I don't know where SP of Narborough gets his information about volcanoes negating every effort of mankind to control CO2 emissions. Like too many who enter the climate change debate, he doesn't identify his sources. The Met Office has the most extensive dataset in the world, and makes it fully available to the public. Its conclusion is that "We know from global temperature records www.metoffice.gov.uk/climate change/guide/science/explained/temp-records that the Earth has warmed by about 0.75 degrees Centigrade in the last century. In the last four decades the Earth has warmed at an accelerated rate." www.metoffice.gov.uk/climate-change/guide/how

You can dig in to the data and come to your own conclusions: The Met Office's own 'flagship dataset', the only one in the world going back to the 1850s: www.metoffice.gov.uk/hadobs/hadcrut3/diagnostics/comparison.html while the US Department of Commerce's NOAA data goes back to 1880: www.ncdc.noaa.gov/cmb-faq/anomalies.php and NASA's GISS dataset also goes back to 1880: www.data.giss.nasa.gov/gistemp/graphs/

All of these data sources show a marked increase in global temperatures over the last century, particularly in the last four decades. As to the causes: there is good science linking man-made emissions to the level of CO2 in the atmosphere. And the mechanism of the greenhouse effect is basic science established over a hundred years ago and tested many times. Of the causes that SP mentions: Volcanoes have significant short-term impact but they average out over time. Solar and cosmic cycles haven't been shown to have any great effect on solar energy output. And the increase in bushfires is more likely to be an effect of global warming than a cause.