A few milligrams of all the scientific news of the week
Posted at 8:00 a.m.
Record heat for the oceans in 2021
If there is one part of our planet that is particularly affected by global warming, it is the oceans, which capture 90% of the temperature increases caused by human activities. However, according to a study published in the journal Advances in Atmospheric Sciences, the year 2021 set a new sea heat record. At a depth of 2000 m, the oceans absorbed 227 zettajoules more energy last year than the average for the years 1981-2010. Note in particular that the rise in ocean temperature is the cause of several extreme weather phenomena that have become more frequent in recent years.
Quiz
How often to feed your dog so that he ages in better health?
PHOTO OLENA YAKOBCHUK, GETTY IMAGES
Dogs that eat only one meal a day age healthier, according to researchers at the University of Washington.
Responnse
It seems that doggies who eat once a day are more likely to age without developing diseases, such as cancer. At least that’s the conclusion of a team from the University of Washington, who analyzed data from thousands of dog owners in the United States. The study was published on the bioRxiv dissemination platform. Further studies will be needed to confirm this hypothesis. Until then, don’t forget to feed man’s best friend!
The number
98.3 billion
PHOTO ALEX GALLARDO, REUTERS ARCHIVES
Eating significantly less meat could reduce greenhouse gas emissions from agricultural production by two-thirds, according to a Dutch study.
Researchers at the University of Leiden in the Netherlands recently calculated the amount of greenhouse gases that could be eliminated by adopting a diet that significantly limits meat consumption. According to their estimates based on the dietary habits of people in the 50 richest countries, such a change would cut emissions from agricultural production globally by two-thirds, or 98.3 billion tonnes of carbon dioxide. . The study was published in the journal nature food.
Trees store less carbon when it’s very hot
PHOTO EZEQUIEL BECERRA, AGENCE FRANCE-PRESSE ARCHIVES
Trees in tropical forests store less carbon in warmer years, US researchers have found.
It is well known that trees can store large amounts of carbon. At the same time, the canopy is one of the most obvious natural solutions to combat global warming. However, American researchers have recently discovered that in the tropical forest, trees store less carbon during warmer years. Between 1997 and 2018, biologists Deborah and David Clark took different measurements in the forest located in the La Selva Reserve, Costa Rica. They found a decline in tree growth in years when the temperature regularly exceeded 28℃. These, remember, use the carbon in the air to ensure their growth. The study was published in the journal JGR Biogeosciences.
And soils release more carbon in hot weather
PHOTO SHAUN BEST, REUTERS ARCHIVES
Soils release more carbon into the atmosphere when temperatures rise, according to a British study.
A study by scientists at the University of Exeter in the UK has shown that increases in temperature cause soils to release more carbon into the atmosphere. In the study published in NatureCommunications, the Exeter team analyzed 9,000 soil samples and found that coarse-grained soils release up to three times more carbon than fine-grained soils when the temperature warms. This finding is all the more worrying since coarse-grained soils are found in temperate and polar climates, where global warming is much faster. Small-grained soils are generally found in tropical regions.