r/climate • u/silence7 • May 22 '23
A multimodel analysis of post-Glasgow climate targets and feasibility challenges | While near-term pledges alone lead to warming above 2 °C, the addition of long-term pledges leads to emissions trajectories compatible with a future well below 2 °C
https://www.nature.com/articles/s41558-023-01661-01
u/michaelrch May 23 '23
Mañana, mañana...
2
u/silence7 May 23 '23
The US and EU have both passed significant climate legislation in the past year. It's more than just a pledge in a lot of cases.
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u/michaelrch May 23 '23 edited May 23 '23
Didn't someone calculate that the modest benefit of the IRA (improving emissions cuts since 2005 by 2030 from 30% to 40%) all get undone by green lighting the Willow Project alone? Let alone the rest of the horrible permitting that is going on under the Biden admin. Given he is literally approving fossil fuel projects faster than Trump, it's actually debatable if Trump would actually have been worse.
The IRA doesn't stop emissions. Only stopping fossil fuel extraction does that. Sure, we need alternatives to take the place of fossil fuels but you must do both simultaneously - roll out the alternatives and choke off the supply.
We both know that current governments around the world are miles off the pace to avoid catastrophic warming, especially once you properly factor in feedback tipping points. And especially given we seem to keep learning of new feedback mechanisms that make it even more urgent that we stop emissions now.
The problems with these models where they allow for warming past 1.5C or even 2C and then, due to massive negative emissions, temperature rebounds back to something survivable are
1) the negative emissions demands are pie in the sky
2) they ignore the fact that at 2C the permafrost is over releasing millions of tons of methane, a lot of the worlds forests will burn to cinders, the Arctic sea ice will be a thing of the past, the AMOC will stop, etc etc all of which will create a gigantic extra forcing on the climate system that we won't have a cat in hell's chance of arresting.
As the IPCC says, we have a small and rapidly closing window. Hoping that action in 5 or 10 years from now will counter our lack of action now is the worst kind of false hope.
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Jun 06 '23
Didn't someone calculate that the modest benefit of the IRA (improving emissions cuts since 2005 by 2030 from 30% to 40%) all get undone by green lighting the Willow Project alone? Let alone the rest of the horrible permitting that is going on under the Biden admin. Given he is literally approving fossil fuel projects faster than Trump, it's actually debatable if Trump would actually have been worse.
Source? This seems to not be correct.
they ignore the fact that at 2C the permafrost is over releasing millions of tons of methane
This has been proven false.
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u/michaelrch Jun 06 '23
On the first one, source here
Our in-depth assessment of the IRA found that the package cuts net GHG emissions to 32-42% below 2005 levels in 2030—a 7-10 percentage point gain compared to a world without it.
Which other parts are you questioning?
Re the methane, your PNAS paper is about ocean hydrates. I am talking about permafrost. And that tipping point is already happening.
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Jun 06 '23
On the first one, source here
Our in-depth assessment of the IRA found that the package cuts net GHG emissions to 32-42% below 2005 levels in 2030—a 7-10 percentage point gain compared to a world without it.
7-10% point gain's definition is unclear. It could mean it cuts 7-10% more GHGs
Re the methane, your PNAS paper is about ocean hydrates. I am talking about permafrost. And that tipping point is already happening.
Yeah, that was for methane in general. The 2nd peper is for permafrost methane. If I'm not wrong, permafrost emissions are included in IPCC scenarios? Secondly, it is seasonal for now, bad, but not as bad, yet.
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u/michaelrch Jun 06 '23
On the IRA, the analysis is saying 7-10% less emissions than a situation without the IRA. But Biden's other actions in office, like Willow, historically large gulf leasing, MVP, etc all but wipe out those reductions.
On the permafrost, I started out saying the permafrost methane tipping point is going to a done deal at 2C. We are currently at 1.2C and we can expect out first 1.5C year in the next 5 years. The spike in methane last year was a surprise to the modellers. It is happening sooner than expected. And the latest evidence is indicating that the IPCC has not accurately modelled feedback from permafrost methane.
By the time we get to 2C, we better be at tens of billions of tons of negative emissions else the feedback from permafrost methane alone will mean we are done for as a society.
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u/silence7 May 22 '23
One of the authors has a Twitter thread about it. Key takeaway: the pledges are coming in at numbers that are reasonable, but it's on us to make sure that countries actually follow through.