I recently finished the ecology unit in my biology 101 class. And to be honest, it scared the hell out of me. There are so many things that are going drastically wrong with the environment right now. For one, we are in the midst of the world's sixth mass extinction. There have been five mass extinctions in the history of the earth, the last one being the cretaceous extinction (where a meteor hit the earth and dinosaurs went extinct.) Well at this very moment, the world's sixth mass extinction is occurring- the sixth in 4.5 billion years. Species are disappearing at 1,000-10,000 times their natural rate. It is estimated that more than half of earth's species will be extinct by the end of the century- and experts estimate that 37 percent of the animal species on the planet will disappear by 2050, and 1 MILLION plant and animal species will have disappeared by the same time. 30% of all amphibian species, 23% of all mammal species, and 12% of all bird species are expected to go extinct by 2050. We are currently in the cenezoic era- the age of mammals. One scientist coined the term, "The eremezoic era", meaning in latin, the age of loneliness, and said that it would follow the age of mammals. With earth's biodiversity declining this rapidly, it is going to be humans and the species we need to survive left on the planet. Which is rather depressing, in my opinion. And once one species go extinct, you have no idea what effect it's going to have on species we need. Say, for example, a keystone species that pollinates plants goes extinct. We need angiosperms (flowering plants) to live. If we spent all our time pollinating plants to eat, all music, literature, art, etc. would come to a crashing halt.
The earth also provides $12 trillion worth of environmental services each year- ranging from air and water purification to erosion prevention to regulating the weather. 15 years ago, there was an experiment called Biosphere 2 (earth is biosphere 1). Biosphere 2 Center, in Oracle, Arizona, cost over $200 million to construct. It was an attempt to recreate not only a sustainable environment, but to reconstruct earth's major biomes- tropical rainforest, ocean, savannah, desert, marsh, and agricultural landscape- in 13,000m2 of land- a second biosphere. In 1991, eight scientists entered biosphere 2 and sealed themselves off from the outside environment. The experiment ended in disaster- nineteen of 25 verterbrates went extinct, and all pollinating insects went extinct- so the scientists had to pollinate all plants themselves in order to survive. "By 1993, the oxygen concentration in the air inside Biosphere 2 fell to 14%—roughly equivalent to that at the peak of a 17,500-ft mountain. Atmospheric CO2 rose to about 1700 parts per million (ppm), similar to a level last seen approximately 50 million years ago shortly after the extinction of the dinosaurs. Nitrous oxide (N2O), a trace gas emitted from the microbial decomposition of soil nitrogen, rose to 79 ppm—a level that can reduce vitamin B12 synthesis to levels that damage the brain." The scientists had to abandon the experiment not even two years after they started it. If we couldn't sustain 8 scientists for less than two years, how could we possibly sustain the whole planet? And even if we could, we don't have nearly enough money to do it- I read that it would cost 4 times the world's annual spendings.
Annnd don't get me started on global warming. The temperature has gone exponentially up with the carbon emissions of the last century. If we keep on the path that we are with our carbon emissions, we are screwed. A temperature increase of 2 degrees Celsius could raise the sea levels enough for more than 600 million (Environment and Urbanization reports 634 million people) to be displaced. And with the population going to increase to 9.3 billion by 2050, where do we have room for 600 million people? Two thirds of the world's cities, as well, are located in low lying coastal areas. Imagine Los Angeles and Seattle being wiped off the map. The repercussions of a sea level increase would be unfathomable.
I don't want to live in a world where half the current species are extinct, or one where my children play in the rain because of it's acidity level, or one where we don't have the forests we had 100 years ago, so let's make this world a more beautiful planet for the next generation, not one that's falling apart at the seams.