Solution to Global Problems: Countries of our Planet Create a Federation to Address Particularly Global Issues?
The concept here is that such a political structure would more effectively specifically address areas of global concerns as supported by funding from federation members. As such, the Federation and our world would have a single voice to address global matters, whether it be global warming, pandemics, threats from outer space from collisions, etc.
Member nations would submit representatives who would elect a leader.
The concept resembles the United Nations, but a more powerful entity with a singular focus on short and long term global matters. The United Nations itself would be relieved of such responsibilities and institutions such as the World Health Organization could be folded into the organization.
Given the half-hearted attempt on addressing global warming seen to date, for example, there is a necessity for such an entity and out of necessity comes invention.
Some historical background per Wikipedia, to quote:
World government or global government, sometimes called one-worldism or cosmocracy, is the concept of a single political authority for all humanity. It generally entails some form of government through a single state or polity with jurisdiction over the entire world. Such a government could come into existence through violent and compulsory world domination, or through peaceful and voluntary supranational union. World government is conceived in a variety of forms, which reflects its wide array of proponents, ranging from ancient kings and Enlightenment philosophers, to religious utopians and secular humanists.
Global government has been proposed and even attempted since antiquity. Over the last few centuries, gradual developments in international law, international relations, and international organizations, along with concurrent trends such as globalization and industrialiation, have led to greater interest and discussion about world government by both scholars and the general public. However, there has never been an executive, legislature, judiciary, military, or constitution with global jurisdiction.
Where, I would argue, the qualifying comments in the last sentence will be mitigated by the particular global primary focus of the government.