The global warming that has been observed for 150 years is unprecedented, according to research conducted by American scientists. The analysis was performed using a computer simulation based on data from marine sediments.
Scientists from the University of Arizona, Washington and the National Center for Atmospheric Research have reconstructed the history of changes in global temperature over 24,000 years. Their analyzes, carried out with the use of computer climate modeling, show that the main driving force behind the changes taking place since the last ice age is the increasing concentration of greenhouse gases and the retreat of ice caps.
In addition, there is a general trend of increasing temperatures over the past 10,000 years, the authors of the study report. The conclusions were published in the scientific journal “Nature”.
Climate change. The model covers 24,000 years
According to researchers, the rate and scale of climate warming over the last 150 years has exceeded that of the last 24,000 years. – This reconstruction suggests that the current temperatures are unprecedented for a period of 24,000 years. It also suggests that human-induced warming is happening faster than any other during this time, explained Professor Jessica Tierney, the author of the study, known for her contribution to the reports of the Intergovernmental Panel on Climate Change. “The fact that we are so far removed from a state we would consider normal is cause for alarm and everyone should be wondering,” added Dr. Matthew Osman in charge of the study. The team produced a 24,000-year model of climate change with an accuracy of 200 years that also takes into account different areas of the Earth. Dr. Osman said that with these maps, anyone can see temperature changes in different parts of the Earth – on a very personal level. – For me, the possibility of visualizing the 24,000-year-long evolution of temperatures in the location where I am sitting now or where I grew up really helped me feel how serious the climate change is today – said the specialist.
Climate change. Global temperature research
His team used two methods to create their model. The scientists used the data from the study of marine sediments to develop a computer simulation. Temperature can change the chemical composition of the remnants of once living organisms present in the sediments. Computer simulations, on the other hand, are based on the current understanding of the physical processes taking place in the climate. These methods are not perfect, but they can be used, say the researchers. They add that the combination of the two approaches made it possible to use the strengths of both of them. A similar method is used, for example, in weather forecasting. ‘To predict the weather, meteorologists start from a model that describes the present weather, add observations of temperature, pressure, humidity, wind direction and so on to make an ongoing forecast, explained Professor Tierney. ‘In this way, we were able to use the advantages of both unique data sources to create an observationally limited, dynamically coherent and spatially complete reconstruction of the past climate, explained Dr Osman. Scientists are now working on recreating temperatures even more distant in the past. “We are excited to apply this approach to an old climate that was warmer than it is today. This is because these times are a window to our future if greenhouse gas emissions increase, Professor Tierney said.
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