听力原文： Welcome to this lecture on Agriculture and the Environment. I hope it is enough to make some of you decide on a career in the field of agricultural science. As you all know, food is a basic human need and producing enough of it is the single greatest challenge facing the modern world. Developing nations have rapidly expanding populations so agriculture should be central to any development agenda for those countries. What's more, 75% of people in the developing world are dependant, directly or indirectly, on agriculture for their livelihood. And, for many low-income countries, it's the most important sector of the economy accounting for 50% of GDP and sometimes it's the primary, if not only, source of foreign currency. Now, of course, when I talk about ' agriculture', I am using the term to encompass more than just growing food crops. Of course livestock farming, fishing and forestry are included. In order to combat wide-scale food shortages agricultural research programmers are underway in many areas. Using science is one way to increase productivity; but, a word of warning: agriculture must also be sustainable. Let's look at approaches that are not sustainable. Firstly, overgrazing and intensive cropping are two ancient but destructive practices that lead to loss of soil fertility. Secondly, the modem idea of liberal application of chemical pesticides and herbicides has had disastrous consequences for the health of the land, ranging from the pollution of water sources to the destruction of wildlife. These practices have ignored the mechanisms that sustain ecological communities. Ignorance has led to the destruction of the very biodiversity that is essential for sustainable food production. However, introducing new agricultural techniques, especially things like genetic engineering, can be difficult because many people remain suspicious of the fact that plants have had their genetic material modified by scientists. Biotechnology has also led to the dubious practice of bio-prospecting, or as some prefer to call it, bio-piracy. Foreign multinational companies have been accused of illegally obtaining samples of indigenous plants of other countries in order to get their hands on genetic material to improve the quality or yield of their own crops. We must put aside the controversy surrounding the field of agricultural biotechnology in order to concentrate on the biggest threat to food production on this planet...which is...? Yes, climate change. The effects of global warming so far have been to shrink the food supply thereby pushing up prices and making, even the most basic necessities, unaffordable. As I see it, the international community must address this, and other challenges to agricultural production, with urgency. Concrete scientific and technological achievements need to be presented for farmers to evaluate and learn to use but, apart from that, governments need to address the complex issues of policy development if the world's hungry are to be fed. Environmental policies need to be put in place to protect ecosystems and correct soil degradation where possible. Countries cannot continue to exploit na~Lral resources whilst ignoring the consequences. In fact, I'd like to see teams of agriculture and environment experts making up a global network which would monitor the world's farming systems. Different farming systems should be studied not only with a view to analyzing the environmental effects, but the social and economic effects as well. The studies would be carried out with a view to stemming pollution and erosion and promoting safe, cost-effective practices that will guarantee a secure food supply in the future. Monitoring sites would need to be set up all across the world and data collected in a systematic way. Of course, building the online infrastructure for such a project would cost millions of dollars and there would be ongoing costs involved with the monitoring system but the information gathered would go a long way towards solving the problem of feeding the masses and ensuring millions of people don't face a hungry future. Complete the notes below. Write NO MORE THAN TWO WORDS for each answer. Agriculture and Environment (31) production = biggest problem in today's world Agriculture is important for jobs, exports and foreign exchange 'Agriculture' means: growing crops raising animals (32) (33) Agriculture must be sustainable: old methods, & new, chemical methods are all unsustainable→ (34) of biodiversity Biotechnology→GM or GE→ bio-prospecting (bio-piracy) i.e. large companies steal samples of native plants to use the (35) for their own crop improvement (36) is responsible for less food and higher prices Farmers need to be educated but governments also need to pay attention to (37) in order to protect the environment and re-nourish the soil Experts from around the world could come together to form. a (38) to observe farm systems aiming to prevent pollution and erosion and encourage safe procedures that are also (39) Creating the project's (40) would be very expensive and more money would be needed for the monitoring system but it could solve the problem of food shortages (31)