As mentioned above, the data that NASA Just released looked back several thousand years across thousands of points across the globe and has determined that the earth has actually on average been cooling down. I know that's hard to think of with the summer we are having, it's so easy to see an area running hotter than normal and try to mentally extrapolate a long term trend from that observation. This variation is one that is due to a significant El Niño pattern in the pacific ocean and these patters (El Niño and La Nina) are due to the subsurface oceanic currents and the geothermal activity on the ocean floor, not mankind.
Let's take just a moment to talk about the CO2 piece of the puzzle.
First let's look at the basics, according to JPL and NASA, currently man made C02 accounts for only about 7% of the total C02 generated. Most when they here this say 'no way' it must be higher...it's not. Every living organism animal or plant on the entire planet emits C02 when living and far more as it decomposes after death. Every leaf, blade of grass or any bug or animal when it dies emits C02, every living thing when it exhales emits CO2. For the first time in history we are cultivating huge quantities livestock and vast areas of cultivated land and have to feed our populations altered the balance to suit our days to day needs.
Next lets look at the C02 puzzle a bit
The concentration of CO2 in the atmosphere is about 0.035% by volume and just about 5000 years ago that level has been determined to be about 0.028%. Overall this is an increase in these concentrations and certainly a combination of factors play a part including the burning of various fossil and plant based materials. All in all though it's not that big of an increase and larger swings have been witnessed over the past 50,000 years due to volcanic activity and the cyclical nature of the past 3 ice ages.
Overall the numbers we are seeing now are higher than 3000 years ago and the question is how much CO2 can the earths natural systems sequester, eithier through plant based photosynthesis, the oceanic absorption or as simple precipitate.
Of all of the C02 generated naturally or man made, about two thirds of it is absorbed by the oceans, but as we live in a living 'system', a change in one area, man made or not will have consequences in another area. Currently the oceanic long term absorption of CO2 can best be expressed in the following equation:
CaCO3 + CO2 + H2O ⇌ Ca2+ + 2 HCO3−
Which is due to the ionic exchange within all of the oceans with the rocks and sands which are rich in calcium. This will provide for the mechanism to absorb and sequester CO2 but over time will result in an increase in the acidity of the ocean.
Polly volcanos should never be treated as just particles that will settle soon, that's the least of the problem with them, they emit absolutely huge quantities of not only CO2, but also mind boggling quantities of the stronger greenhouse gas sulphur dioxide, which persist far longer than CO2 and retains far more heat as a suspended gas in the atmospheric column.
In a recent United states Geological Survey (USGS) study an estimate was made that just volcanos alone emit 200 million tons of CO2 annually, not to mention the 310 million tons of sulphur dioxide that is emmited annually by geothermal sources.
http://hvo.wr.usgs.gov/volcanowatch/arc ... 02_15.html
At the end of the day Polly we live in the middle of mostly self correcting complex system that is influenced but many factors, including human factors, the question needs to be can we do better? What has been happening unfortunately is that much of the science has been mitigated by politics and by using fear we are trying to manipulate opinions. The discussion here has to be about just the science and the place we have on this planet....for at the end of the next century the politics will be forgotten, but our grandchildren will need to live with our decisions, for better or worse.Carbon dioxide is released when magma rises from the depths of the Earth on its way to the surface. Our studies here at Kilauea show that the eruption discharges between 8,000 and 30,000 metric tonnes of CO2 into the atmosphere each day. Actively erupting volcanoes release much more CO2 than sleeping ones do.
Gas studies at volcanoes worldwide have helped volcanologists tally up a global volcanic CO2 budget in the same way that nations around the globe have cooperated to determine how much CO2 is released by human activity through the burning of fossil fuels. Our studies show that globally, volcanoes on land and under the sea release a total of about 200 million tonnes of CO2 annually.
Personally I do not believe we are in the dire place many of the politicians try to place us, but we do need to pay attention to our actions and for many many reasons address our energy needs with a more balanced scientific approach.