2023 Author: Bryan Walter | [email protected]. Last modified: 2023-05-21 22:24
2018–2022 is highly likely to be warmer than average, with an increased risk of temperature extremes. These conclusions were reached by the authors of a new algorithm for long-term forecasting of climatic conditions, which published a study in Nature Communications.
Generally, global climate models describing the dynamics of the atmosphere and ocean are used to predict long-term climate change on Earth. They lay down certain scenarios for the development of events - in particular, how much greenhouse gases will enter the atmosphere. The forecasting horizon for such models is tens of years, and scientists can predict the climate for the middle or the end of this century. For example, recently, using climate models, an international team of scientists showed how climate change will increase the number of victims of heat waves.
Florian Sevellec of the University of Brest and Sybren Drijfhout of the University of Southampton developed a probabilistic climate prediction algorithm based on the Perron-Frobenius operators that are used to describe the state of a chaotic dynamical system. Scientists emphasize that it takes "hundredths of a second on a laptop" to complete the calculations, which could make climate forecasting more accessible.
To train the algorithm, the authors used real data and forecasts of 10 climate models for the XX and XXI centuries. According to scientists, their system quite accurately reproduced the slowdown in warming observed at the beginning of the century, and in terms of accuracy and reliability it is not inferior to the current forecasting methods.
The authors of the algorithm write that in 2018–2022, natural climate variability will enhance the long-term warming trend due to human activities. This will lead to the fact that the global average air temperature will be higher than the multiyear averages. True, the value of the "additional" average warming is calculated in hundredths of a degree: for example, for 2018–2019, this anomaly will be 0.03 and 0.07 degrees for land and ocean temperatures, respectively. The likelihood of periods of extreme heat will increase slightly, while periods of abnormal cold weather will, on the contrary, decrease. In addition, due to more pronounced warming in the ocean, some increase in the activity of tropical hurricanes is possible.
“This is a forecast of globally averaged values, annual averages, as I understand it. That is, there is no need to talk about any regional anomalies. Moreover, taking into account all our modern knowledge, we can confidently say that the global positive temperature anomaly will be accompanied by regional negative anomalies in some weeks or months,”noted a senior researcher at the Institute of Atmospheric Physics named after A. M. Obukhov RAS Alexander Chernokulsky, commenting on the study for N + 1.
The authors of the article are going to increase the spatial resolution of their algorithm in order to make predictions for specific regions, and not for the entire globe. In addition, after refinement, it will be possible to predict other parameters of the climate system in addition to the average air temperature, for example, the amount of precipitation.
“In general, the approach is interesting, perhaps it can be used for regional forecasts. But this is not obvious, since the authors impose very serious conditions, namely, that information about the global temperature is sufficient to predict the global temperature, that is, the variable can predict itself. That is, for regions or other variables, when one variable is determined by many others, it may no longer be applicable as presented, "Chernokulsky said. According to him, if it is possible to determine the relationship between the global temperature and the parameters of interest to scientists, for example, the likelihood of drought in southern Russia, such a forecast may be of certain interest.
According to preliminary data, 2018, including due to an abnormally hot summer, may take the fourth line in the list of the warmest years since the beginning of instrumental weather observations - the first three positions are now occupied by 2016, 2015 and 2017. At the same time, in this case, the account goes to those very hundredths of a degree, that is, even such a slight deviation can bring this or that year to the first place.
