4 Jan 07
I'm very scared about climate changing (i've done an interesting discussion too about that!). I hope we could still live on earth in the near future. In Italy climate is changing fast...and seasons are not the same...even climate experts says that a global weather change changed Italy's wheater :(. They said that now sudden phenomena, like rain, whirlwinds and lightnings are to be expected more and more in the future. I'm trying to spend less energy, only the energy I need (so I try to burn less fuel and keep air clean). I try to recycle all materials I can. I try to consume less water and paper. This is all I can do in my own
4 Jan 07
Global warming is the observed increase in the average temperature of the Earth's atmosphere and oceans in recent decades. The Earth's average near-surface atmospheric temperature rose 0.6 ± 0.2 ° Celsius (1.1 ± 0.4 ° Fahrenheit) in the 20th century. "In the light of new evidence and taking into account the remaining uncertainties, most of the observed warming over the last 50 years is likely to have been due to the increase in greenhouse gas concentrations". The largest contributing source of greenhouse gas is the burning of fossil fuels. Greenhouse gases are gases that contribute to the greenhouse effect. This effect was first described by Joseph Fourier in 1824, and was first investigated quantitatively in 1896 by the Swedish chemist Svante Arrhenius. An increase in global temperatures is expected to cause other changes, such as a rising sea level due to thermal expansion of the ocean in addition to melting of land ice. Changes are also expected in the amount and pattern of precipitation. The total annual power of hurricanes has increased markedly since the mid-1970's because their average intensity and duration have increased (in addition, there has been a high correlation of hurricane power with tropical sea-surface temperature). Changes in temperature and precipitation patterns may also increase the frequency, duration, and intensity of other extreme weather events, such as floods, droughts, heat waves, and tornadoes. Other consequences may include higher or lower agricultural yields, glacial retreat, reduced summer stream flows, species extinctions and increases in the ranges of disease vectors. Although warming is expected to affect the number and magnitude of these events, it is difficult to connect specific events to global warming. Although most studies focus on the period up to 2100, warming (and sea level rise due to thermal expansion) is expected to continue past then, since CO2 has an estimated atmospheric lifetime of 50 to 200 years. World net carbon-emission rates would need to be reduced approximately 60%–80% by 2050 to prevent global temperatures from rising more than 1°C above present. A 1°C rise would likely raise sea levels by no more than approximately 5 meters (16 feet) over the next 200 to 2000 years, whereas a 3°C rise would likely raise sea levels by 25 ± 10 meters (82 ± 33 feet) Only a small minority of climate scientists disagree that humanity's actions have played a major role in recent warming. There is more significant uncertainty regarding how much climate change should be expected in the future. There is a hotly contested political and public debate regarding whether anything should be done, and what could be done cost-effectively to reduce or reverse future warming or to deal with the expected consequences. Options include renewable energy, energy conservation, carbon offsets, voluntary population stabilization, and carbon capture and storage.