Climate Change Is Helping Fuel an Urban Rat Boom
Milder winters across the Northern Hemisphere are helping rats thrive in ever denser metropolitan areas. Just a handful of warmer weeks a year in a bustling city is enough to boost rodent population growth over time, according to the study.
'That's potentially two to four extra weeks a year that they can be above ground, foraging for food, acquiring those resources that they need to actually reproduce,' said Jonathan Richardson, an assistant professor of biology at the University of Richmond and lead author of the study.
A ballooning rodent population has the potential to create added headaches for public officials already fighting infestations. Rats can damage urban infrastructure and act as a vector for disease. They also take 'a measurable toll' on the mental health of people coexisting with them, according to the study. And there's an economic cost — cities across the globe are already spending $500 million each year to try and keep the rats at bay. In New York, for example, Mayor Eric Adams has declared a ' war on rats,' appointed a rat czar tasked with rodent mitigation efforts and hosted the city's first-ever National Urban Rat Summit.
Urban centers that saw larger increases in temperature over the study periods had larger increases in rat populations, the authors found. Of the 16 cities analyzed, 11 exhibited a growing rat population, including Washington, DC, San Francisco and New York. Population density was another contributing factor to the increase in rodents with denser cities seeing greater growth.
Hashtags
Try Our AI Features
Explore what Daily8 AI can do for you:
Comments
No comments yet...
Related Articles
Los Angeles Times
5 days ago
- Los Angeles Times
The start of California's fire season has moved up 6 weeks since 1990 thanks to climate change
You are not imagining it. Fire season in California is indeed starting earlier and lasting longer in virtually every region of California than it did two decades ago, researchers have found, thanks largely to human-caused climate change. In the Sierra Nevada, fire season starts about 24 days earlier than it did in the early 1990s. In the Northern Basin and Range region, which runs along the northernmost border with Nevada, it's 31 days earlier. And in the Cascade Range, which runs into Oregon, fire season now begins 46 days earlier than it once did, according to a study published this week in the journal Science Advances. 'Anecdotally, those of us living here have this sense that it's been happening sooner,' said Amanda Fencl, a Berkeley-based water specialist who directs climate science for the climate and energy program at the Union of Concerned Scientists and was not directly involved with the research. 'This is really an important study to quantify just how soon and where it is shifting, and to what extent.' Although the number of people living in California has grown by roughly 27% since the early 1990s, human-ignited fires have dropped significantly during that time, enabling the researchers to rule out human-caused blazes as the source of the additional burn days. Rather, the most significant factors shoving fire season forward are climate-related, they found: an earlier snowmelt and increased drying of soils and flammable vegetation as average temperatures rise. 'The main driver is the climate and meteorological conditions,' said Gavin D. Madakumbura, a UCLA postdoctoral researcher and the study's lead author. The effect is particularly pronounced in Northern California, where, in some regions, fire has become a near-constant threat. 'It's often said we no longer [have] a wildfire season, but that wildfire season is all year, and that's tied to warming temperatures,' said James Thorne, a UC Davis landscape ecologist who was not involved with the research. Definitively linking longer fire seasons to anthropogenic climate change, as this paper does, is 'a study I've been hoping someone would do for a long time,' he said. California is already on pace to see more fires and significantly more burned acreage than it did last year. More than 220,000 acres have burned in the state as of mid-July, almost 100,000 acres more than California has seen on average at this point in the year over the last five years, according to the California Department of Forestry and Fire Protection. That total does not include the 96,000 acres burned in the Gifford fire, which was 15% contained as of Thursday, nor three different fires that started Monday in Southern California that together have burned more than 2,800 acres and are not yet contained. It's also the worst year on record for fire-related economic damages. In 2018, the year the Camp fire destroyed the town of Paradise and killed more people than any wildfire in California history, wildfire damages statewide were an estimated $148.5 billion. The Palisades and Eaton fires in January may have caused up to $164 billion in damages, a UCLA study found. Times staff writer Grace Toohey contributed to this report.
Yahoo
6 days ago
- Yahoo
Earth's 'oldest' impact crater is much younger than previously thought, new study finds
When you buy through links on our articles, Future and its syndication partners may earn a commission. This article was originally published at The Conversation. The publication contributed the article to Expert Voices: Op-Ed & Insights. Ever been late because you misread a clock? Sometimes, the "clocks" geologists use to date events can also be misread. Unravelling Earth's 4.5-billion-year history with rocks is tricky business. Case in point: the discovery of an ancient meteorite impact crater was recently reported in the remote Pilbara region of Western Australia. The original study, by a different group, made headlines with the claim the crater formed 3.5 billion years ago. If true, it would be Earth's oldest by far. As it turns out, we'd also been investigating the same site. Our results are published in Science Advances today. While we agree that this is the site of an ancient meteorite impact, we have reached different conclusions about its age, size and significance. Let's consider the claims made about this fascinating crater. One impact crater, two versions of events Planetary scientists search for ancient impacts to learn about Earth's early formation. So far, nobody has found an impact crater older than the 2.23-billion-year-old Yarrabubba structure, also in Australia. (Some of the authors from both 2025 Pilbara studies were coauthors on the 2020 Yarrabubba study.) The new contender is located in an area called North Pole Dome. Despite the name, this isn't where Santa lives. It's an arid, hot, ochre-stained landscape. The first report on the new crater claimed it formed 3.5 billion years ago, and was more than 100 kilometers in diameter. It was proposed that such a large impact might have played a role in forming continental crust in the Pilbara. More speculatively, the researchers also suggested it may have influenced early life. Our study concludes the impact actually happened much later, sometime after 2.7 billion years ago. This is at least 800 million years younger than the earlier estimate (and we think it's probably even younger; more on that in a moment). We also determined the crater was much smaller – about 16km in diameter. In our view, this impact was too young and too small to have influenced continent formation or early life. So how could two studies arrive at such different findings? Subtle clues of an impact The originally circular crater is deeply eroded, leaving only subtle clues on the landscape. However, among the rust-colored basalts are unique telltale signs of meteorite impact: shatter cones. Shatter cones are distinctive fossilized imprints of shock waves that have passed through rocks. Their unique conical shapes form under brief but immense pressure where a meteorite strikes Earth. Both studies found shatter cones, and agree the site is an ancient impact. This new crater also needed a name. We consulted the local Aboriginal people, the Nyamal, who shared the traditional name for this place and its people: Miralga. The "Miralga impact structure" name recognizes this heritage. Determining the timing of the impact The impact age was estimated by field observations, as neither study found material likely to yield an impact age by radiometric dating – a method that uses measurements of radioactive isotopes. Both studies applied a geological principle called the law of superposition. This states that rock layers get deposited one on top of another over time, so rocks on top are younger than those below. The first group found shatter cones within and below a sedimentary layer known to have been deposited 3.47 billion years ago, but no shatter cones in younger rocks above this layer. This meant the impact occurred during deposition of the sedimentary layer. Their observation seemed to be a "smoking gun" for an impact 3.47 billion years ago. As it turns out, there was more to the story. Our investigation found shatter cones in the same 3.47 billion-year-old rocks, but also in younger overlying rocks, including lavas known to have erupted 2.77 billion years ago. The impact had to occur after the formation of the youngest rocks that contained shatter cones, meaning sometime after the 2.77-billion-year-old lavas. At the moment, we don't know precisely how young the crater is. We can only constrain the impact to have occurred between 2.7 billion and 400 million years ago. We're working on dating the impact by isotopic methods, but these results aren't yet in. Smaller than originally thought We made the first map showing where shatter cones are found. There are many hundreds over an area 6km across. From this map and their orientations, we calculate the original crater was about 16km in diameter. A 16km crater is a far cry from the original estimate of more than 100km. It's too small to have influenced the formation of continents or life. By the time of the impact, the Pilbara was already quite old. A new connection to Mars Science is a self-policing sport. Claims of discovery are based on data available at the time, but they often require modification based on new data or observations. While it's not the world's oldest, the Miralga impact is scientifically unique, as craters formed in basalt are rare. Most basalts there formed 3.47 billion years ago, making them the oldest shocked target rocks known. Prior to impact, these ancient basalts had been chemically altered by seawater. Sedimentary rocks nearby also contain the earliest well-established fossils on Earth. Such rocks likely covered much of early Earth and Mars. This makes the Miralga impact structure a playground for planetary scientists studying the cratered surface (and maybe early life) of Mars. It's an easily accessible proving ground for Mars exploration instruments and imagery, right here on Earth. This article is republished from The Conversation under a Creative Commons license. Read the original article. Solve the daily Crossword
New York Times
6 days ago
- New York Times
As Earth Warms, California Fire Season Is Starting Earlier, Study Finds
California's main wildfire season is starting earlier in the year, and human-caused climate change is a major reason, new research finds. The onset of summertime fire activity in large parts of the state has crept into spring by up to two months since the early 1990s, according to a study published Wednesday in the journal Science Advances. The change has been especially pronounced in the Cascade Range in Northern California, the coastal mountains of Central California and coastal Southern California from Monterey to San Diego. Officials and disaster managers in the state now often speak of fire as a year-round hazard, instead of a seasonal threat. The study rules out two factors that might theoretically be behind the shift: buildups of vegetation and changes in the number of fires ignited, either accidentally or on purpose, by humans. The more important drivers, the researchers found, are the effects of greenhouse warming, including earlier and faster snowmelt and a warmer atmosphere that pulls more moisture out of soil and vegetation. Want all of The Times? Subscribe.
