Share this page!

Glen Peters Profile picture
Twitter logo
12 Oct, 6 tweets, 11 min read
@timinmitcham @kmac @bataille_chris @SvenTeske @JoeriRogelj @IEA I have not put all the IEA WEO2019 into my system, but I show what I have. CO2 was tweeted earlier. I show a figure for 1.5C (no and low overshoot from IPCC) & Lower 2C (around 66% <2C). IEA is sort of in between in terms of carbon budget (I think).

This is coal.

1/ ImageImage
@timinmitcham @kmac @bataille_chris @SvenTeske @JoeriRogelj @IEA Oil. Which interestingly, IEA generally is lower on oil (but still argues because of decline in existing fields, there is more space for oil investments).

2/ ImageImage
@timinmitcham @kmac @bataille_chris @SvenTeske @JoeriRogelj @IEA Gas. Where IEA is higher than most others. Though, there is quite some spread... ImageImage
@timinmitcham @kmac @bataille_chris @SvenTeske @JoeriRogelj @IEA Solar. This is not such a good example, as most of the high scenarios are from one model (REMIND), so hard to see the details (unless I zoom in) ImageImage
@timinmitcham @kmac @bataille_chris @SvenTeske @JoeriRogelj @IEA And CCS. Generally, the IEA is naturally on the low side when it comes to CCS, which surprises most people...

Overall, I don't see much evidence that the IEA is pro-fossil in comparison to many other scenarios, & some other scenarios are far more pro fossil because of CCS. ImageImage
@timinmitcham @kmac @bataille_chris @SvenTeske @JoeriRogelj @IEA WEO2020 comes tomorrow, so I should put in some more effort and plot additional variables... It is about time I did another bigger comparison with IPCC SR15 & IEA WEO...

/end (forgot to number the tweets)

• • •

Missing some Tweet in this thread? You can try to force a refresh
　

Keep Current with Glen Peters

Glen Peters Profile picture

Stay in touch and get notified when new unrolls are available from this author!

Read all threads

This Thread may be Removed Anytime!

PDF

Twitter may remove this content at anytime! Save it as PDF for later use!

Try unrolling a thread yourself!

how to unroll video
  1. Follow @ThreadReaderApp to mention us!

  2. From a Twitter thread mention us with a keyword "unroll"
@threadreaderapp unroll

Practice here first or read more on our help page!

More from @Peters_Glen

Glen Peters Profile picture
15 Oct
THREAD: The @IEA now has an aggressive 1.5°C scenario, reaching net-zero by 2050.

It builds on the Sustainable Development Scenario, strengthening reductions in power & end-use, but with new behavioural measures.

The light blue scenarios are IPCC SR15.

iea.org/reports/world-…
2. Contrary to the view of many, the Sustainable Development Scenario (SDS) was already quite aggressive (~1.65°C).

The Net-Zero 2050 Scenario (NZE2050) is more aggressive than the SDS on power & end-use, but also includes some additional behavioural measures.
3. The thing with the behavioural measures is that you have to do a lot of them, & they are quite specific & targeted. This is on top of aggressive technological change.

The point is that 1.5°C requires pulling on pretty much every level, to the max. Now, not tomorrow.
Read 16 tweets
Glen Peters Profile picture
8 Oct
THREAD: N₂O

We have a new paper in @nature on nitrous oxide (N₂O), five years in the making!

Like many GHGs, N₂O concentrations have been stable for thousands of years, but that balance between sources & sinks has been dramatically changed by humans.

rdcu.be/b8cgZ
2. N₂O is a potent GHG, 300 times worse than CO₂ over 100 years (GWP). It destroys the ozone layer & contributes to water pollution.

N₂O is ~7% of current radiative forcing, but because of its long lifetime & difficulty to mitigate, this will increase even in 1.5°C scenarios.
3. N₂O comes almost equally from natural (60%) & anthropogenic sources (40%).

Natural sources are dominated by microbial processes that break down nitrogen-containing compounds in the soil & oceans. These sources have previously balanced with the atmospheric chemical sinks.
Read 12 tweets
Glen Peters Profile picture
7 Oct
There is often an assumption that the more aggressive climate targets means more BECCS.

This is only weakly true, many 2°C scenarios use as much BECCS as 1.5°C scenarios, & even >2.5°C scenarios use BECCS at scale!

IAMs just love BECCS 😍🥰😘

1/
These are scenarios that go over 2°C. Yes, some scenarios use over 20GtCO₂/yr in 2100 (we currently emit 40GtCO₂/yr). These are not aggressive mitigation scenarios, these are >2°C, & where we could end up with only weak climate policies like we have today.

2/
It is not that 1.5°C or 2°C (or even 3°C) needs large-scale BECCS, this is just the cost-effective pathway that most IAMs find. This could be for a variety of structural reasons.

Since BECCS is so prolific in scenarios, we obsess over it. It may just be a model artifact!

3/
Read 6 tweets
Glen Peters Profile picture
6 Oct
Even though N₂O’s Ozone Depletion Potential is only 0.017, roughly one-sixtieth of CFC-11s, the large anthropogenic N₂O emissions make N₂O the single most important source of ozone depletion (that was in 2009!)

1/
science.sciencemag.org/content/326/59…
For the emission metric nerds out there, there is a close historical link between the Global Warming Potential (GWP) and the Ozone Depletion Potential (ODP).

The paper uses GWP & ODP, to contrast climate & ozone impacts.

2/
If you want to understand the GWP, read up on the ODP...

In this paper on the integrated Global Temperature change Potential (iGTP) I dug into some of the history, & it made me understand the GWP much better...

3/
iopscience.iop.org/article/10.108…
Read 4 tweets
Glen Peters Profile picture
6 Oct
The results of yesterdays poll on EU climate ambition.

There was some ambiguity with the question, essentially to what degree the EU should adjust to the ambition of others.

There was a reason for the way I posed the question, around net-zero, linking to the ">2°C" option

1/
Scenarios with 50% chance of staying below 2°C rarely reach net-zero GHG by the end of the century (from IPCC SR15). The EU is aiming for net-zero GHG in 2050. The EU, in this case, would be more than 50 years ahead of the global average.

2/
This is the temperature response from those scenarios, still below 2°C (median in 2100 is 1.8°C).

So, to pick the option that the EU is consistent with over 2°C (>2°C in the poll) is rather extreme, & I would say inconsistent with the science (sorry).

3/
Read 7 tweets
Glen Peters Profile picture
5 Oct
How is a 1.5°C scenario defined?

It should be simple to define? No? These are the definitions used in IPCC SR15, which has three types of 1.5°C scenarios depending on "overshoot".

This has implications...

1/ Image
The Paris agreement has "well below 2°C ... pursing ... 1.5°C". A broad interpretation would be somewhere between 1.5°C-2°C (closer to 1.5°C).

This is where the SR15 scenarios go. The 1.5°C scenarios are generally below 1.5°C except for a period of over 1.5°C.

And so?

2/ Image
This 'overshoot' has big implications for Carbon Dioxide Removal (CDR). Here is CDR just from BECCS... Add on top of this CDR from afforestation!

Choosing aggressive definitions of 1.5°C generally requires assuming more CDR. Which is fine, as long as this trade-off is clear.

3/ Image
Read 4 tweets

Did Thread Reader help you today?

Support us! We are indie developers!

This site is made by just two indie developers on a laptop doing marketing, support and development! Read more about the story.

Become a Premium Member ($3/month or $30/year) and get exclusive features!

Become Premium

Too expensive? Make a small donation by buying us coffee ($5) or help with server cost ($10)

Donate via Paypal Become our Patreon

Thank you for your support!

Follow Us on Twitter!

Like this author's thread?

Get email notifications when new thread is out from this Author!

Check out other threads from this Author!

Read all threads by @Peters_Glen