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Climate knowledge was calculated using the “backwards” method, exactly how much lower the Earth average was at the time of the glacial maximum 20,000 years ago, that is, at the end of the ice age.
An open question: exactly how cold was it in Wrm-glacilis?
The research team, led by the University of Arizona, found the last ice age 20,000 years ago in a 7.8C global glacier. Among other things, the results contribute to a better understanding of the relationship between the increase in carbon dioxide levels that can be experienced today and the average global temperature; let’s start investigating.
The last ice age was a time in the history of the Fld when huge glaciers were covered.
North America, large areas of Europe and South America and many parts.
At the same time, cold-adapted plants and animals began to flourish around the world.
“We have a lot of data on this period because we study so quickly,” said Jessica Tierney, a researcher in the Department of Science at the University of Arizona.
A question that science has been able to answer while remaining open: exactly how cold was the ice age? “
Tierney is the leader to get the Nature The last problem is that the ice age tlaghmrsklete globli was about 6 degrees Celsius lower than the mainl.
The context was popular: the 20th century global tlaghmrsklete was around the 14th century. “From our point of view, 6 degrees may not seem like a big difference from our point of view, but globally it is a big difference,” Tierney said.
They heat up earlier at higher altitudes.
Along with his research, he also provided accurate information on how the temperature developed in some parts of the world. “The intermittent areas of North America and Europe were covered with ice and it was very cold in these regions. But even in Arizona, there was a lot of eruption, Tierney explained.
“Strong winds, such as the Technical Arctic, were the most affected by the cold: here it was 14 ° C colder than today.”
The results are consistent with our most recent knowledge of how the Earth’s Arctic is responding to climate change. “Climate models predict that high geographic latitudes will warm earlier than low latitudes,” continues the researcher.
If we look at the forecasts for the future, we think that the climate is the one that is warming the most from the technical poles. This phenomenon is known to polar science as polar amplification. This is exactly what happened in the last glacile maximum time, with only the opposite sign. Higher widths are simply more sensitive to climate change, and this will not happen again in the future. “
The level of carbon dioxide was very low at the time of the greatest ice age.
Knowing the exact temperature of the ice age is important because it can be used to calculate the carbon content of the climate, that is, to what extent the global temperature contributes to the change in the amount of carbon dioxide in the ice age.
Tierney and his team estimate that global carbon dioxide levels are responding to every doubling of global temperature growth by 3.4 ° C.
This value is located in the middle of the range estimated by the latest generation of climate models (1.8 – 5.6C).
During the last ice age, Igkri’s carbon dioxide level was about 180 ppm (parts per million), which is a very low number. At the time of the Industrial Revolution, this value had increased to 280 ppm, and by that time it had reached the level of 415 ppm.
“The award agreement wanted to set the maximum rate of warming at 1.5 ° C compared to the pre-industrial level, but given the current growth rate of carbon dioxide
it seems extremely difficult to avoid overheating above 2 ° C
Tierney pointed out. “Now we have achieved a warming of more than 1.1ºC, but the less this process progresses the better, because the Fld is in fact very sensitive to changes in CO2 levels.
Ceni fossil plankton like the heat of the past
Since there were no temperatures at the time of the ice age, the researchers had to develop models to translate the fossil plankton data into marine values.
The fossil data was then combined with the latest glacil maximum climate model simulation using a method called data assimilation and widely used in weather forecasting.
Meteorologists do this by measuring the current temperature, pressure and content, and trying to predict the weather for the moment by inserting this measurement data into the model. We use the Climate Model from the National Air Research Center in Boulder, Colorado, to
to get to a kind of reversion to the ice age climate:
we load the results of the current measurement into the model and run the simulation backward in time to find out what the weather might have been like then. “
Tierney’s team is planning to be in the future
With the help of the same technique, we will reconstruct the warm episodes of the Earth’s past.
“If we can revive the hot weather of the past, we can begin to answer important questions about how the Earth responds to very high levels of carbon dioxide, and we can learn more about what to expect from future climate change.”
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