natural gas

new-research-shows-gas-stove-emissions-contribute-to-19,000-deaths-annually

New research shows gas stove emissions contribute to 19,000 deaths annually

New research shows gas stove emissions contribute to 19,000 deaths annually

Ruth Ann Norton used to look forward to seeing the blue flame that danced on the burners of her gas stove. At one time, she says, she would have sworn that preparing meals with the appliance actually made her a better cook.

But then she started learning about the toxic gasses, including carbon monoxide, formaldehyde and other harmful pollutants that are emitted by stoves into the air, even when they’re turned off.

“I’m a person who grew up cooking, and love that blue flame,” said Norton, who leads the environmental advocacy group known as the Green & Healthy Homes Initiative. “But people fear what they don’t know. And what people need to understand really strongly is the subtle and profound impact that this is having—on neurological health, on respiratory health, on reproductive health.”

In recent years, gas stoves have been an unlikely front in the nation’s culture wars, occupying space at the center of a debate over public health, consumer protection, and the commercial interests of manufacturers. Now, Norton is among the environmental advocates who wonder if a pair of recent developments around the public’s understanding of the harms of gas stoves might be the start of a broader shift to expand the use of electrical ranges.

On Monday, lawmakers in the California Assembly advanced a bill that would require any gas stoves sold in the state to bear a warning label indicating that stoves and ovens in use “can release nitrogen dioxide, carbon monoxide, and benzene inside homes at rates that lead to concentrations exceeding the standards of the Office of Environmental Health Hazard Assessment and the United States Environmental Protection Agency for outdoor air quality.”

The label would also note that breathing those pollutants “can exacerbate preexisting respiratory illnesses and increase the risk of developing leukemia and asthma, especially in children. To help reduce the risk of breathing harmful gases, allow ventilation in the area and turn on a vent hood when gas-powered stoves and ranges are in use.”

The measure, which moved the state Senate, could be considered for passage later this year.

“Just running a stove for a few minutes with poor ventilation can lead to indoor concentrations of nitrogen dioxide that exceed the EPA’s air standard for outdoors,” Gail Pellerin, the California assembly member who introduced the bill, said in an interview Wednesday. “You’re sitting there in the house drinking a glass of wine, making dinner, and you’re just inhaling a toxic level of these gases. So, we need a label to make sure people are informed.”

Pellerin’s proposal moved forward in the legislature just days after a group of Stanford researchers announced the findings of a peer-reviewed study that builds on earlier examinations of the public health toll of exposure to nitrogen dioxide pollution from gas and propane stoves.

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us’s-power-grid-continues-to-lower-emissions—everything-else,-not-so-much

US’s power grid continues to lower emissions—everything else, not so much

Down, but not down enough —

Excluding one pandemic year, emissions are lower than they’ve been since the 1980s.

Graph showing total US carbon emissions, along with individual sources. Most trends are largely flat or show slight declines.

On Thursday, the US Department of Energy released its preliminary estimate for the nation’s carbon emissions in the previous year. Any drop in emissions puts us on a path that would avoid some of the catastrophic warming scenarios that were still on the table at the turn of the century. But if we’re to have a chance of meeting the Paris Agreement goal of keeping the planet from warming beyond 2° C, we’ll need to see emissions drop dramatically in the near future.

So, how is the US doing? Emissions continue to trend downward, but there’s no sign the drop has accelerated. And most of the drop has come from a single sector: changes in the power grid.

Off the grid, on the road

US carbon emissions have been trending downward since roughly 2007, when they peaked at about six gigatonnes. In recent years, the pandemic produced a dramatic drop in emissions in 2020, lowering them to under five gigatonnes for the first time since before 1990, when the EIA’s data started. Carbon dioxide release went up a bit afterward, with 2023 marking the first post-pandemic decline, with emissions again clearly below five gigatonnes.

The DOE’s Energy Information Agency (EIA) divides the sources of carbon dioxide into five different sectors: electricity generation, transportation, and residential, commercial, and industrial uses. The EIA assigns 80 percent of the 2023 reduction in US emissions to changes in the electric power grid, which is not a shock given that it’s the only sector that’s seen significant change in the entire 30-year period the EIA is tracking.

With hydro in the rearview mirror, wind and solar are coming after coal and nuclear.

With hydro in the rearview mirror, wind and solar are coming after coal and nuclear.

What’s happening with the power grid? Several things. At the turn of the century, coal accounted for over half of the US’s electricity generation; it’s now down to 16 percent. Within the next two years, it’s likely to be passed by wind and solar, which were indistinguishable from zero percent of generation as recently as 2004. Things would be even better for them if not for generally low wind speeds leading to a decline in wind generation in 2023. The biggest change, however, has been the rise of natural gas, which went from 10 percent of generation in 1990 to over 40 percent in 2023.

A small contributor to the lower emissions came from lower demand—it dropped by a percentage point compared to 2022. Electrification of transport and appliances, along with the growth of AI processing, are expected to send demand soaring in the near future, but there’s no indication of that on the grid yet.

Currently, generating electricity accounts for 30 percent of the US’s carbon emissions. That places it as the second most significant contributor, behind transportation, which is responsible for 39 percent of emissions. The EIA rates transportation emissions as unchanged relative to 2022, despite seeing air travel return to pre-pandemic levels and a slight increase in gasoline consumption. Later in this decade, tighter fuel efficiency rules are expected to drive a decline in transportation emissions, which are only down about 10 percent compared to their 2006 peak.

Buildings and industry

The remaining sectors—commercial, residential, and industrial—have a more complicated relationship with fossil fuels. Some of their energy comes via the grid, so its emissions are already accounted for. Thanks to the grid decarbonizing, these would be going down, but for business and residential use, grid-dependent emissions are dropping even faster than that would imply. This suggests that things like more efficient lighting and appliances are having an impact.

Separately, direct use of fossil fuels for things like furnaces, water heaters, etc., has been largely flat for the entire 30 years the EIA is looking at, although milder weather led to a slight decline in 2023 (8 percent for residential properties, 4 percent for commercial).

In contrast, the EIA only tracks the direct use of fossil fuels for industrial processes. These are down slightly over the 30-year period but have been fairly stable since the 2008 economic crisis, with no change in emissions between 2022 and 2023. As with the electric grid, the primary difference in this sector has been due to the growth of natural gas and the decline of coal.

Overall, there are two ways to look at this data. The first is that progress at limiting carbon emissions has been extremely limited and that there has been no progress at all in several sectors. The more optimistic view is that the technologies for decarbonizing the electric grid and improving building electrical usage are currently the most advanced, and the US has focused its decarbonization efforts where they’ll make the most difference.

From either perspective, it’s clear that the harder challenges are still coming, both in terms of accelerating decarbonization, and in terms of tackling sectors where decarbonization will be harder. The Biden administration has been working to put policies in place that should drive progress in this regard, but we probably won’t see much of their impact until early in the following decade.

Listing image by Yaorusheng

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40%-of-us-electricity-is-now-emissions-free

40% of US electricity is now emissions-free

Decarbonizing, but slowly —

Good news as natural gas, coal, and solar see the biggest changes.

Image of electric power lines with a power plant cooling tower in the background.

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.

Let’s look at the year-to-date data to get a sense of the trends and where things stand. We’ll then check the monthly data for October to see if any of those trends show indications of reversing.

The most important takeaway is that energy use is largely flat. Overall electricity production year-to-date is down by just over one percent from 2022, though demand was higher this October compared to last year. This is in keeping with a general trend of flat-to-declining electricity use as greater efficiency is offsetting factors like population growth and expanding electrification.

That’s important because it means that any newly added capacity will displace the use of existing facilities. And, at the moment, that displacement is happening to coal.

Can’t hide the decline

At this point last year, coal had produced nearly 20 percent of the electricity in the US. This year, it’s down to 16.2 percent, and only accounts for 15.5 percent of October’s production. Wind and solar combined are presently at 16 percent of year-to-date production, meaning they’re likely to be in a dead heat with coal this year and easily surpass it next year.

Year-to-date, wind is largely unchanged since 2022, accounting for about 10 percent of total generation, and it’s up to over 11 percent in the October data, so that’s unlikely to change much by the end of the year. Solar has seen a significant change, going from five to six percent of the total electricity production (this figure includes both utility-scale generation and the EIA’s estimate of residential production). And it’s largely unchanged in October alone, suggesting that new construction is offsetting some of the seasonal decline.

Coal is being squeezed out by natural gas, with an assist from renewables.

Enlarge / Coal is being squeezed out by natural gas, with an assist from renewables.

Eric Bangeman/Ars Technica

Hydroelectric production has dropped by about six percent since last year, causing it to slip from 6.1 percent to 5.8 percent of the total production. Depending on the next couple of months, that may allow solar to pass hydro on the list of renewables.

Combined, the three major renewables account for about 22 percent of year-to-date electricity generation, up about 0.5 percent since last year. They’re up by even more in the October data, placing them well ahead of both nuclear and coal.

Nuclear itself is largely unchanged, allowing it to pass coal thanks to the latter’s decline. Its output has been boosted by a new, 1.1 Gigawatt reactor that come online this year (a second at the same site, Vogtle in Georgia, is set to start commercial production at any moment). But that’s likely to be the end of new nuclear capacity for this decade; the challenge will be keeping existing plants open despite their age and high costs.

If we combine nuclear and renewables under the umbrella of carbon-free generation, then that’s up by nearly 1 percent since 2022 and is likely to surpass 40 percent for the first time.

The only thing that’s keeping carbon-free power from growing faster is natural gas, which is the fastest-growing source of generation at the moment, going from 40 percent of the year-to-date total in 2022 to 43.3 percent this year. (It’s actually slightly below that level in the October data.) The explosive growth of natural gas in the US has been a big environmental win, since it creates the least particulate pollution of all the fossil fuels, as well as the lowest carbon emissions per unit of electricity. But its use is going to need to start dropping soon if the US is to meet its climate goals, so it will be critical to see whether its growth flat lines over the next few years.

Outside of natural gas, however, all the trends in US generation are good, especially considering that the rise of renewable production would have seemed like an impossibility a decade ago. Unfortunately, the pace is currently too slow for the US to have a net-zero electric grid by the end of the decade.

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