Recognizing that many developing countries and small island developing states that have contributed the least to climate change are most likely to suffer the consequences, the Paris Agreement contains a plan for developed countries – and others that are able to do so – to continue to provide financial resources to help developing countries reduce and increase their capacity to withstand climate change. The agreement builds on the financial commitments of the 2009 Copenhagen Accord, which aimed to increase public and private climate finance to developing countries to $100 billion per year by 2020. (To put it in perspective, in 2017 alone, global military spending amounted to about $1.7 trillion, more than a third of which came from the United States. The Copenhagen Pact also created the Green Climate Fund to mobilize transformation funding with targeted public dollars. The Paris agreement expected the world to set a higher annual target by 2025 to build on the $100 billion target by 2020 and create mechanisms to achieve this. To date, BHM estimates have been shown to be consistent with the relatively high social cost of carbon9, indicating that emission reductions should be severe. However, the impact on optimal policies was assessed only on the basis of pre-defined scenarios of warming and economic growth6,8,9,10. While such estimates are not without criticism, it is natural and necessary to compare them with climate change mitigation costs (mitigation costs, below) using an Integrated Assessment Model (IAM). IAm are the different dynamic interactions between the economy and the climate12,13. The NRDC is saddened to make the Global Climate Action Summit a success based on more ambitious commitments to the historic 2015 agreement and enhanced initiatives to reduce pollution. This special edition calls for contributions to the assessment of the total costs associated with the implementation of the obligations defined by the NdCs, which are an integral part of the Paris Agreement. In addition, the interest is also to assess the cost of achieving the temperature target of 2 degrees Celsius, both in the event of full participation in the agreement and partial participation, as illustrated by the withdrawal of the United States under the Trump administration. The Paris climate agreement aims to keep temperature rises well below 2 degrees Celsius.
This involves mitigation and prevention costs for climate damage. Here we show that the agreement is the economically optimal political path for the century, regardless of normative assumptions of inequality aversion and temporal preferences. To this end, we systematically integrate a cost-damage curve that replicates the observed ratio of temperature to economic growth in the DICE integrated assessment model.