Want to plant trees to offset fossil fuels? You'd need all of North and Central America, study finds

Planting trees has plenty of benefits, but this popular carbon-removal method alone can't possibly counteract the planet-warming emissions caused by the world's largest fossil-fuel companies. To do that, trees would have to cover the entire land mass of North and Central America, according to a study out Thursday.
Many respected climate scientists and institutions say removing carbon emissions — not just reducing them — is essential to tackling climate change. And trees remove carbon simply by 'breathing.' But crunching the numbers, researchers found that the trees' collective ability to remove carbon through photosynthesis can't stand up to the potential emissions from the fossil fuel reserves of the 200 largest oil, gas and coal fuel companies — there's not enough available land on Earth to feasibly accomplish that.

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2 hours ago

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As the ocean warms, a new study found it's also changing color

For thousands of years, writers have come up with increasingly creative ways to describe the 'wine-dark sea.' But a new study suggests that modern poets may be faced with a slightly different palette. A study published Thursday in the journal Science found that the ocean is changing color as it warms. By analyzing satellite data from 2003 to 2022, researchers from Duke University and the Georgia Institute of Technology noticed that waters near the equator were getting bluer, while areas near the poles were turning greener. Lead author Haipeng Zhou calls it 'this greener greens or bluer blues phenomenon.' The culprit, the paper suggests, is the teeny tiny plant-like creatures that form the building blocks of the marine food web — phytoplankton. Phytoplankton are filled with a green pigment called chlorophyll that allows them to absorb energy from sunlight through photosynthesis. As waters near the equator warm, they're less hospitable to the microscopic critters, so the water appears bluer. At the poles, the colder water is far more nutrient-dense, so there's lots more phytoplankton to go around, giving the waters a rich, green tinge. It's not a new phenomenon. There's a reason the Caribbean is known as the land of dazzling turquoise waters, while Arctic waters are a dark teal contrast to the ivory ice floes around them. But Zhou, who began the research at Duke University and completed it as a postdoctoral researcher at Georgia Tech, found that as the ocean warms, this phenomenon is getting stronger. Their study only looked at the open ocean, not coastal waters. Near the coast, there are plenty of complicating factors that make it hard to clearly point to phytoplankton as the main cause of color changes, like dirt and sand floating in the water, shifting winds, pollution or even seagrass die off. To understand the concentrations of phytoplankton, the research team relied on a National Oceanic and Atmospheric Administration database made up of samples scooped from various research cruises all over the world. This database, plus satellite imagery, helped show the color shift in different regions of the ocean. The changing levels of phytoplankton could be bad news for fish in the tropics, or for communities that rely on those fish. But it could also be a boon for their northern and southern cousins. 'We all know that phytoplankton is the bottom of the food chain. Any impact on phytoplankton will have impacts on its predators,' Zhou said. Phytoplankton need sun and nutrients to flourish, but when the ocean warms, the individual layers that make up the sea grow more stratified, so it's harder for phytoplankton to float up and down the water column to access the same light and nutrients they're used to, he said. So while scientists can clearly say that warmer waters lead to fewer phytoplankton, and they know that climate change is one of the main reasons the oceans are heating up, it's not clear if climate change is the reason for the color shift. 'We need longer records, 30 years, 40 years, to make us more confident whether it is linked to climate change or global variability,' Zhou said. The study only looked at about 20 years of data, which Zhou said is enough to confidently say that something has changed, but not long enough to know what caused that change. Other factors can and do affect water temperature, like the shift in trade winds over the Atlantic that led to a coral-killing marine heat wave in 2023. 'The study period was too short to rule out the influence of recurring climate phenomena such as El Niño,' wrote co-author Susan Lozier, Dean of the College of Sciences at Georgia Tech, in a statement. However, Zhou added, more research may very well find that this color-shifting trend continues into the future as human-caused climate change continues to heat up the oceans. 'The temperature of the water is rising. While there's no evidence showing that this progress will slow down, it's very likely we'll have warmer waters in the future, which means we'll have a continuous impact on the ocean ecosystem.' Correction: An initial version of this story incorrectly listed the start of the period analyzed on satellite as 2009. It was 2003.

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2 hours ago

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A 'new star' has exploded into the night sky — and you can see it from North America

When you buy through links on our articles, Future and its syndication partners may earn a commission. A "new star" is shining in the constellation Lupus thanks to an unexpected stellar explosion within the Milky Way — and it can currently be seen with the naked eye from parts of North America. On June 12, astronomers from the All-Sky Automated Survey for Supernovae at Ohio State University first spotted the new point of light, which had an apparent magnitude of +8.7 at the time, still too dim to be seen by the naked eye, Sky & Telescope originally reported. (A smaller magnitude signifies a brighter object; for example, the moon has an apparent magnitude of -12.7). Over the next few days, the rapidly brightening object took on several temporary names — including AT 2025nlr, ASASSN-25cm, and N Lup 2025 — as researchers scrambled to determine its identity. Astronomer Yusuke Tampo, from the South African Astronomical Observatory at the University of Cape Town, then analyzed the light coming from the object and determined that it is likely a classical nova — a massive stellar explosion that temporarily shines bright in the night sky. On June 16, it was given the official designation V462 Lupi. By June 18, V462 Lupi had brightened to an apparent magnitude of +5.7, which makes it just visible to the naked eye. This also makes it around 4 million times brighter than its extremely dim progenitor star was before June 12, according to Related: Nearly 900 years ago, astronomers spotted a strange, bright light in the sky. We finally know what caused it. There is a chance that the nova will continue to brighten in the coming days, making it even easier to spot. The Lupus constellation is located in the southern sky, meaning that V462 Lupi is most easily visible from the Southern Hemisphere. However, it can also be seen from North America, close to the southern horizon, just after sunset. Amateur astronomers from the U.S. have reported seeing it in places such as Arizona and California, and as far north as Lake Superior, according to Sky & Telescope. You may be able to spot it without any additional equipment. However, it would be easier to spot if you had a decent telescope or a pair of stargazing binoculars, especially if you are viewing it from the U.S. or if the explosion starts to dim over the coming days. Unlike supernovas, which are so powerful that they completely rip stars apart, a nova only affects the outer layer of a star. Classical novas, such as V462 Lupi, occur in a specific type of binary system, where a more massive white dwarf star is pulling material away from its larger partner. When enough material has been accreted onto the dwarf star's surface, the pressure builds up and triggers an explosion that burns up most of the stolen gas and shoots pulses of bright light toward Earth. Naked-eye classical novas are rare. They appear "no more than once a year," representatives wrote, "and most are so close to the limit of naked-eye sensitivity that they can be invisible despite being technically [visible]." RELATED STORIES —Supernova that lit up Earth's skies 843 years ago has a flowering 'zombie star' at its heart — and it's still exploding —Mystery explosion 1,000 years ago may be a rare, third type of supernova —Rare quadruple supernova on our 'cosmic doorstep' will shine brighter than the moon when it blows up in 23 billion years Some novas are also recurring events, blowing their top at regular intervals: For example, the long-awaited T Coronae Borealis nova, also known as the "Blaze Star," lights up our skies roughly every 80 years. However, astronomers have been predicting that the Blaze Star will reappear imminently for the last 15 months, and it is yet to emerge, which shows that it is not an exact science. As this is the first recorded appearance of V462 Lupi, we have no idea if or when it will explode again in the future.

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4 hours ago

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The ocean is changing colors, researchers say. Here's what it means.

Warming waters are causing the colors of the ocean to change -- a trend that could impact humans if it were to continue, according to new research. Satellite data shows that ocean waters are getting greener at the poles and bluer toward the equator, according to a paper published Thursday in the journal Science. MORE: How penguin poop can help to mitigate climate change The change in hue is being caused by shifting concentrations of a green pigment called chlorophyll, which is produced by phytoplankton, Haipeng Zhao, a postdoctoral researcher and lead author of the paper, told ABC News. Phytoplankton are photosynthetic marine organisms. As algae, phytoplankton has photosynthetic pigments, which absorb green light and cause the waters around it to appear primarily green, Susan Lozier, dean of the College of Sciences at the Georgia Institute of Technology and co-author of the paper, told ABC News. Where phytoplankton are absent, the water appears blue. The researchers analyzed satellite data on the open ocean collected from 2003 to 2022 by a NASA instrument that combs through the planet every two days to measure light wavelength, according to the paper. The presence of chlorophyll in open ocean is a proxy for concentrations of phytoplankton biomass. The colors indicate how chlorophyll concentration is changing at specific latitudes, in which the subtropics are generally losing chlorophyll, and the polar regions -- the high-latitude regions -- are greening, the researchers said. MORE: Global sea level rose faster than expected in 2024, according to NASA analysis Green areas became greener, especially in the northern hemisphere, and blue regions "got even bluer," according to a press release by Duke University. "We borrowed concepts from economics called the Lorenz curve and the Gini index, which together show how wealth is distributed in a society," said Nicolas Cassar, the Lee Hill Snowdon Bass chair at Duke University's Nicholas School of the Environment, in a statement. "So, we thought, let's apply these to see whether the proportion of the ocean that holds the most chlorophyll has changed over time." The researchers examined how the patterns they observed were affected by variables like sea surface temperature, wind speed, light availability and mixed layer depth. Warming seas correlated with changes in chlorophyll concentration, they found. The other variables did not show any significant associations to chlorophyll concentration. However, the findings cannot be solely attributed to climate change, the authors said. The study period was too short to rule out the influence of recurring climate phenomena, Lozier said. "We haven't been able to observe the ocean for decades and decades, just because the satellite technology is pretty new," Lozier said. MORE: How marine biologists are using elephant seals as nature's 'artificial intelligence' After focusing his Ph.D. on regional studies in high-latitude oceans, Zhao said he was inspired to dive deeper to see whether oceans were transforming in color throughout the rest of the world. "The ocean has been warming, so there's a big question then about, what are the biological consequences of the ocean warming?" Lozier said. Several studies since the 1990s have documented enhanced greening on land, attributed to average leaf color increasing due to rising temperatures and other factors, according to the researchers. However, documenting such changes in the ocean has proven to be more difficult. The satellite images provide data on the chlorophyll production at the surface, but the picture is still incomplete, the researchers said. MORE: How to turn ocean waves into renewable energy If the trend continues, marine food webs could be impacted, the researchers said. Since phytoplankton are at the base of the food chain, it can be used to determine the presence of fish, too, Lozier said. A persistent decline in phytoplankton near the equator could cause a redistribution of the location of fisheries, the authors said. This could be especially impactful in low to middle-income nations, such as the Pacific Islands, that rely on commercial fishing for food and economic development, the authors said.