Last year, the Trump administration did what it could to shut down work on the next US National Climate Assessment, eliminating funding for the US Global Change Research Program and booting hundreds of contributing authors. The administration even took past reports offline, forcing others to host copies so the information would still be accessible. And this all comes despite the fact that these reports are legally required.

Later in the year, the American Geophysical Union and American Meteorological Society announced an effort to give researchers a central place to compile the kind of work that would have fed the next US report, as well as potential regional and local reports. This “US Climate Collection” works differently from the US Global Change Research Program or the International Panel on Climate Change (IPCC). Rather than facilitating the writing of a giant, coordinated report, the groups are inviting teams of researchers to publish peer-reviewed papers in scientific journals, which will then be added to a centralized resource for future report-writers.

The first paper has now been added to that collection. It’s the work of 175 authors (many of whom had been working on the US report), and it is actually being published in two journals—one operated by the American Geophysical Union and one by the American Meteorological Society. That’s because this paper is intended to provide a roadmap to prioritize future contributions.

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In one episode of the Hanna-Barbera cartoon Birdman, the eponymous hero struggles to fight the evil Dr. Shark aboard a submarine without solar energy to recharge his powers. So Birdman would surely appreciate the new perovskite solar cells developed by a team led by Simin Ma at Yunnan University, since they are designed to work underwater.

Solar cells made from perovskites rather than silicon are always a tale of trade-offs. They can be made cheaply, they can take interesting forms (like thin, flexible, transparent films), and they can convert substantially more of the incoming solar energy into electricity. The difficulty is that they tend to degrade quite quickly.

Tuned for the deep

Moisture is particularly destructive to perovskites, making them a seemingly odd choice for an underwater solar panel. But these materials have another critical superpower: They can be tuned to work with different wavelengths of light. Water quickly blocks the wavelengths of light that silicon solar panels absorb, but a carefully designed perovskite cell could still make electricity in the deep blue sea. And actually, the lower light levels and cooler temperatures should help it live longer.

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Google is one of the major players in AI (meaning machine learning) weather forecast model space. The models it and others generate have their strengths and weaknesses, but the main advantage is that they can have forecast performance similar to traditional models while requiring far less computing horsepower to run. That means they can be run more frequently.

Google recently released version 3 of its WeatherNext model, with the biggest change being that it now ingests some satellite weather data, shortening the lag time between current weather conditions and generating a new forecast. The update is detailed in a white paper.

Reanalysis

Many weather models make use of what’s called a “reanalysis,” which is a sort of model of its own. Reanalyses take in all kinds of weather data and combine them into a single, consistent global snapshot of the atmosphere. That requires that they provide estimates for conditions over locations without real-world measurements, because weather forecast models need to work with a global picture.

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Elon Musk’s talk about maintaining a million-strong AI data center satellite megaconstellation may not exactly be practical or economical, but it might be unique. It’s about the closest we’ve come to confronting a scheme that would export a considerable amount of valuable materials into space. Humans aren’t doing a great job of material sustainability, but normally we’re talking about stuff escaping a recycling pipeline rather than escaping Earth’s gravitational pull.

The commercial space sector likes talking about the allure of mining asteroids for precious metals to bring back to Earth. Under what circumstances are we going to be willing to do that in reverse? Starlink alone has doubled the mass of objects in low-Earth orbit, and this orbital data center constellation would dwarf that—and dispose of at least some satellites by pushing them away from Earth.

Given the roughly five-year expected lifetime for data center GPUs, about 200,000 of the 1 million proposed SpaceX AI1 satellites would be decommissioned each year. Based on their May 29 FCC filing, about 40,000 would definitely deorbit and burn up in the atmosphere. (Those materials would largely be dispersed throughout the atmosphere, turning a resource into a diffuse contaminant that slowly settles over the globe. One related issue: the aluminum would cause an unknown amount of ozone depletion over a period of decades.) Some or all of the remaining 160,000 satellites would be moved outward into a distant “disposal” orbit, instead. Either way, they're lost from a "material life cycle" point of view.

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Global warming is leading to more extremely hot weather. There is perhaps no more obvious consequence of climate change. But changing how we analyze this problem can still help scientists think about it in a different way that may yield surprises.

Generally, studies on heat extremes work with some combination of daily minimum, maximum, and mean temperatures. Sometimes they focus on multi-day heatwaves using those metrics, since the discomfort and health impacts increase for longer events. There are different thresholds you can use to define extreme heat in these analyses, either based on past statistics or on the human body’s physiological limits.

A new study led by Weilin Liao and Xuanzong Zhang at Sun Yat-sen University tried breaking down heat extremes to the hourly level instead, which reveals some interesting nuances.

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While recycling is a mathematically obvious response to the finite, non-renewable nature of many resources, the economic math is often challenging. For many materials, it can be hard to compete with virgin materials on a cost basis. Fast-moving technologies like electric vehicles throw in an added complication: By the time a car is scrapped, the industry may have moved on to a different battery chemistry. That reduces the value of recycling the car’s battery back into the production chain.

Still, a study led by Xin Xiong at Nanjing University finds that in China, recycling could become the dominant source of many key materials needed to manufacture EV components over the coming decades.

Modeling manufacturing needs

The researchers set out to model how the supply of recycled materials compares to manufacturing demand in China between 2010 and 2050. It covers materials relevant to batteries across hybrid, battery-electric, and even fuel-cell vehicles (lithium, cobalt, nickel, manganese, phosphorus, sodium, sulfur, and graphite), as well as several critical elements used in electric motors (copper, neodymium, dysprosium, samarium, and cerium).

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The ban on ozone-depleting substances that successfully reversed the growth of the hole in the ozone layer isn’t seen as a missed opportunity. On the contrary, the quick global response is one of the best cases of common-sense environmental action. But what if it could have been done even earlier?

The fact that chlorofluorocarbons (CFCs)—chemicals once common in aerosol cans and refrigerant loops—could destroy ozone in the atmosphere was discovered in 1974. Within just a few years, bans on CFCs began to roll out based on the projected consequences. The seasonal ozone “hole” discovered over Antarctica in 1985 pushed things along even faster, and in 1987 an international agreement was signed to phase out CFCs everywhere.

A new study led by Jian Guan at MIT asks an interesting what-if question: Would it have been possible to detect this problem even sooner with today’s scientific tools?

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