This article:
http://www.newscientist.com/article/dn11638
gives one view of the figures. Human emissions amount to about 26 gigatons out of a total of 796 � about 3.2%. As I said, although the quoted figures may vary slightly between reports, it is in the region of 4%.
I have to say that having read the entire article, it seems the author has decided on the answer he wishes to portray and manipulates the evidence to reach his conclusion. I think this particularly when I am asked to believe that the 97% or so of �natural� emissions manage to remain precisely in balance, but the three or four per cent produced by humans cannot be dealt with by natural means and so is accumulating to alarming levels.
However, the argument can go on forever (or at least until we all die, which will almost certainly be due to causes unrelated to climate change).
My main gripe with the climate change lobby is that, regardless of whether the problem is real or perceived, I am being asked to make changes to my lifestyle which will make absolutely no difference whatsoever. Meanwhile the hypocritical politicians who tell me I am responsible for all this trouble make no adjustments at all. Whilst I am sitting under my dim �eco friendly� lightbulb, with the heating turned off, the Prime Minister travels 20,000 miles touring to meet world leaders who he was due to see in London the following week; the president of the USA flies on a tour of Europe with up to 500 staff; and government buildings and the ludicrous �European Climate Exchange� in London are illuminated 24/7.
Meantime, the US (22%), China (18%), Russia and India (5% each) produce over half of all the �4%� with no indication that they will do anything about it at all. But if I switch to useless lightbulbs it will drastically cut the 2.2% produced by the UK