Red skies in August, longer fire seasons and checking air quality before taking my toddler to the park. This has become the new norm in the western United States as wildfires become more frequent, larger and more catastrophic.

As an ecologist at the University of Colorado Boulder, I know that fires are part of the natural processes that forests need to stay healthy. But the combined effects of a warmer and drier climate, more people living in fire-prone areas and vegetation and debris built up over years of fire suppression are leading to more severe fires that spread faster. And that’s putting humans, ecosystems and economies at risk.

To help prevent catastrophic fires, the U.S. Forest Service issued a 10-year strategy in 2022 that includes scaling up the use of controlled burns and other techniques to remove excess plant growth and dry, dead materials that fuel wildfires.

However, the Forest Service’s wildfire management activities have been thrown into turmoil in 2025 with funding cuts and disruptions and uncertainty from the federal government.

The planet just saw its hottest year on record. If spring and summer 2025 are also dry and hot, conditions could be prime for severe fires again.

More severe fires harm forest recovery and people

Today’s severe wildfires have been pushing societies, emergency response systems and forests beyond what they have evolved to handle.

Extreme fires have burned into cities, including destroying thousands of homes in the Los Angeles area in 2025 and near Boulder, Colorado, in 2021. They threaten downstream public drinking water by increasing sediments and contaminants in water supplies, as well as infrastructure, air quality and rural economies. They also increase the risk of flooding and mudslides from soil erosion. And they undermine efforts to mitigate climate change by releasing carbon stored in these ecosystems.

In some cases, fires burned so hot and deep into the soil that the forests are not growing back.

While many species are adapted to survive low-level fires, severe blazes can damage the seeds and cones needed for forests to regrow. My team has seen this trend outside of Fort Collins, Colorado, where four years after the Cameron Peak fire, forests have still not come back the way ecologists would expect them to under past, less severe fires. Returning to a strategy of fire suppression − or trying to “go toe-to-toe with every fire” − will make these cases more common.

Proactive wildfire management can help reduce the risk to forests and property.

Measures such as prescribed burns have proven to be effective for maintaining healthy forests and reducing the severity of subsequent wildfires. A recent review found that selective thinning followed by prescribed fire reduced subsequent fire severity by 72% on average, and prescribed fire on its own reduced severity by 62%.

But managing forests well requires knowing how forests are changing, where trees are dying and where undergrowth has built up and increased fire hazards. And, for federal lands, these are some of the jobs that are being targeted by the Trump administration.

Some of the Forest Service staff who were fired or put in limbo by the Trump administration are those who do research or collect and communicate critical data about forests and fire risk. Other fired staff provided support so crews could clear flammable debris and carry out fuel treatments such as prescribed burns, thinning forests and building fire breaks.

Losing people in these roles is like firing all primary care doctors and leaving only EMTs. Both are clearly needed. As many people know from emergency room bills, preventing emergencies is less costly than dealing with the damage later.

Logging is not a long-term fire solution

The Trump administration cited “wildfire risk reduction” when it issued an emergency order to increase logging in national forests by 25%.

But private − unregulated − forest management looks a lot different than managing forests to prevent destructive fires.

Logging, depending on the practice, can involve clear-cutting trees and other techniques that compromise soils. Exposing a forest’s soils and dead vegetation to more sunlight also dries them out, which can increase fire risk in the near term.

In general, logging that focuses on extracting the highest-value trees leaves thinner trees that are more vulnerable to fires. A study in the Pacific Northwest found that replanting logged land with the same age and size of trees can lead to more severe fires in the future.

Research and data are essential

For many people in the western U.S., these risks hit close to home.

I’ve seen neighborhoods burn and friends and family displaced, and I have contended with regular air quality warnings and red flag days signaling a high fire risk. I’ve also seen beloved landscapes, such as those on Cameron Peak, transform when conifers that once made up the forest have not regrown.

My scientific research group and collaborations with other scientists have been helping to identify cost-effective solutions. That includes which fuel-treatment methods are most effective, which types of forests and conditions they work best in and how often they are needed. We’re also planning research projects to better understand which forests are at greatest risk of not recovering after fires.

This sort of research is what robust, cost-effective land management is based on.

When careful, evidence-based forest management is replaced with a heavy emphasis on suppressing every fire or clear-cutting forests, I worry that human lives, property and economies, as well as the natural legacy of public lands left to every American, are at risk.

Laura Dee, Associate Professor of Ecology, University of Colorado Boulder

This article is republished from The Conversation under a Creative Commons license. Read the original article.

The detection of life beyond Earth would be one of the most profound discoveries in the history of science. The Milky Way galaxy alone hosts hundreds of millions of potentially habitable planets. Astronomers are using powerful space telescopes to look for molecular indicators of biology in the atmospheres of the most Earth-like of these planets.

But so far, no solid evidence of life has ever been found beyond the Earth. A paper published in April 2025 claimed to detect a signature of life in the atmosphere of the planet K2-18b. And while this discovery is intriguing, most astronomers – including the paper’s authors – aren’t ready to claim that it means extraterrestrial life exists. A detection of life would be a remarkable development.

The astronomer Carl Sagan used the phrase, “Extraordinary claims require extraordinary evidence,” in regard to searching for alien life. It conveys the idea that there should be a high bar for evidence to support a remarkable claim.

I’m an astronomer who has written a book about astrobiology. Over my career, I’ve seen some compelling scientific discoveries. But to reach this threshold of finding life beyond Earth, a result needs to fit several important criteria.

When is a result important and reliable?

There are three criteria for a scientific result to represent a true discovery and not be subject to uncertainty and doubt. How does the claim of life on K2-18b measure up?

First, the experiment needs to measure a meaningful and important quantity. Researchers observed K2-18b’s atmosphere with the James Webb Space Telescope and saw a spectral feature that they identified as dimethyl sulfide.

On Earth, dimethyl sulfide is associated with biology, in particular bacteria and plankton in the oceans. However, it can also arise by other means, so this single molecule is not conclusive proof of life.

Second, the detection needs to be strong. Every detector has some noise from the random motion of electrons. The signal should be strong enough to have a low probability of arising by chance from this noise.

The K2-18b detection has a significance of 3-sigma, which means it has a 0.3% probability of arising by chance.

That sounds low, but most scientists would consider that a weak detection. There are many molecules that could create a feature in the same spectral range.

The “gold standard” for scientific detection is 5-sigma, which means the probability of the finding happening by chance is less than 0.00006%. For example, physicists at CERN gathered data patiently for two years until they had a 5-sigma detection of the Higgs boson particle, leading to a Nobel Prize one year later in 2013.

Third, a result needs to be repeatable. Results are considered reliable when they’ve been repeated – ideally corroborated by other investigators or confirmed using a different instrument. For K2-18b, this might mean detecting other molecules that indicate biology, such as oxygen in the planet’s atmosphere. Without more and better data, most researchers are viewing the claim of life on K2-18b with skepticism.

Claims of life on Mars

In the past, some scientists have claimed to have found life much closer to home, on the planet Mars.

Over a century ago, retired Boston merchant turned astronomer Percival Lowell claimed that linear features he saw on the surface of Mars were canals, constructed by a dying civilization to transport water from the poles to the equator. Artificial waterways on Mars would certainly have been a major discovery, but this example failed the other two criteria: strong evidence and repeatability.

Lowell was misled by his visual observations, and he was engaging in wishful thinking. No other astronomers could confirm his findings.

In 1996, NASA held a press conference where a team of scientists presented evidence for biology in the Martian meteorite ALH 84001. Their evidence included an evocative image that seemed to show microfossils in the meteorite.

However, scientists have come up with explanations for the meteorite’s unusual features that do not involve biology. That extraordinary claim has dissipated.

More recently, astronomers detected low levels of methane in the atmosphere of Mars. Like dimethyl sulfide and oxygen, methane on Earth is made primarily – but not exclusively – by life. Different spacecraft and rovers on the Martian surface have returned conflicting results, where a detection with one spacecraft was not confirmed by another.

The low level and variability of methane on Mars is still a mystery. And in the absence of definitive evidence that this very low level of methane has a biological origin, nobody is claiming definitive evidence of life on Mars.

Claims of advanced civilizations

Detecting microbial life on Mars or an exoplanet would be dramatic, but the discovery of extraterrestrial civilizations would be truly spectacular.

The search for extraterrestrial intelligence, or SETI, has been underway for 75 years. No messages have ever been received, but in 1977 a radio telescope in Ohio detected a strong signal that lasted only for a minute.

This signal was so unusual that an astronomer working at the telescope wrote “Wow!” on the printout, giving the signal its name. Unfortunately, nothing like it has since been detected from that region of the sky, so the Wow! Signal fails the test of repeatability.

In 2017, a rocky, cigar-shaped object called ‘Oumuamua was the first known interstellar object to visit the solar system. ‘Oumuamua’s strange shape and trajectory led Harvard astronomer Avi Loeb to argue that it was an alien artifact. However, the object has already left the solar system, so there’s no chance for astronomers to observe it again. And some researchers have gathered evidence suggesting that it’s just a comet.

While many scientists think we aren’t alone, given the enormous amount of habitable real estate beyond Earth, no detection has cleared the threshold enunciated by Carl Sagan.

Claims about the universe

These same criteria apply to research about the entire universe. One particular concern in cosmology is the fact that, unlike the case of planets, there is only one universe to study.

A cautionary tale comes from attempts to show that the universe went through a period of extremely rapid expansion a fraction of a second after the Big Bang. Cosmologists call this event inflation, and it is invoked to explain why the universe is now smooth and flat.

In 2014, astronomers claimed to have found evidence for inflation in a subtle signal from microwaves left over after the Big Bang. Within a year, however, the team retracted the result because the signal had a mundane explanation: They had confused dust in our galaxy with a signature of inflation.

On the other hand, the discovery of the universe’s acceleration shows the success of the scientific method. In 1929, astronomer Edwin Hubble found that the universe was expanding. Then, in 1998, evidence emerged that this cosmic expansion is accelerating. Physicists were startled by this result.

Two research groups used supernovae to separately trace the expansion. In a friendly rivalry, they used different sets of supernovae but got the same result. Independent corroboration increased their confidence that the universe was accelerating. They called the force behind this accelerating expansion dark energy and received a Nobel Prize in 2011 for its discovery.

On scales large and small, astronomers try to set a high bar of evidence before claiming a discovery.

Chris Impey, University Distinguished Professor of Astronomy, University of Arizona

This article is republished from The Conversation under a Creative Commons license. Read the original article.