There may be 4000 more minerals in the world than previously thought, according to a new catalogue that identifies them not only by their internal make-up, but by the ways they are formed.

at Yale University in Connecticut, who was not involved in the work, says the findings help make sense of Earth’s development, which researchers are finding is increasingly complex. “It is a welcome stepping stone in putting order in our knowledge. In the great scheme of things, nature doesn’t care, but we do, because by doing so, we can make sense of it,” he says.

Minerals are typically distinguished by their unique structure and chemistry. But because each mineral holds information about the Earth from when the rock was formed, the study authors say, focusing on the origin of minerals can better serve the study of the emergence of life and the evolution of planets.

“Minerals are essentially time capsules that lock in their formational conditions and the subsequent weathering and alteration that they underwent,” says at the Carnegie Institution for Science in Washington, DC.

Isolated by the covid-19 pandemic, she and her colleague immersed themselves in thousands of scientific papers, reference books and databases to identify the ways all the known minerals on Earth are formed. When minerals could form in different ways, they categorised them as distinct, increasing the total number of kinds of minerals.

The Carnegie researchers found that minerals could be formed in 57 different ways, such as asteroid collisions, evaporation or oxidation. Microorganisms also can leave behind metal deposits when they take specific elements for themselves, or when they separate compounds in search of a burst of electrical energy. These classifications allow mineralogists to concentrate their questions on the patterns across minerals, in a nascent discipline called mineral informatics.

Most minerals form in just one of these ways, while nine can be formed in more than 15 different ways. Pyrite, or fool’s gold, has come from 21 distinct origins, the most of any mineral. Water plays a central role in forming nearly half of Earth’s minerals, and biological life such as animals and microbes are required to form a third of Earth’s known minerals.

“Not only did minerals play a strong role in the origin of life, but life played a strong role in the origin of minerals,” says Hazen.

Based on their findings, she and Morrison suggest an expansion of the number of known minerals from under 6000 to more than 10,000.

They made their work available in a public database, which they say can help us use rocks to understand the evolution of Earth and other planets. Some theories about the origin of life, for example, assume that certain clays were on Earth at a certain time. Mineral evolution, as this field is called, uses what we know about mineral formation to find out whether those clays were really there and what kinds of life they may have bred.

“We use biology to study Earth’s past, but in the future, we can also use minerals to study Earth’s history,” says at Peking University in China, who also serves as the president of the International Mineralogical Association. He says this effort to classify minerals based on their origins is comparable to the creation of the periodic table of elements 150 years ago.

Hazen and Morrison say mineralogy could also have insights for Earth’s future. As the earth warms and sea ice melts, higher carbon in the atmosphere may encourage the development of minerals that contain more carbon, and changing water flows could lead to more diverse minerals at latitudes where they haven’t been recorded before.

In a sample of eagles from across the US, rat poison was found in about 80 per cent of the birds. This widespread exposure to toxic chemicals could impair their health or even lead to death.

“This really suggests that despite the best efforts to use these compounds wisely and minimise the opportunity for the raptor species to be exposed, they’re still somehow getting exposed,” says Mark Ruder at the University of Georgia.

Between 2014 and 2018, Ruder and his team determined the cause of death for 303 golden eagles (Aquila chrysaetos) and bald eagles (Haliaeetus leucocephalus), which were sent to them from around the US. Some deaths couldn’t be explained, but the team determined that 4 per cent of the eagles died directly as a result of rat poison.

They tested 133 of the birds for anticoagulant rodenticide, the most common rodenticide, which can also target opossums and beavers, and found that 82 per cent of the birds had it in their body.

There was a high prevalence of what are known as second-generation anticoagulant rodenticides, which are highly toxic and can remain active for months after ingestion. These have been tightly regulated by the US Environmental Protection Agency since 2011 and are only available for commercial use.

Eagles often scavenge, and rodents killed by the poison could become their food, although it still isn’t clear how exactly the eagles came into contact with it. It is also unclear whether the poison can affect reproduction or impair their health in other ways, says Ruder.

“Such widespread exposure indicates that this issue is more than a localised phenomenon, and if there are widespread health impacts they may occur throughout the population,” says Garth Herring at the US Geological Survey, who wasn’t involved in the study.

The findings are “alarming”, Ruder says, particularly because eagles and other raptors have recently rebounded from the brink of extinction caused by another toxic pesticide, DDT, which caused the birds to produce thin-shelled eggs. The threat of rodenticide may be exacerbated when combined with lead and bromide poisoning, which has also been documented in eagles.

“There is clearly widespread exposure of bald and golden eagles to these compounds, and whether it was directly causal in their death or not, the high prevalence that we found speaks to the potential,” he says.

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Hay fever season has become longer and more intense in North America over the past 30 years, thanks to the way plants are responding to climate change.

“This is an in-our-backyard example of climate change affecting us and human health already,” says William Anderegg at the University of Utah. “It’s not something that’s in the future or decades away.”

He and his colleagues analysed data from 60 long-term pollen-count stations around the continent, which recorded pollen in the air on sheets of sticky paper from 1990 to 2018. They found that over that time, pollen seasons have lengthened by roughly 10 days, and the amount of pollen in the air has grown by 21 per cent.

They defined the pollen season in a given area as the time during which pollen concentrations exceeded the 30th percentile in relation to the data from other pollen stations. Their analysis found that hotter weather can account for half of the extension in pollen seasons, and 8 per cent of the increase in pollen concentrations.

Warmer temperatures signal to plants that it is time to reproduce, leading to pollen seasons that typically start in the spring. Longer periods of high temperatures extend the time for pollination.

The rise in pollen concentration with every season isn’t as well understood. The jump may be due to the longer growing period itself, or to a combination of more carbon dioxide and higher temperatures that makes it easier for plants to photosynthesise, says Anderegg. With more carbon and more energy, plants can invest more in pollen, says Anderegg.

Surprisingly, he says, the greatest increases in pollen were seen in the south-eastern and mid-western US, even though temperatures are rising faster further north.

On the whole, pollen season may become less predictable, as both high temperatures and droughts become more common, says Anderegg.

“In the next decade or two, we probably expect the average pollen year to be getting worse, as we see in the trends in our study. But it’s very possible that the variation and year-to-year bounces could go up as well,” he says.

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Widening wealth gaps in some of the richest cities in the US have produced a rise in the number of households without running water.

Public information suggests that about half a million households in the US – about 1.1 million people – live without piped water, which places them in “plumbing poverty”. Surveys also show that 73 per cent of these households are found in metropolitan areas.

To investigate further, Katie Meehan at King’s College London – previously at the University of Oregon – and her colleagues analysed US census data, and information relating to the country’s 50 largest metropolitan areas collected during the government’s between 2013 and 2017.

This showed that San Francisco in California, Portland in Oregon and Austin in Texas are among the cities with the highest rates of plumbing poverty. New York, Los Angeles and San Francisco – among the wealthiest US cities – recorded the most overall residents without complete plumbing.

Meehan and her colleagues say there is a strong connection between this plumbing poverty and growing income inequality in cities.

They found that for every 10 per cent increase in income inequality in the 50 largest metropolitan areas, measured using a standard statistical metric called the , households were 1.5 times more likely to lack “complete plumbing” – defined as a house supplied by both hot and cold piped water with a bath or shower used only by the occupants.

“In areas that are characterised by income inequality, we see some of the highest rates of plumbing poverty,” says Meehan.

What’s more, people without access to piped water were significantly more likely to be living in rented accommodation and to be using more than of a third of their income to pay rent.

Urban households headed by black people were almost 35 per cent more likely to lack piped water compared with households headed by non-Hispanic white people.

Although surveys suggest that there are almost half a million US households without water access, Meehan says this is likely to be an undercount, because census surveys routinely have trouble recording renters, the homeless, and black people.

“I think that conditions of water access will actually deteriorate, and the places where I think it will get worse are not the places we may first think of, like the San Franciscos, the Portlands or the Los Angeleses,” she says.

Focusing on individual cities and households will help reveal what exactly is causing water insecurity, says Meehan. “That’s the next step in research.”