Geoengineering Hits Reality, and Your Body’s Hidden Sense Is Finally Getting Its Due

Let’s be honest: solar geoengineering has always sounded like a sci-fi fix for a very real mess. The idea that we could deliberately tweak the atmosphere to cool the planet—by spraying reflective particles or brightening clouds—has been debated for years, mostly in theory and computer models. But now, researchers are actually trying to build the stuff needed to make it happen. And surprise: it’s not going to be easy.

James Temple over at MIT Technology Review lays out the sobering details. The folks working on aircraft, materials, and delivery systems for solar geoengineering are discovering that even a modest deployment would require massive new infrastructure. We’re talking custom planes, specialized nozzles, and a supply chain for the particles themselves. This isn’t something you can just throw together with off-the-shelf parts. It’s a multi-year, multi-billion dollar undertaking before you even get to the ethical and governance nightmares.

I’ve always been skeptical of geoengineering as a quick fix—it feels like we’re borrowing trouble from the future. But this reality check is actually refreshing. It forces us to confront the scale of the problem and the limits of techno-optimism. If we’re going to do this, we need to do it right, not just fast. And maybe that’s the real lesson: the engineering challenges are a reminder that there are no shortcuts in climate action.

Meanwhile, on a completely different front, Katherine W. Isaacs dives into interoception—the science of how we sense our own bodies from the inside. This isn’t just about feeling your heartbeat or knowing when you’re hungry. It’s a whole hidden sense that’s been largely ignored until recently. A 2021 Nobel Prize in Physiology or Medicine went to David Julius and Ardem Patapoutian for their work on receptors for temperature and touch, which sparked a wave of interest in internal signaling pathways.

Now, with new tools like functional MRI and advanced biosensors, researchers are mapping how signals travel between the body and the brain. The implications are huge. Conditions like obesity, anxiety, and even chronic pain might be linked to disrupted interoception. If you can’t accurately sense your own hunger or stress, how do you regulate eating or calm down? It’s a fascinating angle that could shift how we treat mental and physical health.

The article is also the latest to be turned into an MIT Technology Review Narrated podcast, which is available on Spotify and Apple Podcasts. I’ve listened to a few of these, and they’re solid—well-produced and not too dry. Worth a listen if you’re commuting or just want a break from reading.

The must-reads from around the web

I skimmed the usual suspects so you don’t have to. Here’s what caught my eye:

• SpaceX is now valued higher than Amazon, hitting $2.659 trillion yesterday. That’s a wild milestone, though post-IPO stock swings briefly pushed it past Microsoft too. It’s now the fifth most valuable company globally. Oh, and they’re acquiring AI coding startup Cursor for $60 billion. That’s a lot of zeros, but it signals they’re serious about integrating AI into their operations.

• G7 leaders are pushing for access to top US AI models, trying to escape restrictions on models like Fable 5. There’s a global scramble for sovereign AI after the Mythos shutdown, and countries are looking to ditch US AI models entirely. This is a trend I’ve been watching—everyone wants their own AI, but building it from scratch is hard.

• Trump’s AI export strategy is running into his own export controls. It’s a classic case of policy contradictions: his administration wants to promote US AI dominance abroad, but the same controls are stifling the flow of technology. They’ve effectively created a licensing regime for frontier AI, which is bureaucratic and slow.

• Huawei’s big comeback shows the limits of US chip controls. They’ve managed to overcome restrictions on advanced chipmaking gear, which is a blow to the narrative that sanctions can completely isolate a determined player. The AI boom has only accelerated their efforts.

There’s more, but that’s the meat of it. The geoengineering piece is a must-read for anyone who thinks we can just hack the climate without consequences. And the interoception stuff? It’s a reminder that the most profound discoveries are often about things we take for granted—like the feeling of being alive.