Climatologists have analyzed the temperature variations on earth over the last two million years, and came to the conclusion that on the planet today reign the highest temperature for the last 120 thousand years.
If the climate today works the same way as in the past, our CO2 emissions will raise average temperatures on Earth by 1.5-2 degrees, as shown by climate models, and at least 4 degrees Celsius, even without considering future emissions, said Carolyn Snyder (Carolyn Snyder of Stanford University (USA).
Snyder came to this conclusion and saw how varied the climate of the planet in the last two million years, studied approximately 60 samples of marine sedimentary rocks extracted from different parts of the world ocean.
Explains Snyder, ” deposits of shells of plankton, shellfish and other types of sedimentary rocks are a kind of climatic records, which are very clearly reflected how varied the climate of the Earth at a time when they were formed.
For example, the proportion of heavy and light isotopes of oxygen can tell us about the temperature fluctuations on Earth, the concentration of heavy carbon on biodiversity and mass extinction, and the proportion of calcium and other metals on the acidity and other properties of the oceans. Some rare elements, for example, beryllium-10, allow scientists to accurately determine the supernova and periods of abnormal activity on the Sun affecting the climate.
Studying these indicators, Snyder managed to get the data, what was the temperature of the Earth in 20 thousand time points, which she used in order to obtain a complete picture of cooling and warming in the past, and on the changes in greenhouse gas concentrations during this time.
Her calculations show that the Earth’s climate in the middle Pleistocene gradually became more and more cold, and about 1.2 million years ago, it stopped cold. The Earth’s climate began to live in 100-year cycles, the average temperature during the peaks which differed by 5-10 degrees Celsius.
The last peak there were 120 thousand years ago, and at that time the temperature on Earth was above average today by 3.5 degrees Celsius. Now the Earth is moving towards a new peak temperature and, as expected, Snyder, the temperature of the planet will grow, given trends of the past 1.2 million years, not 1-2 degrees, and 4 to 7 degrees as a result of human activities.
It is not clear how these extra degrees will affect currents in the Pacific ocean, which, according to Snyder, run these 100-year climatic variations, and whether human activity is to break these cycles, conducting the climate of the planet for over a million years.