The impact of the increase in greenhouse gases on the climate and ecosystem is a more complex issue. Although the increase in carbon dioxide is conducive to increasing the photosynthetic products of green plants, the changes in temperature and precipitation caused by its increase will affect and change the climate production potential, thereby changing the primary productivity of the ecosystem and the land carrying capacity of agriculture. This indirect impact on ecosystems and agriculture due to climate change may greatly exceed the direct impact of carbon dioxide itself on photosynthesis. According to the results of climate simulation experiments, doubling the carbon dioxide may cause tropical expansion, shrinking subtropical, warm tropical and frigid zones, slightly increasing cold temperate zones, increasing the area of grasslands and deserts, and reducing the area of forests. Carbon dioxide and climate change may affect a series of issues such as agricultural planting decision-making, variety layout and variety improvement, land use, agricultural investment and technological improvement. Therefore, when formulating national development strategies and long-term agricultural plans, the background of climate and environmental changes that may be caused by the increase in carbon dioxide should be considered. This problem is particularly important and urgent for my country, which is facing the two major pressures of population expansion and poor per capita resources.
