Cities are growing at an unprecedented rate. Half the Earth's population will soon live in congested, urban regions mainly in the poor, developing countries. If the 20th century was the century of urban sprawl, the 21st century will be the century of the mega city. A mega city is defined as a city with an estimated population of more than 10 million people.
The 10 largest mega cities in the world as of the year 2000 are:
1. Tokyo, Japan 26.4 million
Currently, there are an estimated 23 mega cities worldwide. By 2015, the number of mega cities is expected to grow to 36. Today, Asia has 9 mega cities; Beijing, Bombay, Calcutta, Jakarta, Osaka, Seoul, Shanghai, Tianjin and Tokyo- and it will soon have 4 more, including Bangkok, Dhaka, Karachi and Manila. Relative to their level of development, Asia has a greater proportion of their urban population in mega cities than in any other region in the world. The world's mega cities take up just 2 percent of the Earth's land surface, yet they account for roughly 75 percent of industrial wood use, 60 percent of human water use, and nearly 80 percent of all human produced carbon emissions. These figures suggest that the struggle to achieve an environmentally sustainable economy for the 21st century will be won or lost in the world's urban areas.
It is projected by international development agencies that more than 300 cities with over a million inhabitants will have formed in our world by 2025. Between 1990 and 2025, the number of people living in urban areas is projected to double to more than 5 billion- 90 percent of that increase will occur in developing countries. The explosion and growth of mega cities worldwide is unsustainable, unprecedented and ecologically disastrous for human civilization. Sustainable urban development requires realistic limits on any given region's natural carrying capacity, hard-core conservation and recycling of local finite natural resources, the promotion of limitless decentralized alternative energy sources, and a radical shift into environmental, economic and social development alternatives that promote healthy and advanced living arrangements and environments for future urban dwellers worldwide for the 21st century.
Recycling Solutions For The Environment and Our Future
According to the National Academy of Sciences, the Earth's surface temperature has risen by about 1 degree Fahrenheit in the past century, with accelerated warming during the past two decades. There is new and stronger evidence that most of the warming over the last 50 years is attributable to human activities. Human activities have altered the chemical composition of the atmosphere through the buildup of greenhouse gases – primarily carbon dioxide, methane, and nitrous oxide. The heat-trapping property of these gases is undisputed although uncertainties exist about exactly how earth's climate responds to them. In concern for the safety of the Earth we need to work on creating and using environmental recycling systems that even out the delicate balance between nature and human activities.Our Changing Atmosphere
Energy from the sun drives the earth's weather and climate, and heats the earth's surface; in turn, the earth radiates energy back into space. Atmospheric greenhouse gases (water vapor, carbon dioxide, and other gases) trap some of the outgoing energy, retaining heat somewhat like the glass panels of a greenhouse. Without this natural "greenhouse effect," temperatures would be much lower than they are now, and life as known today would not be possible. Instead, thanks to greenhouse gases, the earth's average temperature is a more hospitable 16.5°C. However, problems may arise when the atmospheric concentration of greenhouse gases increases.
Since the beginning of the industrial revolution, atmospheric concentrations of carbon dioxide have increased nearly 30%, methane concentrations have more than doubled, and nitrous oxide concentrations have risen by about 15%. These increases have enhanced the heat-trapping capability of the earth's atmosphere. Sulfate aerosols, a common air pollutant, cool the atmosphere by reflecting light back into space; however, sulfates are short-lived in the atmosphere and vary regionally.
Why are greenhouse gas concentrations
increasing? Scientists generally believe that the combustion of fossil
fuels and other human activities are the primary reason for the increased
concentration of carbon dioxide. Plant respiration and the decomposition
of organic matter release more than 10 times the CO 2 released by human
activities; but these releases have generally been in balance during
the centuries leading up to the industrial revolution with carbon dioxide
absorbed by terrestrial vegetation and the oceans.
Global mean surface temperatures have increased 0.278-0.556° C since the late 19th century. The 20th century's 10 warmest years all occurred in the last 15 years of the century. Of these, 1998 was the warmest year on record. The snow cover in the Northern Hemisphere and floating ice in the Arctic Ocean has decreased. Globally, sea level has risen 4-8 inches over the past century. Worldwide precipitation over land has increased by about one percent. The frequency of extreme rainfall events has increased throughout much of the United States. The need for recycling solutions for our environment have never been greater.
Increasing concentrations of greenhouse gases are likely to accelerate the rate of climate change. Scientists expect that the average global surface temperature could rise 0.56-2.5° C in the next fifty years, and 1.4-5.8° C in the next century, with significant regional variation. Evaporation will increase as the climate warms, which will increase average global precipitation. Soil moisture is likely to decline in many regions, and intense rainstorms are likely to become more frequent. Sea level is likely to rise two feet along most of the U.S. coast.
Calculations of climate change for specific areas are much less reliable than global ones, and it is unclear whether regional climate will become more variable.
Environmental Recycling Solutions
If the human race is to succeed in harmonizing with the planets ecosystem, large strives must be made towards developing and implementing environmentally sound recycling solutions. The ECOLUS™ pyrolysis recycling machine designed and patented by Kouei Industries is a viable closed loop alternative solution to the recycling of scrap tires and other polymer based products. Though there are many venues available for the reuse of scrap tires, most consume large quantities of energy in the effort to process the materials into their new, usable form. The recycling solution offered by KI minimizes the external energy needed to process the feedstock and thus is an advantageous means of processing polymer based waste and scrap into usable products. To sustain our current prosperity and even our existence on Earth, we must focus on efficient, environmentally sound solutions to our ever increasing product consumption and resulting wastes.
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