Maybe you’ve been lucky enough to see a coral reef with your own eyes. Maybe the first thing that comes to mind is the movie Finding Nemo. But almost everyone has some kind of image in mind and remembers the joy and amazement of seeing the colorful undersea chaos. So for almost everyone, it will also mean a very personal loss if these natural wonders soon cease to exist.
The cause of their disappearance is the climate crisis. If the current trend continues, global heating will rise to 1.5°C before 2040, and 70 to 90 percent of coral reefs will die. If global heating reaches 2°C, there will be virtually no coral reefs left: 98 to 99 percent will not be able to survive at those temperatures. 
But the supposedly small difference between 1.5 and 2°C also has dramatic effects in many other areas. Can you, for example, imagine the North Pole completely without snow and ice? When global heating reaches 1.5°C, that’s something we will see every 40 years, at 2°C even every three to five years. 
And it’s not just the nice things getting less, it’s also the bad things getting worse. A storm surge that would have been expected every 500 years in Cuxhaven on the North Sea would occur every 100 years if the earth were to heat up by 1.5°C, and even every 33 years if it were to heat up by 2°C. In other words: two or three times in your lifetime. And a heat wave like the one in 2003 which caused 70,000 deaths in Europe could occur every year in the future. That’s one more thing that will be felt by everyone in Europe.
Droughts and famines will have an impact on the global political situation and subsequently on every single individual. In Africa, sub-Saharan Africa, Southeast Asia, and Latin America, fruit and vegetable yields will decline sharply as a result of global warming. Also, especially in arid regions, water supply problems are likely to increase critically at 1.5°, and twice as much at 2°C. 
Another factor that should not be underestimated is the psychological strain in the here and now. Our children in particular are growing up with the depressing prospect that so-called tipping points might be exceeded in their lifetime. As a result, global heating would become a vicious circle. The permanently frozen soils in the north of our planet, for example, could thaw and release more and more methane, a powerful greenhouse gas.  The consequences, scientists warn, would be disastrous: “Life on Earth can recover from drastic climate change by evolving into new species and creating new ecosystems … Humans cannot.” 
But there is also a silver lining. Indeed, the claim that it would be too expensive to save the climate has finally been disproved. Renewable energies are now the cheapest form of electricity generation almost everywhere in the world.  So there’s really no reason to keep burning fossil fuels. We could build a new energy infrastructure based on fossil-free electricity, create a lot of jobs in Germany and save money in the process. If we don’t do this, however, the forecasts of climate scientists will soon become reality, and we will experience first-hand the life-changing impact that half a degree Celsius can have.