Geo Ghost wrote:Hoping this eruption comes to and end soon. Caused enough trouble last time and it's not exactly doing the environment any good.
Reallying hoping no one dares say "least the planes won't be producing as much CO2" - Volcanic eruptions don't just spew out a bit of Carbon Dioxide. They also give out much more harmful gases and such if I remember correctly?
Actually you'd be surprised. Big volcanic eruptions tend to actually cause global COOLING rather than warming! The effect is that Sulphuric Acid particles are so tiny that they are efficient backscatters (reflectors) of incoming solar radiation, which means less heat reaches the Earth's surface, meaning the Earth cools down. Several famines in the last 500 years have been attributed to large volcanic eruptions.
Edit: Didn't read michael's post, which pretty much says the same thing.
But yes, you're correct in that the Volcanoes release vast amounts of CO2, and I believe that about 60% of all CO2 emissions (might be slightly more) are natural, from sources like volcanoes and decomposing etc. Now you suddenly breathe a sigh of relief that we're not the only contributor, but then remember that if the natural CO2 has been in equilibrium for hundreds of millions of years, then our additional 40% is going to have huge adverse affects, and already is.
I doubt anyone's interested but I've pasted 3 paragraphs from an essay I did 3 months ago which explains Volcanic Global Cooling in detail:
Modern consensus regards sulphur dioxide and its derivative, sulphuric acid as far more important in explaining climate change following an eruption. For example, 20 terragrams of sulphur dioxide were released from the Mt Pinatubo eruption, which is converted into sulphuric acid in the atmosphere to become the dominant aerosol (Bell & Walker, 1992). Alongside ground material and colour, albedo is heavily influenced by the concentration of aerosols in the atmosphere, which are efficient backscatters but only weak absorbers. By being distributed globally, the albedo of the Earth including its atmosphere can be significantly increased, resulting in a cooling. Albedo data from the Earth Radiation Budget Experiment found that albedo increased in the following 3 months after the Mt Pinatubo eruption relative to the 5 year mean, and that global albedo in August 1991, 3 months after the eruption was 0.250, more than 5 standard deviations greater than the 5 year mean of 0.236 (McCormick, Thomason, & Trepte, 1995). Sulphuric acid aerosols remain in the atmosphere for between 1 and 5 years, affecting climate change for some time after the eruption itself.
Temperature falls have therefore often been attributed to major eruptions. The Microwave Sounding Unit satellite detected a decrease of 0.7°C in the wake of Mt Pinatubo’s eruption, accounting for the increase in temperatures due to ENSO that year. Likewise, the eruption of Mt Tambora, a comparable eruption in 1815, lowered the temperature by 0.4°-0.7°. The eruption of Krakatau in 1883, another event known to have released vast quantities of sulphur dioxide into the atmosphere, reduced temperatures by 0.3°C (McCormick, Thomason, & Trepte, 1995). Over the last 1000 years, 22-23% of temperature variations before the anthropogenic increase in carbon dioxide has been attributed to volcanism. During the Little Ice Age between 1400 and 1850, 41-49% of coolings have been attributed. Nonetheless, an increase in aerosols also has the potential to warm the Earth. Particles greater than 2µm in radius result in warming rather than cooling of the earth as outgoing long-wave radiation is reflected back towards Earth, as per the greenhouse effect (McCormick, Thomason, & Trepte, 1995).
By using proxy data from ice cores, we can measure the level of sulphuric acid in the atmosphere throughout recent history. The existence of ice core tephra, a relatively rare volcanic glass, is evidence of eruptions. Acidity levels may also be measured to determine the amount of sulphuric acid washed out of the atmosphere in specific years. The GISP2 ice core, stretching back 110ka documents major events including Toba (73ka), which corresponds with the beginning of marine oxygen isotope stage 4. The data shows a marked increase in volcanic activity in the last 600 years in comparison with the previous 1500 years, matching with other proxy data indicating overall cooling in the Northern Hemisphere. Dendrochronological records for the past few centuries show low tree-ring densities and thus cooler years corresponding with large eruptions. Likewise, the 1920s-1950s was a period of marked increase in temperatures, corresponding with distinct lack of volcanic activity (Bell & Walker, 1992). Sudden large releases of methane in history have also been prompted as an explanation for the sharp brief warming at the end of the Paleogene, although with a half-life of 10 years, the effects of such a large greenhouse gas injection into the atmosphere would be confined to a much shorter period of time. It is very unlikely that volcanic forcing would be the main determinate of climate change.
