Although there are countless exoplanets deep in the universe, and perhaps among these exoplanets there are billions of planets suitable for human habitation, most exoplanets are very far away from our earth and will not be able to survive for a long time. None of us can reach the

Although there are countless exoplanets deep in the universe, and perhaps there are billions of planets suitable for our human habitation among these exoplanets, most exoplanets are very far away from our earth. We won't be able to reach these exoplanets for a long time, so the earth is our only home for now. As the only home for us humans, the quality of the earth's environment will affect our human development and even survival. Just imagine, if the earth's environment deteriorates to the point where it becomes uninhabitable in the future, then our human civilization will be annihilated. Therefore, we all hope that the so-called "doomsday" will come. However, the current situation of the earth is not optimistic. One of the problems is climate warming.

The worst fear of extreme high temperatures is just the beginning

Over the years, we have often talked about the issue of climate warming. In the past 10 years, we have seen the "hottest summer" almost every summer, that is, the average temperature in summer is higher than in the past It will be higher in summer for quite some time. In May of this year, World Meteorological OrganizationSecretary-General Petiri Taalas once said that the past 7 years have been the hottest 7 years in history, and we will see the next "hottest year on record." It's just a matter of time. As climate warming continues, the average temperature of the earth will continue to rise, and future summers may become hotter and hotter. It is very possible that the "hottest year on record" will occur again.

Perhaps some friends think this may be alarmist and think that the so-called climate warming is a scam. After so many years of shouting, is the earth really getting warmer? The process of climate warming is long and slow. It does not rise by a few degrees or dozens of degrees all at once. We cannot feel the subtle changes in temperature every year. But from the data recorded by scientists, we can indeed see that the average temperature of the earth is really rising. According to the "State of the Global Climate in 2020" released by the World Meteorological Organization, the average temperature of the earth has now increased by about 1.2°C compared with the temperature level before the industrial revolution.

Scientists worry that the current extreme high temperatures may be just the beginning, because the earth's climate warming trend has not yet been alleviated. In the " Paris Agreement " adopted in 2015, all countries have formulated detailed plans for emission reductions. Some experts predict that even if the 194 parties to the "Paris Agreement" have achieved their respective reduction plans without any compromise, According to climate change plans, global temperatures are still likely to rise by 2.7°C within this century. That is, the future may be hotter than now. Scientists worry that if the earth really warms up by 2.7°C, some disasters may inevitably occur.

Things that threaten 5 billion people may happen

According to the predictions of some experts, under ideal conditions, that is, when all 194 parties to the Paris Agreement have completed their emission reduction tasks as agreed, the earth may be If the temperature rises by 2.7°C, if some countries fail to complete their emission reduction tasks as agreed, the problems facing the earth may become more severe and the earth may be more dangerous.

According to a new study published in "Communications - Earth and Environment", by the end of this century, the earth's temperature will rise by 3°C. By then, more than 5 billion people every year will be exposed to dangerously high temperatures most of the time. in humid environment. In the study, Lucas Zeppetello of Harvard University in the United States and his colleagues simulated the future emissions of greenhouse gas based on population growth, economic growth and other data. The results found that by 2100, the average temperature of the earth may rise by 2.1℃-4.3℃. The most likely scenario is for the earth to rise by 3°C.

If, as simulated by researchers at Harvard University, the earth heats up by about 3°C ​​by the end of this century, then by 2050, tropical and subtropical regions will experience dangerous heat for a quarter to half of the year. Weather, we will experience dangerously hot weather most of the time by the end of the century.Combined with population growth, it is estimated that by 2100, 5.3 billion people in India, sub-Saharan Africa and the Arabian Peninsula may be exposed to extremely dangerous high temperatures every year.

What should humans do in the future?

Although we don’t know how accurate the research of these researchers is, after all, this will happen in the next few decades. There are many factors that affect the future temperature of the earth. In addition to the issue of climate warming, there is also solar activity. and other factors will also affect the earth, but if the earth's climate warming is allowed to continue, the earth's temperature will continue to rise in the future. Once the earth's temperature reaches a certain critical point in the future, the threat to us humans may be greater. Therefore, what should humans do in the future is a question worth thinking about.

If the universe was not that big, the distance between exoplanets and our earth was not that far, and we would immigrate to habitable planets before the earth's environment deteriorated, the threat to human civilization would not be as great as imagined. However, the Voyager 1 and Voyager 2 probes have told us with actual actions that the universe is too big. These two probes have been flying for more than 40 years and have not even seen the edge of the solar system. Scientists believe that they It still takes tens of thousands of years of flight to reach the vicinity of the next star system . Such a long time is obviously unacceptable to us humans. Therefore, when we are looking for a habitable planet at this stage, we also need to focus on protecting the earth's environment.

The problem of climate warming is ultimately a problem of greenhouse gas emissions. As a large amount of greenhouse gases are discharged into the atmosphere, the earth's greenhouse effect will become more and more obvious. These greenhouse gases will have a "heat preservation" effect, thus Let the earth's temperature continue to rise. Therefore, if we want to alleviate the trend of climate warming, we can start by reducing emissions. In the Paris Agreement, all countries have formulated detailed plans for emission reductions. If everyone follows the agreement to achieve emission reductions, it will indeed be able to alleviate the trend of climate warming to a large extent.

Of course, just reducing emissions cannot completely alleviate climate warming. Even if greenhouse gases are no longer emitted, the temperature of the earth will not drop directly. Because after so many years of development, there are already a large amount of greenhouse gases in the atmosphere, and these greenhouse gases will continue to affect the earth's temperature. Therefore, when we reduce emissions, we also need to take measures to absorb greenhouse gases already in the atmosphere. For example, the afforestation we have been promoting over the years is an effective method. Green forests can absorb carbon dioxide from the atmosphere. This can also alleviate the trend of climate warming.