Temperature fluctuations and climate change
The highest temperature in the world was measured in the Death Valley in California (56.7oC), and the lowest - in Antarctica (-89.2oC). For Bulgaria these values are respectively: + 43.2oС (measured in the town of Sadovo) and -39.3oС (measured in the town of Trun).
The concept of the average temperature of the planet at first glance seems strange, since the Earth surface temperature fluctuates widely in different regions, during the seasons, as well as during the day and night. For example, if some parts of the Earth are cold (as in winter in the Northern Hemisphere), then other parts are warm (as in summer in the Southern Hemisphere).
Then, to talk about the "average" temperature of the Earth does not seem so reasonable?
However, the concept of global average temperature is convenient for tracking and analyzing changes in the energy balance of the Earth – how much solar heat it absorbs and how much it radiates back into Space.
To calculate the global average temperature, scientists measure the temperature in places scattered around the world. In inaccessible areas where no measurements are made, they use ambient temperatures and other information to estimate missing values. Numerous independent research groups perform their own analysis of the values to determine the average temperature for the studied area, after which the data are pooled and used to calculate the average global temperature of the Earth. This process provides a consistent and reliable method for monitoring the changes in the temperature of the Earth surface over time.
The results are unequivocal – the temperature of the surface of the Earth shows an upward trend. For example:
- The temperature of the Earth has risen with 0.08oC per decade since 1880, but the rate of warming has more than doubled in the last 40 years – 0.18oC per decade.
- Globally, 2016 has been the warmest year since the temperature measurements of the Earth began.
- The decade 2011-2020 was the warmest decade in history.
- According to the Global Climate Report 2020 of the US National Oceanic and Atmospheric Administration, 2020 has been ranked as the second warmest year for the last 141 years since the Earth surface temperature measurements were made. Many parts of Europe and Asia were at record levels, including most of France, northern Portugal and Spain, much of the Scandinavian Peninsula, Russia and Southeast China, and most of the Atlantic and Indian Oceans, as well. The heat has reached as far as Antarctica, where the station at the Esperanza base measured the highest temperature of 18.4oC on February 6, 2020.
The rising of global average temperatures is a major factor in climate change and global warming. The reason is the human activity, as a result of which emissions are increasing greenhouse gases.
Climate change is affecting all regions of the world, having a strong impact on the ecosystems and habitats of plant and animal species. Since the climate patterns are dynamic, terrestrial and marine habitats change and become unfavorable to some species, while allowing others to "conquer" new areas, displacing native species. In some cases, entire ecosystems are at risk of collapse. For example, polar bears may become extinct in the near future. These animals use sea ice as a floating platform to catch prey. Studies show that Arctic sea ice is melting at a rate of 9% per decade, threatening the habitat and existence of polar bears.
