A dying planet? BEFORE READING 1 The title of this Module is Hot Issues . What hot issues do you think will be discussed in this Module? 2 The title of this Unit is A dying planet? What does this title mean to you? What do you think will be discussed in this Unit? The present state of our planet Humans are the most numerous species on Earth (except for insects): about 6.8 billion in 2009 and estimated to reach 12.5 billion by 2050, with the greatest growth in developing countries. Humans use approximately 40% of the Earth s terrestrial surface and their activities have made profound changes in the planet s atmosphere, soils and water. Today even the remotest places cannot remain untouched by what happens in other places: this is globalisation to the extremest degree. Globalisation means much more than multinational companies and advanced communication technologies. It also means rapid and frequent travel between countries: today s mass tourism can have tremendous effects on local environments and peoples. In addition, worldwide shipping of plant and animal products can give opportunities for illnesses and diseases to spread rapidly and reach global proportions creating pandemics, epidemics that affect the entire world. The impact that humans have made on the Earth, particularly since the Industrial Revolution, is alarming. Fossil fuels such as coal and petroleum may run out in the next 50 years. Since 1850 there has been a 28% rise in carbon dioxide emission levels in the atmosphere and a rise in median global surface temperature of more than 1 degree Celsius. The stratospheric ozone layer (which protects the Earth from dangerous ultraviolet rays) has been damaged by human CFC (chlorofluorcarbon) emissions to the point that each year a large hole more exactly a great thinning appears temporarily above Antarctica, and the overall global layer appears to be thinning as well. Humans have already tapped over 50% of the planet s accessible water; many of these sources suffer from pollution, overexploitation and/or political conflict. 60 to 70% of the world s marine and fresh water fish stocks are near depletion. Salinisation affects one-third of the globe s irrigated land; soil erosion has caused a 13% drop in worldwide crop production since World War II. Large-scale, single-crop farming means a reduction in plant genetic diversity leaving crops and farmers vulnerable to natural or human-generated problems that lead to greatly-fluctuating prices for agricultural products. module 8 Unit More than 19,000 plant species and 5,000 animal species are presently classified as in danger of extinction a situation generally caused by air and/or water pollution, loss of habitat, interruptions in their food chains. Our large human brains got us into this disastrous situation. The next question is: can they get us and our planet out of it? Florida tomatoes spoiled by a freeze: genetic uniformity increases production but makes plants vulnerable.