It is possible Why so many people have a problem imagining a governing system that is in charge of the entire planet is because they are trying to imagine a new government based upon the existing structure of the old one. For example, in the United States, we have not a democracy but a democratic republic. We don't make decisions for ourselves; rather, we vote for people to make decisions for us. This was an effective system when the United States was first conceived. The population was so dispersed, and communication so difficult, that the most effective form of government was one that localized power to a select few. Fast forward to today. We live in a world that becomes more and more connected every day. Communication is almost instantaneous, and everyone can (with access the proper resources) be "plugged in." Why don't we create a new form of government? One that the citizens vote for representatives, but is also fully transparent. The citizens would have the opportunity to go online to a central "hub" and vote on issues directly. They would have the ability to navigate through local and global issues, and would be able to overturn any political action taken by the representatives by a majority vote. This would help to prevent the corruption that can run so rampant through the systems we currently have.
A global government is possible; and if we want to progress as a species, it is necessary.Also It can work There are 196 countries in the world. That means a parliament/senate if you wish with 196 members. A lot of minds and ideas to make the world a better place. All that remains is to get rid of greed and selfishness. Banks, big oil and pharma companies need to be put in their place.