Answer:
public good.
Step-by-step explanation:
Global Public Goods can be defined as those goods that are consumed across global borders. People across borders share the benefits of global public goods. For instance, ozone layer, sunlight, etc are examples of global public goods.
In the given case, the cost of reducing carbon emissions will be counted under public goods. The emission of carbon dioxide and greenhouse gas comes under the global public goods.
Therefore, the correct answer is public goods.