Some people rightly asked what I'd say instead of @ClimateBen's claims

The following thread gives my one-tweet summary, then more details

I'm sure my summary is not perfect, but IMO it represents climate science better (and he mentioned scientists) https://twitter.com/richardabetts/status/1279731157920251904

Without deep emissions cuts starting now, models project global warming to reach 2°C in the 2040s or 2050s, maybe slightly earlier as an extreme case

This risks major yield reductions of some key crops in many regions. Adaptation could reduce risks, but this itself needs action

The timing of reaching 2°C depends largely on which model is used. Some warm faster than others

Risk assessment should account for earlier dates in the range, even if they're not the most likely

But "90% of scientists think 2C by ~2038" overstates it

https://www.ipcc.ch/site/assets/uploads/2018/02/WG1AR5_TS_FINAL.pdf

Predicting crop yields at 2°C is difficult

Yields could either increase of decrease depending on which crops and also how regional climates change

There's clearly risks of decreased yields of some key crops in the tropics, but much less risk elsewhere

https://esd.copernicus.org/articles/9/479/2018/esd-9-479-2018.pdf

It's worth noting that this study looks at rain-fed crops, not irrigated crops. Irrigation and other adaptations would increase resilience

Since crops are already grown in hotter countries today, temperate regions could adapt. Obvs this is less certain for already-hot countries!

I am not by any means dismissing the severe implications of reduced crop yields in the tropics. This could risk hunger for millions

But the phrase "humanity relies upon for decent survival" suggested a more existential-level threat, which IMO goes beyond the scientific evidence

The @IPCC_CH 1.5C report discusses impacts on crop production at 1.5°C & 2°C in section 3.4.6.1

The story is complicated. One issue is whether CO2 fertilisation is important or not

Risks are clear, but "humanity" and "decent survival" are not mentioned

https://www.ipcc.ch/site/assets/uploads/sites/2/2019/06/SR15_Chapter3_Low_Res.pdf

To be fair to @ClimateBen, after I tweeted him earlier he did come back with a less extreme version of his statement

His "likely" statement is reasonable in relation to current policies

I just wish he'd said something more like that in the first place! https://twitter.com/ClimateBen/status/1279749561523802113

I do think more focus on risk assessment approaches is needed, not just central estimates

But even then, claims should still be scientifically valid

It's hard to put across complex messages in a single tweet. I'm sure there are better ways than I said it too

Lets keep talking!