LESSON_PLANS
- OUR_ENVIRONMENT - MEDIA_ROOM
- FREE_SAPLINGS
OUR ENVIRONMENT
Mankind's
first experience with harm from air pollution probably came from the fires
they built in poorly ventilated dwellings. Since then we have gone on
to pollute most of the earth's surface. Until recently, environmental
pollution problems have been local and minor because of the Earth's own
ability to absorb and purify minor quantities of pollutants through the
photosynthesystic process naturally occuring in most of the Earth's plantlife.
The industrialization of society, the ever-growing and expanding use of
motorized vehicles, and the explosion of the population, are factors contributing
toward the growing air pollution problem. At this time it is urgent that
we find methods to clean up the air.
The primary air pollutants found in most urban areas are carbon monoxide, nitrogen oxides, sulfur oxides, hydrocarbons, and particulate matter (both solid and liquid). These pollutants are dispersed throughout the world's atmosphere in concentrations high enough to gradually cause serious health problems. Serious health problems can occur quickly when air pollutants are concentrated, such as when massive injections of sulfur dioxide and suspended particulate matter are emitted by a large volcanic eruption.
James Baker, undersecretary of the U.S. National Oceanic and Atmospheric Administration, and Peter Ewins, head of the British Meteorological Office, sent a joint letter to London’s "Independent" newspaper warning that "our climate is now changing rapidly and it’s important we take action now". The letter’s frank tone breaks with the conservative approach normally adopted in public by climate change scientists traditionally reticent about venturing into the political arena. "We’re now coming clean and saying we believe the evidence is almost incontrovertible, that man has an effect and therefore we need to act accordingly. As the average temperature goes up we can expect more extreme events — floods, drought, more severe storms. We now need to persuade the business community that to act now is the responsible thing to do". They said that expanding energy efficiency and renewable energy presented profitable opportunities for businesses trying to pump less carbon dioxide into the air.
The American Petroleum Institute, the industry's trade group, states: "While consensus on climate change remains a work in progress, we do know enough to take the risk seriously and to rule out inaction as an option".
The National Academy of Sciences said global warming could lead to "large, abrupt and unwelcome" changes in the climate, and the Intergovernmental Panel on Climate Change (IPCC) — which is made up of 2,500 scientists — warns that human-induced global warming could cause average temperatures to rise by up to 10 degrees in less than 100 years.
Greenhouse gasses are accumulating in Earth's atmosphere as a result of human activities, causing surface air temperatures and subsurface ocean temperatures to rise. Temperatures are, in fact rising. The changes observed over the last several decades are likely mostly due to human activities. We can't exclude the possibility that natural variability has contributed as well--but the main point remains--the earth is warming, and humans must accept some responsibility for that warming.
It won't take the greatest extremes of warming to make life uncomfortable for large numbers of people. Even slightly higher temperatures in regions that are already drought or flood-prone would exacerbate those conditions. In temperate zones, warmth and increased CO2 would make some crops flourish — at first. But beyond 3° F. of warming, says Bill Easterling, a professor of geography and agronomy at Penn State and a lead author of the IPCC report, "there would be a dramatic turning point. U.S. crop yields would start to decline rapidly". In the tropics, where crops are already at the limit of their temperature range, the decrease would start right away.
Mankind must turn to renewable forms of energy — because of dwindling oil supplies and because of the mounting and unimpeachable evidence that we have a profound carbon problem on our hands; that even if we discover billions of new barrels of oil in the ground, we cannot keep burning them — and pumping vast amounts of carbon dioxide and other so-called greenhouse gases into the atmosphere — without potentially catastrophic consequences.
According
to the latest findings of the United Nations Intergovernmental Panel on
Climate Change, in order to stabilize greenhouse gases in the atmosphere,
global emissions must be reduced to at least 60 percent below 1990 levels.
That is a radical change in the way the world uses energy. And to accomplish
that, many people feel, will require nothing less than a new industrial
revolution, an overwhelming retreat from society's mass reliance on the
carbon fuels — oil, gas and coal — that have powered the global
economy for more than a hundred years.