"Simultaneous harvest failures across major crop-producing regions are a threat to global food security... Here we find an increased likelihood of concurrent low yields during summers featuring meandering jets in observations and models... Given the identified model biases, future assessments of regional and concurrent crop losses from meandering jet states remain highly uncertain."
"Concurrent crop failures in major crop-producing regions constitute a systemic risk as associated spikes in food prices can lead to conflict and undernutrition in countries that rely on imports... We find that simultaneous extremes linked to a meandering jet stream from amplified Rossby waves19 lead to regional yield losses... and to concurrent low harvests across the mid-latitudes... This increased likelihood of concurrent low yields in major breadbaskets, is mostly reproduced by historical model experiments, whether driven by reanalysis data or climate models in particular."
If people are not aware, the jetstreams meandering (Rossby waves) over western continental US have stay put (i.e., have not migrated, or diminished, or collapsed) over the last month.They now engulf almost the entirety of continental US, and predictions say that it will continue to stay put over the entire summer.
Let's also not forget, as of now, even without concurrent crop failures as detailed in the paper, as the World Food Programme, FAO and IFPRI have reported, currently 350 million people worldwide are acutely food insecure, with a further 2 billion within the category of being precarious when it comes to food security.
For a news version of this paper including identifying the primary suspects, the politics, why there is hardly any media coverage, and why this is possibly the only thing we should be talking about, here is George Monbiot writing in The Guardian:
"It could scarcely be more screwed up. The effort to protect Earth systems and the human systems that depend on them is led by people working at the margins with tiny resources, while the richest and most powerful use every means at their disposal to stop them. Can you imagine, in decades to come, trying to explain this to your children?"