What if the climate situation is more dramatic than we thought? What if the +1.5°C mark was already crossed a decade ago and temperatures began to rise much earlier than we thought? Here are the results of a new study that confirms, although controversial, that it is time to act.
This will interest you too
[EN VIDÉO] Interview with Jan Guzel: Is global warming of human origin? French paleoclimatologist Jean Guzel enlightens us about the human share of responsibility in…
Here is a new study that has caused a stir within the community Climate scientistsClimate scientists. Published in review The nature of climate changeOne article suggests that we are already +1.5°C above the pre-industrial era. And for good reason: the climate of the pre-industrial era was much colder, and human-related global warming would have started much earlier than we thought!
Did you know ? The phenomenon of global warming was first proven by a woman in… 1856! Discover his story in Science Hunters. © Futura
Needless to say, this hypothesis is not unanimous. However, it is necessary to consider this, because it may have strong effects. Most importantly, we will actually have less time than expected to try to turn things around.
Sponges: vast climate archives
By studying marine sponges from the Caribbean, a team of researchers came to this conclusion. Sponges are actually sensitive to many environmental factors, such as water temperature, acidity, or even carbon dioxide level.2 Atmosphere, the differences of which affect its growth. These marine creatures have lived for a very long time, several hundred years, making them a veritable climate archive to study Revolutionary periodRevolutionary period industrial.
Thus, the analysis of sponges made it possible to reconstruct the evolution of climate in the nineteenth century. It turns out that the results were completely different from what is currently accepted by the scientific community. The study reveals that temperatures were approximately in the middle of the nineteenth centuryH The century would have been 1°C cooler than previously thought and the onset of global warming would have been linked to this BroadcastBroadcast Greenhouse gases likely started about 80 years earlier than current models suggest! This makes a big difference.
Temperatures rising since 1860, surpassing the +1.5°C mark 10 years ago?
Models accepted by the Intergovernmental Panel on Climate Change (IPCC)Intergovernmental Panel on Climate Changethe Intergovernmental Panel on Climate ChangeIntergovernmental Panel on Climate Change) They do suggest that human activity began to influence Earth's climate after 1900. They base this on measurements of ocean temperatures obtained by boat at the end of the 19th century.H a century. Values that, according to the study authors, could be biased by the methodology used at the time and would therefore be much less accurate than the data set obtained through the sponge study. To support their observations of an early onset of global warming, the researchers also point out that greenhouse gas emissions began well before 1900, since the Industrial Revolution of the early 19th century.
In detail, scientists studied the fine sediments of CalciumCalcium And based on StrontiumStrontium Marking the skeleton of a sponge, based on the principle that heating water leads to greater deposition of strontium compared to calcium, and vice versa for cooling. Their results show that global warming began as early as 1860. Combined with the fact that temperatures at the beginning of the 19th century were lower than previously thought, the researchers conclude that we have in fact been beyond +1.5°C for a decade. , and that we are currently at an increase of +1.7°C compared to the pre-industrial era. We will therefore be late in our efforts to limit global warming, which may therefore accelerate more than we expect in the future.
A study that raises controversy
However, as mentioned above, these results are far from unanimous. The first argument to be made against this study is the fact that it does not rely on data obtained and evenly distributed around the world, unlike temperature recordings made by boats. In fact, the sponges only come from a very specific region and it remains possible that the inferred temperature values actually only represent periodic changes associated with El Niño and La Niña. In short, the debate remains open.
It therefore seems wise to remain cautious about the results presented by this new study. But all scholars agree on one point: Whatever happens, action is urgently needed.
