Carbon dioxide (CO2) is a key driver of global climate change and the ability to monitor human-based emissions of this gas is crucial for quantifying the effectiveness of carbon-reduction policies. In recent years, space-based platforms like the Orbiting Carbon Observatory (OCO-2 and OCO-3) missions have provided atmospheric CO2 observations with near-global coverage and efforts to ingest these data into local, regional, and national carbon accounting methodologies have been successful. However, space-based observations are influenced by physical and environmental factors that affect their coverage.
Roten and Chatterjee [2025] investigate these factors and determine that the time needed to constrain emissions varies among cities within the United States. Key factors that affect these space-based platforms include the type of orbit they are in, the location of clouds in Earth’s atmosphere, and the distribution of atmospheric aerosols. The characteristics of the instruments’ orbits also vary the frequency of urban observations in both space and time. Results show that cities on the west coast are more frequently observed than cities in the northeast. These limitations should be considered when cities are seeking to monitor their emission reduction efforts with space-based technologies.
Predicted mean effective revisit time (τ) values from the Orbiting Carbon Observatory are spatially distributed at a 1km × 1km resolution across CONUS. White points indicate the locations of target cities and their sizes represent the mean CO2 emitted from each city during time interval τ. Much of the west had τ values short enough to facilitate sub-monthly observations; conversely, much of the northeast could not be constrained at such a scale (τ > 30 days). Credit: Roten and Chatterjee [2025], Figure 7
Citation: Roten, D., & Chatterjee, A. (2025). Coverage-limiting factors affecting the monitoring of urban emissions with the orbiting carbon observatory missions. AGU Advances, 6, e2024AV001630. https://doi.org/10.1029/2024AV001630
Research & Developments is a blog for brief updates that provide context for the flurry of news regarding law and policy changes that impact science and scientists today.
On 11 June, the Environmental Protection Agency announced a proposal to repeal federal limits on power plant carbon emissions, including a Biden-era rule requiring power plants to control 90% of their carbon pollution and a 2015 standard limiting carbon dioxide emissions from new fossil fuel-fired power plants.
If made final, the plans mean that coal, oil, and gas-powered plants in the United States will no longer need to comply with federal limits on carbon dioxide emissions.
In the announcement, the agency argued that carbon emissions “are global in nature,” so any of their potential public health harms are not able to be accurately attributed to emissions from the United States. However, the U.S. power sector ranks among the world’s largest sources of carbon pollution, and emissions from the U.S. power sector already contribute to billions of dollars in global health damages, according to a report from the Institute for Policy Integrity.
The carbon pollution standards that the EPA aims to erase “have been criticized as being designed to regulate coal, oil and gas out of existence,” EPA administrator Lee Zeldin said in a statement. “According to many, the primary purpose of these Biden-Harris administration regulations was to destroy industries that didn’t align with their narrow-minded climate change zealotry.”
The Associated Press estimates that the Biden-era carbon pollution limits could prevent up to 30,000 premature deaths each year.
“By giving a green light to more pollution, [Zeldin’s] legacy will forever be someone who does the bidding of the fossil fuel industry at the expense of our health,” Gina McCarthy, a former EPA administrator, told the New York Times.
The announcement comes a day after Jarrod Agen, an energy advisor to President Trump and executive director of the White House’s National Energy Dominance Council, reaffirmed the administration’s intention to re-focus U.S. energy production on coal and natural gas.
“The president’s priorities are around turning around fossil fuels,” Agen said, adding that President Trump “is not focused on wind and solar.”
In the same announcement, the EPA also proposed the removal of a rule known as the Mercury and Air Toxics Standards, which tightened emissions of mercury and other toxic metals from power plants. Documents outlining Zeldin’s plans for the mercury rule, reviewed by the New York Times, said the Biden administration “improperly targeted coal-fired power plants” when it created the original rule.
These updates are made possible through information from the scientific community. Do you have a story about how changes in law or policy are affecting scientists or research? Send us a tip at [email protected].
Great apes began to diverge from other primates around 25 million years ago, according to eastern African fossil records. Though it would take another 20 million or so years for upright-walking hominins to appear, understanding the habitats of early apes helps clarify how environments drove the evolution of our distant ancestors.
Munyaka et al. excavated and analyzed fossils from an approximately 20-million-year-old early Miocene site in western Kenya called Koru 16. The now-extinct Tinderet Volcano repeatedly blanketed the area in ash, preserving it for millions of years, and today, the site hosts fossils from an array of plants and animals.
Many prior studies focused on the area around Koru 16: The first primate fossils from the site were discovered in 1927, and famed anthropologist Louis Leakey led multiple digs there.
As part of the new research, scientists uncovered fossils of approximately 1,000 leaves and many vertebrates at two subsites between 2013 and 2023. The specimens included those of a new type of large-bodied ape and two other previously known ape species, bringing the total number of vertebrate species discovered at the site to 25.
By examining the shapes of fossilized leaves, the geochemistry of fossilized soils (paleosols), and the distribution and density of fossil tree stumps, the researchers determined that the Koru 16 site was likely located within a warm, wet forest, with rainfall amounts similar to those of modern-day tropical and seasonal African forests. However, the ancient ecosystem likely hosted more deciduous plants than do modern tropical forests. The vertebrate fossils the researchers analyzed were consistent with apes, pythons, and rodents that might have lived in such an environment.
The researchers suggest that this ancient forest environment—which was interspersed with open areas and frequently disturbed by fires, floods, or volcanic eruptions—played a role in shaping the course of evolution for early apes. (Paleoceanography and Paleoclimatology, https://doi.org/10.1029/2025PA005152, 2025)
—Madeline Reinsel, Science Writer
Citation: Reinsel, M. (2025), Early apes evolved in tropical forests disturbed by fires and volcanoes, Eos, 106, https://doi.org/10.1029/2025EO250221. Published on 12 June 2025.
On 17 May 2025, a failure occurred in a mine waste facility at the Tawau gold mine in Malaysia. Images suggest that this might have been an overtopping event in a contaminated water storage pond.
The event occurred at a gold mine at Bukit Mantri, which is located at [4.5095, 118.1094]. Reports suggest that a tailings dam or water retention dam failed on 17 May 2025. There is reportedly a video that captured the event, although I have been unable to track this down. The still below, posted in a report by Tuhua Bambangan, reportedly shows the event:-
The Planet Labs satellite image below shows the mine site at Bukit Mantri, captured two days before the failure on 15 May 2025. I have circled the most likely location of the failure:-
Satellite image of the Bukit Mantri mine site before the mine waste storage facility failure. Image copyright Planet Labs, used with permission. Image dated 15 May 2025.
The image below was captured on 25 May 2025, eight days after the failure:-
Satellite image of the Bukit Mantri mine site after the mine waste storage facility failure. Image copyright Planet Labs, used with permission. Image dated 25 May 2025.
And here is a slider to compare the two images:-
Before and after Planet Labs images of the possible location of the Bukit Mantri wine waste failure.
I think the break in the dam is probably just visible, with some sediment deposited on the downstream side, although a higher resolution is needed for certainty.
“A subsidiary of Alumas Resource Berhad has been identified as currently conducting illegal gold mineral mining operations in Bukit Mantri, Balung Tawau.”
I have repeatedly written about mine waste failures over the years. It is depressing that 2025 has, to date, been a bumper year for such events.
Acknowledgements
Thanks to loyal reader Steven for spotting this event, and to Planet Labs for their amazing images.
Planet Team. 2024. Planet Application Program Interface: In Space for Life on Earth. San Francisco, CA. https://www.planet.com/
James Evans believes we’re training AI to think too much like humans—and it’s holding science back.
In this episode of the Big Brains podcast, Evans, a University of Chicago sociologist and data scientist, shares how our current models risk narrowing scientific exploration rather than expanding it.
He also digs into why he’s pushing for AIs that think differently from us—what he calls “cognitive aliens.”
Could these “alien minds” help us unlock hidden breakthroughs? And what would it take to build them?
A brain-to-voice neuroprosthesis enables a man with amyotrophic lateral sclerosis to synthesize his voice in real time by decoding neural activity, demonstrating the potential of brain–computer interfaces to enable people with paralysis to speak intelligibly and expressively.
Ancient carbon thought to be safely stored underground for millennia is unexpectedly resurfacing literally. A sweeping international study has found that over half of the carbon gases released by rivers come from long-term, old carbon sources like deep soils and weathered rocks, not just recent organic matter. This surprising discovery suggests Earth s vegetation is playing an even bigger role in absorbing excess carbon to keep the climate in check.
In a bold challenge to silicon s long-held dominance in electronics, Penn State researchers have built the world s first working CMOS computer entirely from atom-thin 2D materials. Using molybdenum disulfide and tungsten diselenide, they fabricated over 2,000 transistors capable of executing logic operations on a computer free of traditional silicon. While still in early stages, this breakthrough hints at an exciting future of slimmer, faster, and dramatically more energy-efficient electronics powered by materials just one atom thick.
