Double-check baseline emissions

[MarkMDekker]

The baseline emissions for NLD have a strange wiggle. Also let's double check everything happening there. Potentially scale with Climate Solutions Explorer.

[MarkMDekker]

Okay, I'm diving into this. It seems that we used a very simple offset harmonization of the baseline downscaled emissions from Rik to the historical CO2 emissions. The gap is pretty big between those, so I now implemented a fraction-based harmonization. That means that I divide the full downscaled graph by the same factor, rather than subtracting a constant emission difference between the downscaled CO2 graph (red, only based on CO2|Energy) and the historical real CO2 emissions (blue).

The fraction (or factor)-based one is then red, and then I assume non-CO2 to have the same development as CO2 in the baseline (ups and downs), relative to the 2021 level. Then you add that non-CO2 part and come to the grey line. The previous version had the green line. So our baseline emissions for the Netherlands are lifted a little bit.

Now, if you compare to India, the new baseline emissions become quite a bit higher, so it is quite sensitive to this:

You also see that the World's baseline emissions are a bit higher (grey now, instead of green):

Then, going to what is the fraction of the world's baseline emissions, which is ultimately very important in the GDR computations, we see that indeed, the Dutch baseline emissions as fraction of the globe has decreased in this new way of utilizing the downscaled emissions:

[MarkMDekker]

Still, I believe this is the better way of using the downscaled emissions that we have. I will commit this now and then try to see what we can learn from the Climate Solutions Explorer (which does not have downscaled baseline emissions, but only curpol emissions).

[rikvanheerden]

The wiggle is also present in TIMER results for Western Europe. The demand for electricity is increasing rapidly, and initially, it seems that the deployment of renewable energy sources cannot match this pace. As a result, additional fossil fuel technologies are being deployed in the first few decades. Unfortunately the colors seem wrong in the second graph: I believe pink should be coal instead of nuclear.

[MarkMDekker]

Did you show this to Harmen-Sytze? Do you think we should talk about this? Probably we will have to accept this as it is. Do we also see this wiggle in emissions, rather than energy?

[rikvanheerden]

Did you show this to Harmen-Sytze? Do you think we should talk about this? Probably we will have to accept this as it is. Do we also see this wiggle in emissions, rather than energy?

Not yet. I also noticed that the figures changed quite a bit for the TIMER 3.4 calibration outputs, so this is indeed something to discuss tomorrow. And yes, the wiggle clearly shows up in emissions.

[MarkMDekker]

Yes, let's discuss this. One alternative would be to use (IMAGE) baselines as they are in the AR6 database. They are vetted, etc. Curious to the TIMER 3.4 outputs.

[rikvanheerden]

An issue directly related to downscaling (does not explain the full difference in CO2 emissions): Primary Energy|Coal decreased rapidly in Western Europe in the past couple of years, which is not captured in TIMER. This leads to higher baseline emissions from coal if we apply harmonization.

Downscaled results WITHOUT harmonization and using base year 2021:

[rikvanheerden]

Another potential issue is that, from what I understand, the energy and emissions accounting for IAMs includes bunkers, which EDGAR/PRIMAP/KEV probably do not account for.

[MarkMDekker]

Rik and I decided that we will dig into other versions of baselines, to see whether the currently used baselines are really far off in other respects as well:

• The newest IMAGE SSPs (maybe only SSP1-2, however)
• IMAGE SSP baselines in the AR6 database
• Baselines from other models (only on R10 or global aggregation)

[MarkMDekker]

We will also meet up with HS asap. @harmensytze

[rikvanheerden]

Primary Energy|Coal for different baselines (WEU):

[MarkMDekker]

From the new (H2A baseline) runs that HS now did, these are CO2 emissions for WEU:

And this is primary energy use for WEU: