Thread by @AukeHoekstra

Warning for the consequences of climate change is important!
(I devote my life to this stuff...)

But it's not helpful to keep repeating an alarmist scenario that relevant scientists think is highly unlikely.

Let me explain. (Again.)
theguardian.com/environment/20…

To be clear: professionally I would love for the most alarming facts to be true!
It makes what I do more important!

But I have 4 problems:

1) It's not true
2) It damages science
3) It gives children depressions
4) Doing nothing looks like achievement (compared to the scenario)

Now the explanation.

The venerable @IPCC_CH has one set of scenarios in which we get rich quick and only burn fossil fuels: SSP5.

In the worst scenario we use 6x more coal PER CAPITA in 2100.

This scenario was called RCP 8.5 and is now called SSP5-8.5.

https://twitter.com/AukeHoekstra/status/1285917335480684544

1st person I know who called BS on this is @jritch who's PhD thesis showed that this coal explosion was implausible.

That message was so unwelcome that he left climate science and now produces xenetwork.org/ets/ with @chrisnelder.

Here he explains again what went wrong together with @RogerPielkeJr.

Roger has a following of climate deniers and doesn't mind confrontation but is absolutely not a climate denier himself. Like me he is simply a stickler for getting facts right. issues.org/climate-change…

Two more influential people in this space that called BS are IPCC authors @hausfath and @Peters_Glen.

Here they explain it in @nature in 2020.
nature.com/articles/d4158…

Here on twitter the biggest ruckus was created by @MLiebreich promoting the hashtag #RCP85isBollox. And he dragged me into it until I called up @jritch and many others, and became the most commenting person on this topic for a few harrowing months.

https://twitter.com/PietroMonticone/status/1208848359890542592

Here's Michael talking to influential friends about #RCP85isBollox (and other things).

E.g.
@ramez

https://twitter.com/MLCleaningUp/status/1314626545202462723

@jrockstrom

https://twitter.com/MLiebreich/status/1413738766670389249?s=20

Prof Jim Skea

https://twitter.com/MLiebreich/status/1375864477955063814?s=20

I'm not a hotshot. I'm just an expert on electric transport, I make transition models (NEONresearch.nl) and I've been showing for a while now that solar, wind, and EVs are underestimated.

https://twitter.com/AukeHoekstra/status/1333192375259295744

But I have a background in organisational science and...

I think it boils down to this:

Climate scientists are used to RCP 8.5:
- It's in all their models and they know it well
- It's useful for comparing model differences
- It extrapolates undisputed historical facts
- It gets attention

The media LOVES RCP 8.5:
- It's climate porn

Energy scientists HATE RCP 8.5:
- It denies every development of the past 30 years
- Solar and wind should immediately cease to exist and become much more expensive instead of cheaper
- Closing coal plants should quickly open again

To them it really is "bollox".

I'm an energy scientist so maybe I'm biased but the division of labor seems clear here:

1) Energy scientists predict how much fossil fuel humanity will burn and in turn they accept climate models

2) Climate scientists accept energy science inputs for their climate models

So I think it's a dereliction of duty on the part of climate scientists that they simply choose the inputs they like and ignore the inputs from their energy scientist colleagues. And it's hurting science, giving children nightmares, and politicians an easy way out.

About that last point: I understand you want politicians to get off their butts and do something. So scare stories are tempting.

But this is a marathon and faith in science getting it's facts right is important. Don't doubt for a moment people will attack science with SSP5-8.5.

Moreover there are many innovations (both in technology and behavior) that make emission reductions much easier than previously thought.

We should use the truth-telling powers of science to find out what's going right and force politicians to double down on that!

With SSP5-8.5 as business as usual politicians can lean back and say: it seems we have averted the worst of it!

In reality they just look good compared to a nonsensical scenario that was used for shock effect.

So please dear twitter: don't hate me for pointing out this @guardian story and the underlying study are based on climate scientists ignoring energy scientists.

Instead join me in spreading truth and forcing politicians to double down on what works.

We CAN turn this around!

To clarify: the main conclusion of the paper: "Increasing probability of record-shattering climate extremes" (they researched heat waves) is true in any scenario. Let's prepare for that.
I'm unhappy that they mainly used high-emission numbers and the @guardian left that fact out.

I would like to see more comparisons with SSP2-4.5: the "middle of the road" scenario in the upcoming IPCC report. But there's only one graph with ~that comparison: panel f in this main graph. Almost all other info is RCP 8.5 based.
nature.com/articles/s4155…

And finally: I'm NOT saying "Oh, alrighty then."

I think the realistic scenario is already scary as hell with small but significant (e.g. 9%?) chances of wiping out civilization. Let's not play Russian roulette.

But for the love of all that's dear: let's use the best science.