Tom Wood

@ryankatzrosene Agreed. Couldn't fit full response in single tweet, but I am equally (if not more) critical of the framing in the OP. I don't think your post overall is vague, but we need to be careful with language (OP included!). Stating its "deeply unlikely" swings from one extreme to other.

Taking a precautionary principle approach makes sense to me. But I think a social media post from a scientist saying societal collapse *will* occur over the next two dozen years is a lot more dangerous than a more “vague” post expressing the belief that the former seems deeply unlikely.

I think the preponderance of evidence suggests that this👇 - a societal collapse brought about by a collapse of global harvests before 2050 - is a deeply unlikely outcome. Look, I'm the first to call climate change an alarming problem for society. And, I live on a farm: Increases in agricultural drought and extreme rainfall - both of which have been observed in most regions of the world, and both of which are projected to increase due to global warming - are real and they suck and can seriously hamper a given operation's agricultural output for a year or longer (or even an entire region's). BUT: Agricultural output and yields are mediated by several factors, natural and human. Climate change is hampering crop *productivity* in several contexts (for specific regions, and specific crops), but it is also *increasing* output for some regional, some specific crops, and specific development contexts. We also have (truly!) incredible innovations and adaptations as a species when it comes to food production and distribution. And, thanks to global markets and substitutability (greater for some foods than others), and a somewhat existing (though admittedly highly dysfunctional and swiftly degrading) global development aparatus, humanity has shown that it can 'weather' - to an extent - agricultural output disruptions... The main points of evidence are: a) global average crop yields for key staples (soybeans, rice, maize and wheat) have grown *dramatically* (like, we're talking hundreds of percent increases) over the last half Century, and are projected to continue growing (though yes, such growth may be partly or even fully negated by climate impacts in some cases); b) the percentage of humans that are undernourished is much lower in our contemporary era than it's been likely since the start of the Industrial Revolution - when there was chronic hunger globally. 1 of every 2 people globally back then were undernourished, and famines were common... but global population did not collapse, it *increased*. And famines have massively decreased. Yes, there has been some very concerning backsliding in recent years with undernourishment in Africa - but this is more a political economic challenge than a climatic one; c) the human population reached a peak growth rate 50 years ago. The UN's medium projection expects global population to peak in about 50-60 years, at just over 10 billion. But other demographic institutes argue the UN's medium projection is likely too high. Both IIASA and IHME, for instance, have medium projections seeing a peak closer to 9.5 billion, after which the global number of humans declines by 2100. d) Total agricultural productivity has grown tremendously (yes, with dire ecological and climatic consequences) for decades (nearly a 4X increase over the last half Century), and that is expected to continue growing. When you factor it all together, a *more likely* story - by mid-Century at least - is not one of collapse. It's one of more food per capita, and a (moderately) larger global population facing greater ecosystems disruption and increasing volatility from climate-related supply shocks. If collapse or famine comes in the next 25 years, it's more likely to be from a failure of global governance, conflict/warfare and associated economic upheaval than from climate-induced crop failures (unless AMOC collapses). I'm not saying Bill's scenario is impossible. And I think it's important to consider such worst case outcomes. Just saying it's less likely imho than the outcome I've laid out above. My two cents as someone who spends a lot of time thinking of this every day as part of my job.

@theAGU @BoseProtik @li_thal1 Thank you

@TomWoodScience @BoseProtik @li_thal1 Hello! We're aware of login issues on agu.org affecting membership renewals. Our team is working on it, and we appreciate your patience. To support affected users, the abstract deadline is extended to Thursday, 31 July at 5 PM ET.

🚨 Last chance! #AGU25 abstract submissions are due 30 July! 💡 Don’t have research to present, but have a great presentation or panel idea? Submit a Science Exchange Session, a new pathway for contributions from individuals that highlight experiences, ideas, tools, or the latest technologies. ➡️ Learn more: lite.spr.ly/6004J2pQ

@BoseProtik @li_thal1 @theAGU Me too

@li_thal1 @theAGU Facing the same issue here.

@li_thal1 @theAGU Me too

@theAGU @theAGU Will you be extending the submission deadline if your site is still down this evening? I've been trying to login for the last 2 hours. Thanks!

🚨 Hurry! The abstract submission deadline is tomorrow. Now is the time to submit your abstract and ensure your research has a spot at #AGU25. 👉 Submit by 30 July: lite.spr.ly/6005J2pH

@Jolyon_Larson @ArnabDatta321 @nytopinion Well said

@ArnabDatta321 @nytopinion Being pragmatic about fossil fuels means leaving them in the ground. When your policy proposal is ascientific, it is no longer evidence-based. It’s just politics, and, while doing what is politically expedient may be easier, that does not mean that it is the right course.

Climate advocates might feel hopeless with Pres-elect Trump returning to the WH. They shouldn’t. I wrote about how to make progress for @nytopinion: 1. Focus on innovation and industrial strategy 2. Be pragmatic about fossil fuels 3. Expand the interests that gain from decarb

@resfoundation What is included in 'transport'?

£1 in every £5 spent by low-to-middle income households’ goes on rent. Alongside rising housing costs food insecurity has increased significantly. It is now three times its pre-pandemic levels, with 1-in-5 Britons in 2023 skipping meals or eating less.

Despite being a climate summit, COP is often held in countries that are putting their foot on the accelerator of environmental collapse. Last year's COP was held in Dubai, and climate scientist @TomWoodScience was shocked by the gap between rhetoric and reality.

Yet another depressing failure of COP is on the cards it seems.

An ERA5 animation showing the unprecedented November 2024 Typhoon outbreak in the Western Pacific Ocean. Just incredible.

“It was a screaming example of everything that is wrong with the attitude of society: the juxtaposition of hyper-consumerism, wholly reliant on fossil fuels, and vulnerable people [at the conference] screaming out to us, ‘Do something about this’ – and not being listened to."

We spoke about my experience at COP28 in Dubai. On the view from my hotel window: "On the right ... the Dubai Marina, full of fancy restaurants & supercars. On the left, stretching out...as far as the eye could see, one of the biggest natural gas plants in the world...

“A low risk [of really extreme warming] is not no risk. That risk exists. If that risk is so severe it’s going to be catastrophic or existential, policy makers need to be prepared.” One of the quotes from me in this excellent piece from @RTakver discussing the impact of #COP29.

Important new study shows that current climate models underestimate the human-caused slowing of the #AMOC (Atlantic Meridional Overturning Circulation), because they neglect freshwater influx from Greenland melt and other sources. /1 nature.com/articles/s4156…

@_alice_evans Describing generative AI as a "fad" is incredibly short sighted.

Should universities teach students how to use generative AI? Here is another academic’s critique👇 But if universities’ role is to skill students for labour market, we might consider employers’ preferences. I respect academics’ principles, but the costs may be born by students

The Paris Agreement is far from adequate, but its the best basis for international cooperation on the climate challenge we have. We must advocate for it to be upheld and strengthened against the current significant headwinds.

As we near #COP29, this needs to be front and centre of our thoughts. The plausibility of remaining under 1.5K is fading rapidly - we need to refocus on damage limitation and be aware of voices resigned to failure.

@James_BG But they don't show uncertainty bands on their figures and leave caveats for the footnotes. This should be up front and centre, and the massive downside / worst-case from using more credible damage functions IMO should be emphasised as the potential impact is so huge.

@TomWoodScience Yup. In fairness, they do acknowledge the huge uncertainties, but these exercises are always inherently deeply flawed.

This is already bleak af from the OBR, but also if you think 3C of warming will only deliver a 5% hit to GDP I have a Miami beachfront condo to sell you.

@James_BG Yet they say their numbers are based on 'credible studies'. A fall of 5% GDP in a 3C world is just not credible and there is a large and growing pile of evidence showing this. e.g. Studies using Nordhaus' damage functions should not be taken seriously.

In fairness to the OBR, it recognises this fact repeatedly throughout the report.

@ProfJeroenBergh @JKSteinberger You even refer to degrowth as being a "young field" yourself, by the way. Why nitpick? x.com/ProfJeroenBerg…

@ProfJeroenBergh @JKSteinberger First point really just semantics, but fine. Would be interesting to know if papers critical of the topic are more likely to include the name in the title. I'm not partisan. Limiting search to titles seems an unnecessary restriction leading to potentially unfair representation.

Not to brag, but having led a large project on degrowth, "Living Well Within Limits", which published 33 papers, roughly half of which were data analysis and modelling, only 1 would have qualified for the parameters of the study cited. This is not indicative of anything. 🤷‍♀️