A report in May 2011 on the Global Peace Index, found that if the world had been 25% more peaceful in the previous year, the global economy would have had an additional $2 trillion. This amount would have covered 2% of the GDP per year required to avoid the worst effects of global warming, cover all costs to achieve the Millennium Development Goals, cancel the public debt held by Greece, Ireland and Portugal, and cover the one-time rebuilding costs for the 2011 Tōhoku earthquake and tsunami.