Cumulative mitigation costs (green curve) and climatic damage (black curve) depending on the level of global warming give the total cost of the climate (red curve). Today`s warming mitigation costs vary and are close to zero in the event of effrimized warming. Damage is zero for zero warming and increases with temperature. The characteristic slope of the reduction curve implies that beyond a certain level of damage, the economically optimal temperature (which minimizes the total cost) becomes insensitive to a further increase in damage. For example, the increase (dotted in black) or decreasing (black dot) does not significantly alter the level of damage by half of the initial level of damage to economically optimal warming (grey). Another key difference between the Paris Agreement and the Kyoto Protocol is its scope. While the Kyoto Protocol distinguishes between Schedule 1 countries and those not annexed to Schedule 1, this branch is scrambled in the Paris Agreement, as all parties must submit emission reduction plans.  While the Paris Agreement continues to emphasize the principle of „common but differentiated responsibility and respective capabilities“ – the recognition that different nations have different capacities and duties to combat climate change – it does not offer a specific separation between developed and developing countries.  It therefore appears that negotiators will have to continue to address this issue in future rounds of negotiations, although the debate on differentiation could take on a new dynamic.  The Paris Agreement officially entered into force on 4 November 2016.
Other countries remained parties to the agreement following their national approval procedures. To date, 195 contracting parties have signed the agreement and have ratified 189. For more information on the Paris Agreement and ratification status, click here. „This is certainly a blow to the Paris agreement,“ said Carlos Fuller of Belize, the negotiator for the Alliance of Small Island States in the UN talks. On the corporate side, shareholders in major fossil fuel industries are increasingly in a hurry to meet the climate challenge. At the 2015 Paris conference, at which the agreement was negotiated, developed countries reaffirmed their commitment to mobilize $100 billion a year to finance climate by 2020 and agreed to continue mobilizing $100 billion a year by 2025.  The commitment refers to the existing plan to allocate $100 billion per year to developing countries for climate change adaptation and climate change mitigation.  The formal withdrawal has also allowed climate diplomats to reopen old wounds. 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.