There would be no seasons in the world if the earth's axis was vertical. There will be no heat or summer season, which would make life impossible on Earth latitudes making the planet significantly colder. Every day would be like what it currently is on the equinox since every location on Earth would have about a 12 hour sunlight days and the noon sun angle would be about the same every day. There would no longer be season as we know them. The temperature and precipitation pattern would not very much. But if Earth's axis tilted to 90 degrees, extreme seasons would cause intense climate change on every continent. During the summer, the Northern Hemisphere would experience nearly 24 hours of sunlight for months, which could melt ice caps, raise sea levels, and flood coastal cities.