The two most serious threats facing the world are global warming and the '6th extinction'. Both are man-made threats. The world is warming up due to the accumulation of carbon dioxide and other greenhouse gases spewed out by mainly by motor vehicles and factories.

Global warming will change the climate all over the world with unknown consequences. But, given that plants and animals, including humans definitely, have adapted to a particular climate-influenced environment, we can expect major upheavals when the climate patterns shift.

By 2080 it is believed that the summer ice cover of the Arctic will be completely gone. Since ice reflects away sunlight thus cooling the planet, without it, the earth will warm up further. Also the melting of the ice will add a lot of fresh water into the northern oceans.

This could stop the flow of the Gulf Stream bringing warmth from the tropics to Europe and North America. These areas could then experience massive cooling that could make them unlivable. The paleo-record suggests that when the outflow of water from the Arctic Basin hits a critical level of freshness, the global ocean circulation changes dramatically, as reported by the Scientific American magazine.

The process is on its way. Over the past 60 years, the discharge from Russian rivers into the Arctic has increased by 7 percent, and it is compounded by a record amount of melting from the Greenland Ice Sheet and Alaskan glaciers.