Tristanc, average temperatures have increased by ~1'C since the 1830s to about 14'C. That's how the maths demonstrates an increase on average of ~7%.
Although people wont die from current CO2 levels, the impact of particulates and toxic gases such as nitrous oxides is a huge issue for people whose lungs are less than 100% - as a visit to any nursing home will demonstrate! So too with the greater extremes in temperatures - many people cannot tolerate temperatures beyond 40'C.
