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California's electric grid, with its massive solar production and booming battery installations, is already on the cutting edge of the US' energy transition. And it's likely to stay there, as the state will require that all passenger vehicles be electric by 2035. Obviously, that will require a grid that's able to send a lot more electrons down its wiring and a likely shift in the time of day that demand peaks.

Is the grid ready? And if not, how much will it cost to get it there? Two researchers at the University of California, Davis—Yanning Li and Alan Jenn—have determined that nearly two-thirds of its feeder lines don't have the capacity that will likely be needed for car charging. Updating to handle the rising demand might set its utilities back as much as 40 percent of the existing grid's capital cost.

The lithium state

Li and Jenn aren't the first to look at how well existing grids can handle growing electric vehicle sales; other research has found various ways that different grids fall short. But they have access to uniquely detailed data relevant to California's ability to distribute electricity (they do not concern themselves with generation). They have information on every substation, feeder line, and transformer that delivers electrons to customers of the state's three largest utilities, which collectively cover nearly 90 percent of the state's population. In total, they know the capacity that can be delivered through over 1,600 substations and 5,000 feeders.

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Almost from the start, arguments about mitigating climate change have included an element of cost-benefit analysis: Would it cost more to move the world off fossil fuels than it would to simply try to adapt to a changing world? A strong consensus has built that the answer to the question is a clear no, capped off by a Nobel in Economics given to one of the people whose work was key to building that consensus.

While most academics may have considered the argument put to rest, it has enjoyed an extended life in the political sphere. Large unknowns remain about both the costs and benefits, which depend in part on the remaining uncertainties in climate science and in part on the assumptions baked into economic models.

In Wednesday's edition of Nature, a small team of researchers analyzed how local economies have responded to the last 40 years of warming and projected those effects forward to 2050. They find that we're already committed to warming that will see the growth of the global economy undercut by 20 percent. That places the cost of even a limited period of climate change at roughly six times the estimated price of putting the world on a path to limit the warming to 2° C.

Enlarge / An oil refinery in Louisiana. Facilities such as this have led to a proliferation of petrochemical plants in the area. (credit: Art Wager )

On Tuesday, the US Environmental Protection Agency announced new rules that are intended to cut emissions of two chemicals that have been linked to elevated incidence of cancer: ethylene oxide and chloroprene. While production and use of these chemicals takes place in a variety of locations, they're particularly associated with an area of petrochemical production in Louisiana that has become known as " Cancer Alley ."

The new regulations would require chemical manufacturers to monitor the emissions at their facilities and take steps to repair any problems that result in elevated emissions. Despite extensive evidence linking these chemicals to elevated risk of cancer, industry groups are signaling their opposition to these regulations, and the EPA has seen two previous attempts at regulation set aside by courts.

Dangerous stuff

The two chemicals at issue are primarily used as intermediates in the manufacture of common products. Chloroprene, for example, is used for the production of neoprene, a synthetic rubber-like substance that's probably familiar from products like insulated sleeves and wetsuits. It's a four-carbon chain with two double-bonds that allow for polymerization and an attached chlorine that alters its chemical properties.

Enlarge / Mining operations start right at the edge of Bulqizë, Albania. (credit: Wikimedia Commons )

“The search for geologic hydrogen today is where the search for oil was back in the 19th century—we’re just starting to understand how this works,” said Frédéric-Victor Donzé, a geologist at Université Grenoble Alpes. Donzé is part of a team of geoscientists studying a site at Bulqizë in Albania where miners at one of the world’s largest chromite mines may have accidentally drilled into a hydrogen reservoir.

The question Donzé and his team want to tackle is whether hydrogen has a parallel geological system with huge subsurface reservoirs that could be extracted the way we extract oil. “Bulqizë is a reference case. For the first time, we have real data. We have a proof,” Donzé said.

Greenish energy source

Water is the only byproduct of burning hydrogen, which makes it a potential go-to green energy source. The problem is that the vast majority of the 96 million tons of hydrogen we make each year comes from processing methane, and that does release greenhouse gases. Lots of them. “There are green ways to produce hydrogen, but the cost of processing methane is lower. This is why we are looking for alternatives,” Donzé said.

Enlarge / With color, high resolution. (credit: Google/EDF)

When discussing climate change, attention generally focuses on our soaring carbon dioxide emissions. But levels of methane have risen just as dramatically, and it's a far more potent greenhouse gas. And, unlike carbon dioxide, it's not the end result of a valuable process; methane largely ends up in the atmosphere as the result of waste, lost during extraction and distribution.

Getting these losses under control would be one of the easiest ways to slow down greenhouse warming. But tracking methane emissions often comes from lots of smaller, individual sources. To help get a handle on all the leaks, the Environmental Defense Fund has been working to put its own methane-monitoring satellite in orbit. On Wednesday, it announced that it was partnering with Google to take the data from the satellite, make it publicly available, and tie it to specific sources.

The case for MethaneSAT

Over the course of 20 years, methane is 84 times more potent than carbon dioxide when it comes to greenhouse warming. And most methane in the atmosphere ultimately reacts with oxygen, producing water vapor and carbon dioxide—both of which are also greenhouse gasses. Those numbers are offset by the fact that methane levels in the atmosphere are very low, currently just under two parts per million (vs. over 400 ppm for CO ₂ ). Still, levels have gone up considerably since monitoring started.

Enlarge / It takes a lot of energy to keep pumping out more bitcoins. (credit: Andriy Onufriyenko )

What exactly is bitcoin mining doing to the electric grid? In the last few years, the US has seen a boom in cryptocurrency mining, and the government is now trying to track exactly what that means for the consumption of electricity. While its analysis is preliminary, the Energy Information Agency (EIA) estimates that large-scale cryptocurrency operations are now consuming over 2 percent of the US's electricity . That's roughly the equivalent of having added an additional state to the grid over just the last three years.

Follow the megawatts

While there is some small-scale mining that goes on with personal computers and small rigs, most cryptocurrency mining has moved to large collections of specialized hardware. While this hardware can be pricy compared to personal computers, the main cost for these operations is electricity use, so the miners will tend to move to places with low electricity rates. The EIA report notes that, in the wake of a crackdown on cryptocurrency in China, a lot of that movement has involved relocation to the US, where keeping electricity prices low has generally been a policy priority.

One independent estimate made by the Cambridge Centre for Alternative Finance had the US as the home of just over 3 percent of the global bitcoin mining at the start of 2020. By the start of 2022, that figure was nearly 38 percent.

Some of the microbes that make carbon sequestration work. (credit: Andes Ag, Inc)

In 2022, humans emitted a staggering 36 gigatons of carbon dioxide into the atmosphere. Along with reducing emissions, removing carbon dioxide from the atmosphere is a key climate mitigation strategy. But Gonzalo Fuenzalida wasn’t looking to help solve climate change when he co-founded the company Andes .

“We started this company with the idea of using microbes to make the process of growing food more resilient,” says Fuenzalida. “We stumbled upon these microbes that have the ability to create minerals in the soil which contain carbon and that intrigued us.”

Fuenzalida, alongside his co-founder Tania Timmermann-Aranis, had an unconventional notion: They could harness the power of microbes residing in plant roots within the soil to remove carbon from the atmosphere. These naturally occurring microbes can be applied to the soil by blending them with pesticides or other soil treatments—they will strategically position themselves within the root structure of corn, wheat, and soy plants.

Enlarge (credit: Bruce Yuanyue Bi )

A few years back, the Internet was abuzz with the idea of vertical farms running down the sides of urban towers, with the idea that growing crops where they're actually consumed could eliminate the carbon emissions involved with shipping plant products long distances. But lifecycle analysis of those systems, which require a lot of infrastructure and energy, suggest they'd have a hard time doing better than more traditional agriculture.

But those systems represent only a small fraction of urban agriculture as it's practiced. Most urban farming is a mix of local cooperative gardens and small-scale farms located within cities. And a lot less is known about the carbon footprint of this sort of farming. Now, a large international collaboration has worked with a number of these farms to get a handle on their emissions in order to compare those to large-scale agriculture.

The results suggest it's possible that urban farming can have a lower impact. But it requires choosing the right crops and a long-term commitment to sustainability.

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Just before the holiday break, the US Energy Information Agency released data on the country's electrical generation. Because of delays in reporting, the monthly data runs through October, so it doesn't provide a complete picture of the changes we've seen in 2023. But some of the trends now seem locked in for the year: wind and solar are likely to be in a dead heat with coal, and all carbon-emissions-free sources combined will account for roughly 40 percent of US electricity production.

Tracking trends

Having data through October necessarily provides an incomplete picture of 2023. There are several factors that can cause the later months of the year to differ from the earlier ones. Some forms of generation are seasonal—notably solar, which has its highest production over the summer months. Weather can also play a role, as unusually high demand for heating in the winter months could potentially require that older fossil fuel plants be brought online. It also influences production from hydroelectric plants, creating lots of year-to-year variation.

Finally, everything's taking place against a backdrop of booming construction of solar and natural gas. So, it's entirely possible that we will have built enough new solar over the course of the year to offset the seasonal decline at the end of the year.