According to the Stern Review, climate change could cost the world 20% of its GDP in damages. And also claims that taking steps to tackle climate change would only cost the world 1% of its GDP.
The IPCC released its 1st assessment report in 1990, concluding that temperatures had risen by 0.3-0.6°C in the last 100 years, and warned that humanity’s actions were contributing to the trend.
The fact that Climate Change is a real issue has been suggested by climate scientists for several decades. But when did people start to realise that something was wrong with our climate?