German Institute for Economic Research (DIW) reported that if nothing is done to halve GHG, economic damages could amount to US$20 trillion by 2100, or 6-8% of global economic output. The study goes on to say that if immediate action were to be taken in climate change policies to limit temperature increase to 2 degrees by spending $3 trillion per year on climate protection, it could halve these damages, avoiding around $12 trillion incurred costs. If protection does not begin until 2025, it would be impossible to limit warming to 2 degrees by 2100, therefore the later climate protection starts, the more expensive it will become.
Source: Climate Change – the Costs of Inaction (PDF) – Frank Ackerman and Elizabeth Stanton – Global Development and Environment Institute – Tufts University, MA, USA
Date: 11 October 2006