世界那么大，净土有几何.doc

世界那么大,净土有几何
一直以来,人类不仅从环境中获取资源,还习惯于把环境当成垃圾场,向其中直接排放废气、废水、固体废弃物。从天空到陆地,从河流到海洋,哪里有人类的足迹,哪里就少不了污染。然而,世界这么大,总有人类到不了的地方,我们还能否心存一丝希望―在这个星球上,尚有逃过人类破坏的一方净土?答案也许会让人失望……
Pollution, by definition, is something introduced into the environment that harmfully disrupts it. While nature sometimes produces its own damaging contaminants1)―wildfires send up billows of smoke and ash, volcanoes belch2) noxious gases―humans are responsible for the lion’s share3) of the pollution plaguing the today.
Wherever we go, we seem to have a knack4) for leaving our rubbish and waste behind. Visit even the most remote outpost on the and you will witness this first hand5). Still, the world is a big place. Might there be some last holdouts free from the taint of our pollution? Answering that question works best if we break down the environment into6) four realms―the sky, land, freshwater and ocean.
Sky and Land
Air es in many forms. Smog is posed of particulate matter7) and ozone. And its impact on human health and the environment can be severe. In India alone, ozone pollution causes crop losses equivalent to $ billion per year. In terms of human health, outdoor air pollution costs an estimated one million lives per year, while air pollution produced in homes―usually a by-product of cooking fires―kills around two million people annually.
When carbon monoxide, nitrogen dioxide and other primary pollutants (those that are injected directly into the atmosphere) find their way high into the atmosphere, they often get transformed through chemical reactions into what scientists refer to as secondary pollutants. Some of these pollutants can linger for months. Others, like methane8), are less reactive and may circulate the globe for years until they are eventually broken down or find their way to the ground via snow or rain.
Pollution expelled into the air gets transported vast distances by winds and atmospheric currents. For instance, Indonesia has recently been clearing large tracts