What impact will the rising temperature have on China's agricultural production?

Xinhua News Agency, Beijing, February 2 (Reporter, Yao) Affected by global warming, the temperature in most parts of China this winter is higher than normal. According to the monitoring data provided by China Meteorological Bureau, the national average temperature in June+10/October in 5438 was-4.5 degrees Celsius, which was higher than normal 1.4 degrees Celsius. In February last year, the temperature in the northern region was also higher than normal. Some experts said that although whether it is a warm winter depends on the weather in February, overall, the continuous high temperature in winter has become a trend.

What impact will climate warming have on agricultural production? Is it good or bad? The reporter interviewed relevant experts for this purpose. Song Lianchun, director of the Department of Forecasting and Disaster Reduction of China Meteorological Bureau, said that the high temperature in winter would have a double impact on agricultural production. High temperature is conducive to the overwintering of eggs and bacteria, which is easy to lead to the spread of pests and diseases in spring. At the same time, due to the dry winter climate in the northern region, it will also cause soil moisture loss, which may lead to spring drought in some areas. On the other hand, high temperature is conducive to the accumulation of land heat and has a favorable impact on the growth and development of winter crops such as rape in the south. The analysis of experts from Heilongjiang Biological Control Station also shows that climate warming provides favorable conditions for the survival of pathogens and the overwintering of pests, which is likely to bring very adverse effects on agricultural production in spring of 2007.

The El Nino phenomenon caused by climate warming has a deeper impact on agricultural production. According to climate experts, when the El Ni? o event occurs, China often suffers from drought in the south and drought in the north, and the probability of high temperature in winter is greater. 1998 is a typical "El Nino year". According to the monitoring of meteorological department in Jiangsu province, the temperature in this province was obviously high from 65438+ in February last year to 10 this year, which was obviously affected by El Nino. Climate experts believe that under the influence of El Ni? o phenomenon, it is easy to have continuous rainy weather in spring, which will affect the growth of food crops and even lead to a reduction in production.

Not long ago, the National Assessment Report on Climate Change issued by the Ministry of Science and Technology, China Meteorological Bureau and China Academy of Sciences pointed out that in the next 50 to 80 years, the national average temperature is likely to rise by 2 to 3 degrees Celsius, and the average precipitation will increase by 7% to 10%, but it will not change the trend of drought, especially in the north. As climate warming increases the demand for agricultural water, the regional differences in water supply will also increase. In order to adapt to the change of production conditions, the agricultural cost and investment demand will increase greatly.

Climate experts say that climate change will have a great impact on agricultural production in China. If no measures are taken, by the second half of the 20th century, the output of major crops in China, such as wheat, rice and corn, will drop by as much as 37%. In animal husbandry, the drought trend caused by climate change will increase the potential desertification trend in semi-arid areas, the grassland boundary may expand, the area of alpine grassland will decrease, and the distribution pattern of grassland carrying capacity and carrying capacity will change greatly.

According to the forecast of the National Climate Center, in February, the temperature in most parts of China was close to normal or high, with more precipitation in northern and western Xinjiang, central and western Inner Mongolia, central and eastern Gansu, Ningxia, eastern Qinghai, most of the middle and lower reaches of the Yangtze River, central and western Jiangnan, and southwestern and eastern regions. Meteorologists suggest that livestock in the pastoral areas of Northwest China and Inner Mongolia should strengthen cold protection and warmth, prevent snowstorms and other disasters in pastoral areas, and ensure the safe wintering of weak livestock and young livestock. Since June+10, 5438, there has been less rain and snow in most winter wheat areas in the north, and the moisture content has declined. All localities should prepare for drought as early as possible to avoid the occurrence of spring drought. "beginning of spring" is approaching, all localities should timely harrow wheat and intertillage to conserve moisture according to the weather changes, and apply more organic fertilizer in areas where conditions permit, so as to increase the temperature and conserve moisture and promote the timely growth of winter wheat.

Experts said that the high temperature and warm autumn caused by climate warming last summer affected agricultural production in China.

Xinhua News Agency, Beijing, February 2 (Reporter Wang Yu) Global warming caused by human activities is having an increasing impact on agricultural production. Lv Houquan, an expert in ecology and agrometeorology at the National Meteorological Center, said in an interview that the drought and high temperature in Sichuan and Chongqing last year and the high temperature in most autumn and winter crop areas had a great impact on crop growth.

Lv Houquan said that in 2006, the disastrous weather that had a great impact on agricultural production in China was mainly the summer drought and high temperature in Sichuan and Chongqing. The summer droughts in Chongqing and Sichuan are the most serious years since 195 1 respectively, with the characteristics of early occurrence, long duration, wide range, great disaster intensity and serious harm. The summer drought began in early July, earlier than normal 10 ~ 20 days, and ended in early September.

Lu Houquan said that the unusually high temperature in summer is the main factor leading to the rapid development of drought and the aggravation of the disaster. In 2006, the days of high temperature exceeding 35 degrees Celsius in most arid areas were 30-55 days, and the days of high temperature exceeding 40 degrees Celsius in some areas reached 10 days or even exceeded 44 degrees Celsius. From July to mid-August, the degree of less precipitation, the duration and intensity of high temperature in eastern Sichuan and most parts of Chongqing all reached the extreme value of the same period since meteorological records were recorded. The intensity and scope of drought are obviously larger than in previous years, affecting 22 counties and cities in Sichuan/KLOC-0 and 34 districts and counties in Chongqing, covering almost the whole Sichuan Basin, with intensity, scope and duration exceeding the same period in history. Crops suffered from high temperature and drought, which led to poor fruiting and grouting, and the grain yield was reduced by more than 5 million tons. The yield and quality of cash crops have also declined. At the same time, agricultural infrastructure has also been seriously damaged, which has a great negative impact on the sustainable development of agriculture.

Lv Houquan said that in autumn of 2006, the temperature in most winter crop areas in China was significantly higher than that in the same period of normal years. Warm autumn makes the wheat in the northern winter wheat area grow faster before winter, and some areas grow vigorously and have poor cold resistance, which may lead to freezing injury when it is cooled strongly. Especially in some areas with poor soil moisture, the wheat field is not tightly sealed, and when there is strong wind to cool down, it is easy to form freezing damage.

According to the outline of the fourth climate change assessment report issued by the United Nations, global warming is an indisputable fact.

Xinhua News Agency, Paris, February 2 (Reporter Lu) It is an indisputable fact that climate warming is caused by human activities. This is the main conclusion of the fourth climate change assessment report released by the United Nations Intergovernmental Panel on Climate Change (IPCC) on the 2nd.

The above conclusions provide a theoretical basis for decision makers around the world to determine effective measures to protect the environment as soon as possible. Experts pointed out in the abstract of more than 20 pages of the report that the observation of global average atmospheric temperature, average ocean temperature, melting of glaciers and snow, and the measurement of global sea level all confirmed that the global climate is warming.

Experts predict that from now until 2 100, the "most likely rising range" of the global average temperature will be 1.8℃ to 4℃, and the sea level will rise 18 cm to 59 cm, and the reason for this trend is "very likely", that is, at least 90% may be human activities.

According to the summary of the report, since 1750, the global content of carbon dioxide, methane and nitrous oxide has been increasing at an alarming rate, and it has far exceeded the level before the industrial revolution. The increase of carbon dioxide is mainly caused by human use of fossil fuels, while the increase of methane and nitrous oxide is mainly caused by human agricultural production activities.

Zheng Guoguang, deputy director of the China Meteorological Bureau and co-chairman of the International Earth Observation Organization, said that the outline published today is more scientific and less uncertain than the third climate change assessment report published in 20001year, which integrates the scientific research achievements of scientists from all over the world for more than six years.

Taking the prediction of sea level rise as an example, he said that when the third assessment report was drafted, there were only a few experiments in the scientific community, and this time it was based on 58 experiments conducted by 1 1 four climate assessment models used by countries. In addition, the prediction range of global temperature rise has also been significantly reduced, which shows that the scientific community has greatly improved its scientific understanding of climate change. In the third assessment report, experts predicted that by 2 100, the global average temperature will rise by 1.4 to 5.8 degrees Celsius, and the sea level will rise by 9 to 88 centimeters.

/kloc-29/0 to February 1 day, more than 500 experts from IPCC working group I met in Paris to revise the IPCC's fourth assessment report and draft the outline of the assessment report. Qin Dahe, director of China Meteorological Bureau, presided over the meeting as co-chairman of IPCC.

During this meeting, many cities, such as Paris, the French capital, turned off their lights and electricity for five minutes on the evening of February 1 to declare war on energy waste. The Eiffel Tower turned off all lighting equipment, and the buildings such as museums belonging to the city of Paris also lost power.

IPCC was established by the United Nations Environment Programme and the World Meteorological Organization in 1988. It has gathered more than 2,500 experts from all over the world, and the Committee is divided into three working groups. So far, IPCC has published three assessment reports on global climate change. The full text of the fourth assessment report will be published in the second half of this year.