Global Environment and Water Resources & Food Production
Zenbei Uchijima
President
Miyazaki Municipal University
1. Preface
According to recent studies of Earth Planet Science, the Earth having the radius of 6,380 km, is said to have become the present size within 100 million years from 4.6 billion years ago. And lives were born in the primordial oceans about 4 billion years ago. Since then, the stream of lives has flown without ceasing, and evolved to the biosphere where various species inhabit as we see today.
The reason the lives have existed as long as for 4 billion years, despite the fact that extraordinary natural events, at times, caused massive extinction, should rest in the following basic conditions, that the Earth, where we live, has satisfied.
The temperature near its surface has kept between 0℃ and 40℃, which is the suitable range for lives of organisms.
A substantial amount of liquid water has existed on the Earth, and protected the global environment from the harmful solar ultraviolet rays.
On the other hand, all the species on the Earth, including the human beings, obtain their energy for living from the solar energy stored in dry matters that are produced by photosynthesis of chlorophytes.
Photosynthesis of chlorophytes is closely related to the solar energy incidence, temperature conditions, and water resources. With the forthcoming explosion of the world population, securing energy for lives of human beings, viz., food production will be the greatest problem in the near future. To solve this problem, there is a constraint of limited land resources, as well as issues of securing fresh water resources and its efficient utilization.
This article will, therefore, briefly discuss the issue of global water resources from the viewpoint of global envirnment and food production.
