Latest news with #EarthScientists
Yahoo
2 days ago
- Science
- Yahoo
First Signal of Climate Change Became Detectable 130 Years Ago
If scientists of the 19th century could have used modern tools to study the atmosphere, they might have noticed the early warning signs of a major shift: human activities, like burning coal and wood, had already begun changing the climate. In a recent thought experiment, a team of Earth and atmospheric scientists found that with the right equipment, we could have hypothetically detected the first stages of this shift by around 1885, just before fossil fuel-powered cars were invented. Their results suggest that a discernible human influence on atmospheric temperature has likely existed for over 130 years. In reality, the heat-trapping properties of carbon dioxide were only just being discovered in the mid-1800s. Emissions of this gas were rising as a result of the Industrial Revolution in Europe, and it wasn't until the 1970s that systematic scientific studies really began to reveal its role – and our hand – in modern climate change. In their hypothetical scenario, the researchers set the assumption that scientists were capable of making accurate measurements of global atmospheric changes by 1860, equipping them with instruments as reliable as today's satellite microwave radiometers and contemporary estimates of carbon dioxide changes from ice cores and stratospheric balloons. "We then apply a pattern-based 'fingerprint' method to disentangle human and natural effects on climate," the authors explain. Despite the overall warming effect of greenhouse gases, climate change's early warning signal would have actually taken the form of stratospheric cooling. This is a direct radiative response to human emissions of carbon dioxide and other greenhouse gases, and human-driven ozone loss. Greenhouse gases trap radiation from the Earth's surface in the lower layer of the atmosphere, the troposphere. These gases increase the reflective power of the next layer, the stratosphere, causing heat to bounce off it and back toward Earth. Meanwhile, ozone depletion decreases the stratosphere's ability to absorb radiative heat. The overall effect is stratospheric cooling, while below, the troposphere starts to warm. The stratosphere is also less affected by the fluctuating weather going on in the troposphere below, which is what makes it difficult to see long-term climate patterns from ground measurements. "Pronounced cooling of the mid- to upper stratosphere, mainly driven by anthropogenic increases in carbon dioxide, would have been identifiable with high confidence by approximately 1885, before the advent of gas-powered cars," the authors write. "Even if our monitoring capability in 1860 had not been global, and high-quality stratospheric temperature measurements existed for Northern Hemisphere mid-latitudes only, it still would have been feasible to detect human-caused stratospheric cooling by 1894, only 34 years after the assumed start of climate monitoring." Unless someone invents a time machine, we'll never know if this foresight would have prevented the devastating effects of unchecked fossil fuel emissions through the 20th and 21st centuries, which we are only just beginning to feel. We've known about climate change for at least 50 years now, and we are still yet to find a way to quit our species' fossil fuel habit. "We know with high confidence that sustainable pathways must be followed to avoid dangerous anthropogenic interference with climate. For the mid- to upper stratosphere and the troposphere, the projected future changes over the next 26 years are larger than the simulated changes over the 39-year period from 1986 to 2024," the authors conclude. "Humanity is now at the threshold of dangerous anthropogenic interference. Our near-term choices will determine whether or not we cross that threshold." The research was published in PNAS. Extremely Dangerous Heat Wave Now Affecting Half of US Population Glass Bottles Actually Contain More Microplastics, Scientists Find Engineered E. Coli Transforms Waste Plastic Into Common Painkiller
The Sun
7 days ago
- Science
- The Sun
Mysterious deep Earth ‘heartbeat' pulsing beneath Africa will form NEW ocean as it splits continent in two
A NEW ocean is forming beneath Ethiopia as a "heartbeat"-like pulse deep below the Earth's surface splits the African continent in two, according to scientists. While a new ocean will eventually give six countries a new coastline, neither you nor I will ever be able to swim in its waters. 5 5 An international research team, led by Earth scientists at the University of Southampton, have discovered rhythmic surges of molten mantle rock rising from deep within the Earth. It is bubbling up beneath Africa - and its pulses are gradually tearing the continent apart, starting in the Afar region of Ethiopia. The Afar region is a rare place on Earth where three tectonic rifts converge: the Main Ethiopian Rift, the Red Sea Rift, and the Gulf of Aden Rift. Scientists previously thought Africa's tectonic plates, which collided to form large mountains and pulled apart to create vast basins millions of years ago, were simply moving apart again. However, a study in May suggested that intense volcanic activity deep underground may be fuelling the divide. Little was known about the hot upwelling of mantle and how it behaves beneath rifting tectonic plates - until now. The latest research, published in Nature Geoscience today, revealed that the giant fiery plume pulses like a "heartbeat" and is repeatedly pushing against the tectonic plate above it. When the tectonic plate eventually ruptures from the pressure, the continent will divide and a new ocean will flood in. "We found that the mantle beneath Afar is not uniform or stationary – it pulses, and these pulses carry distinct chemical signatures," lead author Dr Emma Watts, who conducted the research at the University of Southampton, said in a statement. Watts, who is now based at Swansea University, added: "These ascending pulses of partially molten mantle are channelled by the rifting plates above. Shocking moment 1,000ft fiery lava jet erupts in 6-hour volcano frenzy as scientists warn of wind spreading toxic gas "That's important for how we think about the interaction between Earth's interior and its surface." The team collected over 130 volcanic rock samples from across the Afar region and the Main Ethiopian Rift to piece together the structure of the deep Earth that is splitting. These pulses appear to behave differently depending on the thickness of the plate, and how fast it's pulling apart. Professor Tom Gernon, a co-author of the study Researchers found that the pattern of the rhythmic pulse is dictated by the tectonic plate it bubbles beneath - such as how the plate moves, or how thick it is. Professor Tom Gernon, a co-author of the study, said: "The chemical striping suggests the plume is pulsing, like a heartbeat. "These pulses appear to behave differently depending on the thickness of the plate, and how fast it's pulling apart. "In faster-spreading rifts like the Red Sea, the pulses travel more efficiently and regularly like a pulse through a narrow artery." 5 Associate professor Dr Derek Keir, another co-author of the study, said the findings had "profound implications" for how scientists understand volcanoes, earthquake activity, and the process of continental breakup. 'The work shows that deep mantle upwellings can flow beneath the base of tectonic plates and help to focus volcanic activity to where the tectonic plate is thinnest," he added. The East African Rift System (EARS) is the largest active continental rift system on Earth. It is in the process of ripping through around 2,175miles (3,500km) of Africa. In January, Ken Macdonald, a professor at the University of California, warned the continent was splitting at a faster rate than expected. Somalia and parts of Ethiopia, Kenya, and Tanzania will form a distinct continent, accompanied by a fresh coastline. The new ocean could become as deep as the Atlantic if waters continue to flow into the area, Macdonald added. While cracks are already appearing along the rift, it is not expected to fully rupture for another several million years. 5 5
