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Certainly, ~3°C is not a radical mitigation scenario (via coal, oil, & gas pathways)
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Land-use change emissions are also important, with even weak mitigation scenarios leading to net afforestation by around 2050.
This requires a big change in trend, perhaps more challenging then reducing fossil fuel use?
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This requires a big change in trend, perhaps more challenging then reducing fossil fuel use?
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Overall, many may see 3°C pathways as something more akin to current trends continue. Many baselines (without climate policy) follow similar trends. High end baselines (like RCP8.5) require acceleration in fossil fuel use.
We should mitigate as fast & deep as possible!
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We should mitigate as fast & deep as possible!
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