In 2018, a report by the Intergovernmental Panel on Climate Change (IPCC) warned humanity needs to cut its carbon dioxide emissions in half by 2030, to avoid global warming of 1.5 degrees Celsius above the levels seen before the industrial revolution.
The report states we have about 12 years before fixing the damages of climate change becomes expensive and tough. We can all still live in a world with climate change, but it will require a lot of work, and many lives and livelihood are going to be threatened by the change. It is complicated because in this century, we are facing many problems all at the same time, and we are depended on each other than ever before.
Most humans depend on global transport, logistics systems, and payment systems to get food. In turn, fuel, electricity, communications and other things are required in return for the exchange to work properly. All these systems are connected to each other, so if one starts failing, it may cause a domino effect and it could crash other systems too, it could result in massive shortages and conflicts.
It is difficult to calculate the exact risk of this happening since it has never happened before. We do know that climate change puts the whole world under pressure, making the risk of these systems to collapse.
Geoengineering is set to reduce the impact of climate change, and it might work. But if disaster strikes and those operations stop, the effects of climate change can return quickly. The most reasonable thing to do is to work on making our systems more resilient. This means that it needs more local energy production, there should be more work on reducing climate change, in creating better back up systems and being more willing to pay extra for safety.
There are other threats that humanity is facing, aside from climate change. There are natural hazards such as tsunamis, earthquakes, volcanoes, and hurricanes and they can all be disastrous as they pose a comparatively small threat to the survival of the human race. Hazards that are big enough to cause an entire species to go extinct are very rare.
There are also pandemics that could threaten humanity, as in 1918 a flue killed tens of millions of people all over the world. New influenza viruses are popping up all the time, and there is an expected pandemic to happen at least once in every 100 years. The good news is, over the past century, humans have become better at medicine. It is not likely that a pandemic can cause the extinction of the human race but a bad pandemic might still wreck our society.
Bioweapons is also an issue since it uses viruses, bacteria or fungi to harm humans or agriculture. Fortunately, they have been rarely used in war, but they might become more dangerous in the near future because of the advances in biotechnology.
Right now, the biggest risk to humanity is nuclear weapons. The risk varies, depending on the tensions between countries and the competence of the people who are handling early warning systems.
We can't give a probability of a world-ending disaster, but we do know that there is a big enough risk of disasters happening in our lifetimes that we should work hard to fix, whether by making sure that the governments and the AI stay safe and sane, building backup system and plans, replacing fossil fuels, decentralizing key systems and more. These things are worthwhile, even if the risk is rarely to happen. We only have one world to live in, and the future of it is vast.
