At present, the global temperature change discussed by the international community mainly refers to

At present, the global temperature change discussed by the international community mainly refers to the long-term trend change of the global climate system, including the rise of the earth's surface temperature and related climate phenomena and effects.

The following is a detailed analysis of this problem:

1. What is global temperature change?

Global temperature change refers to the long-term trend change of the earth's surface temperature, which is mainly reflected in the rise of the earth's temperature. In the past few decades, the global temperature has been rising continuously, which has aroused widespread concern and discussion. This rise is related to greenhouse gas emissions caused by human activities, which has a great impact on the earth's ecosystem, social economy and human health.

2. Greenhouse gas emissions and warming effects:

The main greenhouse gases include carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O). These gases can absorb and re-radiate the infrared radiation on the earth's surface, leading to the accumulation of energy in the earth's atmosphere, thus causing the warming effect of rising temperature. Human activities, especially the increase of industrialization and energy consumption, lead to a large number of greenhouse gas emissions, which further intensifies the trend of global warming.

3. Factors affecting global temperature change:

In addition to man-made greenhouse gas emissions, global temperature changes are also affected by many factors, including solar radiation, ocean circulation, volcanic activity and other natural factors. The change of solar radiation and ocean circulation can affect the trend of global temperature to some extent. In addition, volcanic eruptions will release a lot of volcanic ash and aerosols, which will have a short-term impact on the climate.

4. Effects and consequences of global temperature change:

Global temperature rise has caused a series of climate changes, including the increase of extreme weather events, rising sea level, melting glaciers and disturbance of ecosystems. These changes have had a wide impact on human society and natural environment, such as agriculture, water resources and biodiversity, and brought a series of environmental and economic challenges.

To sum up, the problem of global temperature change refers to the long-term upward trend of the earth's surface temperature, and its reasons mainly include greenhouse gas emissions caused by human activities and the role of natural factors. This problem has brought a wide range of impacts and challenges to the global ecosystem, economic development and human society, so it needs the cooperation and efforts of the global community to deal with and mitigate its impact.