Climate change: the story so far

The concentration of CO2 in our atmosphere has increased by 40 per cent; from approximately 280 parts ppm in the 19th century to 400 ppm measured in May of this year.4 Since the year 1750, humans have added approximately 1.3 trillion tonnes of CO2 to the atmosphere as a result of burning fossil fuels, cement production and gas flaring,5 and a further 0.7 trillion tonnes from land use changes such as deforestation6 (Figure 2). Background