American scientists have summarized data on the ratio of isotopes of various elements in marine sediments over the past 24 thousand years. As a result, they concluded that modern climate warming had become its fastest change in several tens of thousands of years, Naked science states, citing Nature.
But the new work ignores several others that have shown that the rate of temperature change after the cometary bombardment was higher than it is now.
The isotope ratios made it possible to determine the rate and range of temperature changes over the specified period. It turned out that the ice age was even colder than previously thought. The average temperature on the planet was then about seven degrees Celsius.
Scientists note that by the 18th century, the planet was 7.0 ± 1.0° C warmer than 24 thousand years ago, at the peak of the last glaciation. This estimate differs from earlier estimates that the Ice Age was only 6° C colder than the pre-industrial era.
The difference may seem small, but it is significant. Seven degrees Celsius is close to the state of “Snowball Earth,” complete glaciation in all zones, including tropical.
Another conclusion of the work is that from 9.5 thousand years ago until the 18th century, there was slow but noticeable warming – by 0.5° C. Until now, it was believed that four to nine thousand years ago, there was a Holocene climatic optimum on the planet with temperatures one degree higher than the present. It was this that explained the fact that the taiga at that time reached the Arctic Ocean, and the tundra did not exist. They also explained that there were vast savannas on the Sahara desert, which have now turned into sands.
If the data from the new work is correct, then the warmer north of Eurasia and the humid Sahara are explained by other reasons that are still unknown. The authors offer nothing to explain this.
In addition, scientists argue that the increase in global temperatures by one degree over the past 100 years is the fastest climate change in the last 24 thousand years. Before that, scientists believed that temperatures changed faster than now after the fall of the comet on the planet 12,800 years ago.
For example, this follows from the fact that literally in a matter of tens of years, the vegetation of Western Europe, which until then resembled a modern one, suddenly changed to tundra. If the new work is correct, it turns out that the temperature changes in the world as a whole during this period were negligible. The researchers do not explain how this fits in with the avalanche-like drop in temperatures in Europe and North America.
Scientists from Germany and the United States said that the effects of global warming are being felt worldwide and have already affected the vast majority of the world’s inhabitants. According to them, 85% of the world’s inhabitants already feel the effects of climate change.
However, the new work ignores several earlier ones, which showed that the rate of temperature change after the cometary bombardment 12,800 years ago was higher than today.
American scientists have summarized data on the ratio of isotopes of various elements in marine sediments over the past 24 thousand years. By the ratio of these isotopes, they estimated the rate and range of temperature changes over the specified period. It turned out that the ice age was even colder than previously thought, with the global average temperature of only plus 7° C. But the most unexpected conclusion of the work is different: according to it, the current climate warming is its fastest change in the last tens of thousands of years.
It is also very impressive that, according to the work, the increase in global temperatures by one degree in the last 100 years is the fastest temperature change in the last 24 thousand years. It was previously believed that 12,800 years ago, after the fall of a comet (or a series of comets) on the Earth’s surface and the subsequent “comet winter”, temperatures changed faster than today.
For example, this follows from the fact that literally in a matter of tens of years, the vegetation of Western Europe, which until then resembled modern one, suddenly changed to tundra. If the new work is correct, it turns out that the temperature changes in the world as a whole during this period were negligible. The researchers do not explain how this fits in with the avalanche-like drop in temperatures in Europe and North America.
In connection with the sharp contradiction of their statements to the data set, we should expect the release of additional works that will try to challenge the conclusions of the new one.
Rain will fall instead of snow in the Arctic soon – scientists
Scientists have conducted a study that showed that rainfall would soon replace snowfall as the most common rainfall in the Arctic. This will happen due to climate change and warming of the northern polar region of our planet, The Guardian reports.
Today, the Arctic receives more snow than rain. But by the end of the century, this precipitation will change places: much more rain will fall over the seas and land of the region than snowfall.
This will happen when the average temperature rises by three degrees Celsius. If the agreements reached at the recent Cop26 summit meet their targets, the temperature rise could be contained within 2.4 degrees Celsius. But even if the temperature rises by 1.5-2 degrees Celsius, there will be more rainfall in Greenland and the North Sea than snowfall.
Scientists have used the latest climate models, showing that the replacement of snow with rain will occur decades earlier than anticipated. Autumn will be the season with the most dramatic climatic changes. So, if carbon dioxide emissions do not decrease, more rain than snow will fall in the central Arctic in the fall, already in 2060-2070, and not by 2090, as previously thought.
According to the researchers, the consequences of such changes will be “serious” – from accelerating global warming and rising sea levels, to melting permafrost and massive starvation of reindeer. Scientists speculate warming the Arctic could exacerbate extreme events such as hurricanes, floods and heatwaves in Europe, Asia and North America.
“What is happening in the Arctic does not remain only there. You may think that the Arctic is far from your daily life, but in fact, the temperature there has increased so much that it will affect the south. We see an early transition to showers in the central Arctic, where it appears to be snowing in the fall. This will have serious consequences. The Arctic with stable snowfalls is essential for everything in this region, as well as for the global climate, as it reflects a lot of sunlight, ”said Michelle McChrystal of the University of Manitoba in Canada.
“The new models could not be clearer: unless warming is stopped in the future, the Arctic will become wetter, seas that were once covered in ice will open up, snow will rain,” said co-author of the new study, James Screen of the University of Exeter.
Scientists have long warned that rainfall in the Arctic will increase in the future as more water evaporates from warmer, ice-free seas. But a new study has shown that by 2100, there will be more rain than snow here.
Snow is essential for the appearance of sea ice in winter, so less snow means less ice and more heat being absorbed by the open seas. Research shows that rainfall is increasing in Greenland, accelerating the sliding of glaciers into the ocean and, as a result, rising sea levels, which threatens many coastal areas.
Most of the land in the Arctic is permafrost tundra, but more rainfall will change that.
“You are flooding the earth with warm water that can melt the permafrost, which will be a big problem because, as we know, it is a powerful carbon and methane sink,” McChrystal said.
All this will lead to the melting of important ice roads, flooding, and threatening local animals’ famine. When it rains on the snow and freezes, they cannot feed. Populations of reindeer and musk oxen that cannot reach the grass may be affected.
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Earlier, scientists from University College London said that the ice thickness of the Arctic coastal regions is shrinking much faster than previously thought. Researchers have conducted new simulations that show that this speed is actually 70-100% higher than expected.
It is high time for the former colonial powers of the world to take responsibility for the climate emergency they created. Let’s talk about climate justice and decoloniality here.