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09.01.2023
THEME: ENVIRONMENT

More than half of glaciers will be gone by 2100 if global warming continues at the current rate

The Climate Change Conference of the Parties (COP) is where the United Nations come together to act towards achieving the world's collective climate goals agreed upon in the Paris Agreement. The Paris Agreement is a legally binding international treaty on climate change. It was adopted by 196 Parties at COP 21 in Paris on December 12 2015. Its goal is to limit global warming to below 2C (Celsius degrees), preferably to 1.5C, compared to pre-industrial levels. Earlier this year, at COP 27 in Sharm el-Sheikh, leaders recognized that more effort would be needed to achieve the objective of 1.5C. Unfortunately, scientists are finding out that even this best-case scenario may not be enough to avoid dramatic and profound changes in the Earth's climate.

A recent study published in Science shows that 49% of glaciers would disappear under the most optimistic scenario of 1.5C warming within 2100 AD. However, if global heating continues under the current scenario (reaching 2.7C of warming), losses would be more significant, with 68% of glaciers disappearing. If this happened, almost no glaciers would be left in central Europe, western Canada and the US by the end of the next century. The research team of scientists led by Dr Robert W. McNabb (UK) used two decades of satellite data to map the planet's glaciers with greater precision than ever before. Previous models relied on measurements of specific glaciers. Scientists would then extrapolate that information, but now they can get precise data points on each of the planet's 200,000 glaciers. These data gave insight into how many would be lost under different climate change scenarios. In particular, it was possible to observe mountain glaciers. Mountain glacier melt is believed to contribute to more than a third of sea level rise. A lot of this loss is unavoidable, but the magnitude of loss is directly related to temperature increases, so acting on the climate crisis is vital to contain this phenomenon. The result of the study indicates that mountain glacier melt would significantly raise the sea level. Moreover, it threatens the water supply to 2 billion people and increases the risk of natural hazards such as flooding.

After the alarming temperatures registered at the beginning of the year in central Europe, and the recent and worrisome observations from the Alps' glaciers, science is now getting more accurate in indicating the extent of the effects of global warming. While rising sea levels were initially the primary concern, water droughts may be a more imminent issue involving largely populated areas. According to the latest observations, this a problem that may become critical in just a few decades.

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08.01.2023
THEME: TECHNOLOGY

A new study demonstrated that ancient Roman concrete is more advanced than what we use today

The ancient Romans were masters of engineering, constructing vast networks of roads, aqueducts, ports, and massive buildings, whose remains have survived for two millennia. They built many of these structures with concrete. For instance, the Pantheon - AD 128 - is still intact, and some ancient aqueducts still deliver water to Rome today. In contrast, many modern concrete structures have crumbled after a few decades.

The reason for such extraordinary resilience was still unknown until a recent study published in Science, the fruit of collaboration between the University of Udine (IT) and the Massachusetts Institute of Technology (US). In their research, the authors analyzed the chemical composition of 2000-year-old concrete samples obtained from the archaeological site of Privernum, Italy. The observations are based on cutting-edge electron microscopy and x-ray technologies. They discovered that ancient concrete-manufacturing strategies had incorporated several key self-healing functionalities. The unknown self-healing capabilities of ancient concrete are due to the so-called "lime clasts" - white microscopic minerals that are a typical mark of Roman concrete. The lime clasts develop a brittle architecture thanks to a specific hot-mixing manufacturing protocol, creating an easily fractured and reactive calcium source. As tiny cracks start forming within the concrete, they can preferentially travel through the high-surface-area lime clasts. This material can then react with water (like the one that would penetrate a cracked surface on a rainy day), creating a calcium-saturated solution that recrystallizes and fills the crack.

It is worth noting that concrete is the most ubiquitous construction material in the world, but its production has serious environmental consequences. One method to reduce the carbon footprint - which accounts for up to 8% of total global greenhouse gas emissions - is to improve the longevity of concrete. The resulting extended use life, combined with a reduced need for repair, could reduce the environmental impact and improve the economic life cycle of modern constructs. Such a relevant innovation may now be at hand - not thanks to modern science, but to our ancestors' inheritance.

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