為什麼氣候變化不能忽略

嚴厲審查,委托英國總理上周在去年7月,出版,是有史以來最全麵研究氣候變化的經濟學。它不是一些歇斯底裏的環保主義者咆哮。這是一個冷靜的警鍾,還有他們的頭埋在沙子裏。它說,氣候變化是世界上最大的市場失敗。工業化前的水平大氣中溫室氣體的二氧化碳當量280 ppm(當量二氧化碳)。當前濃度430 ppm當量二氧化碳。有增無減氣候變化引起的二氧化碳排放,提高平均氣溫的風險/ 5 c從工業化前的水平。最新的科學證據,經濟對人類生活和環境的影響和適當權重的影響,評估估計損失可能相當於國內生產總值(GDP)的20%或更多。這些變化也將改變地球的自然地理。農業實踐將是災難性的改變得麵目全非在世界的許多地方,在聯合國目前的氣候變化會議在內羅畢證實。 But there has been little focus on the role of agriculture in climate change. Both agriculture and the food industry are not major producers of CO2 emissions. In the UK agriculture is responsible for just 2.5 per cent of CO2 emissions. It is the effect, rather, of climate change on these sectors that can no longer be ignored. A temperature increase of just 2C would dramatically decrease productivity in many parts of the world. Such a rise might raise agricultural productivity in colder climates no one really knows for sure. But the net effect would likely be a decline in output especially in the poorer south. What's more, low-lying agricultural areas will increasingly be more susceptible to flooding. This will pose a significant challenge to farmers especially as most attention will be focused on protecting built-up areas rather than the countryside. All this with a global population of 6 billion, estimated to touch 10 billion within the next few decades, in need of food. Up until now it has been relatively simple to dismiss climate change as a natural phenomenon, or even as a grossly exaggerated problem. Even today, no scientist can predict exactly how much temperatures will increase in the near future, or how the planet will respond. But what is emerging is a growing consensus that doing nothing will be a hell of a lot more expensive than taking preventative action. The Stern review estimates that the costs of action to reduce greenhouse gas emissions to avoid the worst impacts of climate change can be limited to around 1 per cent of global GDP each year. People would pay a little more for carbon-intensive goods, but economies could continue to grow strongly. Reducing emissions will make us better off, and stave off the threat of food scarcity. According to one measure, the benefits over time of actions to shift the world onto a low-carbon path could be in the order of $2.5 trillion each year. Agriculture policies and practices will have to meet changing climate regimes. A significant transition toward biofuels over the next 50 years is needed, with agriculture and forestry among the leading sources for both liquid and solid fuels. Crops such as sugar cane, corn and soybean are already being used to produce ethanol or bio-diesel. But above all, the agriculture and food sector needs to become engaged in the debate. It must find its voice. It is not a big polluter or emitter of CO2, but it will be one of worst hit sectors if climate change is not tackled. Tackling climate change now is the only option. Ignoring it will undermine economic growth - and contribute to food scarcity. Anthony Fletcher is the editor of FoodNavigator.com and is a specialist writer on food industry issues. With an international focus, he has lived and worked in the UK, France and Japan. If you would like to comment on this article please e-mail anthony.fletcher@decisionnews.com.