Global warming, why is there such cold weather in southern China this year?

First of all, global warming is a common phenomenon. In fact, the temperature in every part of the world does not generally rise every time, but it is only an average phenomenon, and the average temperature in the world has risen.

Second, one of the effects of global warming is climate anomaly. Global warming causes the global temperature and precipitation to be in an abnormal state, and the temperature, humidity and dryness change frequently, which easily leads to extreme abnormal weather.

The reference materials are as follows: Extreme weather events and various disasters have occurred in many parts of the world since this year. Since summer, many countries in the northern hemisphere have suffered from unprecedented high temperatures. Heat waves and floods hit many areas, while rare low temperature weather occurred in many countries in the southern hemisphere.

For a long time, a large number of scientists have been looking for the causes of abnormal weather and climate changes. According to the fourth assessment report issued by the United Nations Intergovernmental Panel on Climate Change in 2007, with the global climate change, the types, frequencies and intensities of extreme weather events will change. Although it will take a long time to verify the relationship between individual weather events and global warming, the World Meteorological Organization recently said that a series of disastrous weather events occurred recently are consistent with the speculation in the report of the United Nations Intergovernmental Panel on Climate Change, that is, extreme weather events are on the increase in the climate background of global warming.

El Ni? o and La Ni? a are the strongest signals of global climate anomalies, which has almost formed * * * knowledge in meteorological circles. El Nino is a "warm event" of global climate change, while La Nina is a "cold event" of global climate change. Some studies have pointed out that the quiet solar activity in recent 10 years, the abnormal sea surface water temperature in the Pacific Ocean near the equator, and the frequent occurrence of the negative phase of the Arctic oscillation index will also lead to abnormal weather and climate.

It should be pointed out that weather phenomena are produced by many factors through extremely complex interactions, and scientists' research on weather and climate anomalies is far from enough, and their explanations are still very limited. According to the assessment of the United Nations Intergovernmental Panel on Climate Change, 90% of the climate changes observed in the past 50 years may be caused by human activities. The scientific community generally agrees with this view, but this view does not scientifically evaluate the natural fluctuations of global and regional climate, especially the natural fluctuations of the climate system on the age scale, nor can it explain the phenomenon that the global average temperature has not continuously increased since 1998, let alone explain the temperature change characteristics in the period of high carbon dioxide concentration in the atmosphere in history. Therefore, some scientists believe that the current estimation of the sensitivity of the earth's climate system to human activities may be too high. It can be seen that the scientific community still lacks sufficient understanding of the future climate change trend.

We need to have a scientific understanding of weather and climate anomalies. Climate indicators always swing up and down at the normal level, and there are always anomalies in some areas. We should pay attention to these anomalies, but we should not treat an extreme weather event as a climate anomaly at will. Limited by the level of knowledge, some existing theories, viewpoints, evaluations and predictions are uncertain to varying degrees. Whether there will be more and more bad weather needs further research and analysis by scientists.

The earth is the only home for mankind. We should take active measures to minimize the possible impact of human activities on climate change. At the same time, in the face of the frequent occurrence of extreme weather, we should pay attention to its monitoring and forecasting research and establish an effective coping mechanism.