The oceans cover over 70% of our planet's surface. Their physical, chemical and
biological properties form the basis of the essential controls that facilitate life on
Earth. Current concerns such as global climate change, pollution of the world's
oceans, declining fish stocks, and the recovery of inorganic and organic chemicals
and pharmaceuticals from the oceans call for greater knowledge of this complex
medium. This volume brings together a number of experts in marine science and
technology to provide a wide-ranging examination of some issues of major
Greenhouse gases 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,
but we cannot rule out that some significant part of
these changes is also a reflection of natural variability.
Human-induced warming and associated sea level rises are
expected to continue through the 21st century.
Global warming is the rising average temperature of Earth's atmosphere and oceans since the late 19th century and its projected continuation. Since the early 20th century, Earth's average surface temperature has increased by about 0.8 °C, with about two thirds of the increase occurring since 1980. Warming of the climate system is unequivocal, and scientists are more than 90% certain that most of it is caused by increasing concentrations of greenhouse gases produced by human activities such as deforestation and the burning of fossil fuels.
Volcanic eruptions are among the Earth's most powerful and destructive forces. Imagine
hearing a volcano erupt thousands of miles away. Imagine looking through binoculars
and seeing the top of a mountain collapse. Imagine discovering an ancient Roman city
that had been buried in volcanic ash.
Volcanoes are also creative forces. The Earth's first oceans and atmosphere formed from
the gases given off by volcanoes. In turn, oceans and an atmosphere created the
environment that made life possible on our planet. Volcanoes have also shaped the
The burning of fossil fuels puts into the atmosphere carbon dioxide, which is
causing gradual global warming. This 'greenhouse effect' may by early next century have
increased average global temperatures enough to shift agricultural production areas, raise sea
levels to flood coastal cities, and disrupt national economies.