Answer:
the earth is tilted 28 degree
Explanation:
The main reason why we have seasons during the year is because the Earth is tilted 23.5 degrees on its axis. In it's orbit around the sun, when the Earth is tilted toward the sun it is summer in the Northern Hemisphere and when the Earth is tilted away from the sun it is winter in the Northern Hemisphere. In the Southern Hemisphere it would be the other way round. Since the Earth orbits the sun steadily, this pattern repeats itself every year.
Well, if the Earth was not tilted, the plane of the Earth's poles would always be perpendicular to the sun, and. The sun would always be just on the horizon 24 hours a day on every day at the poles. There will be no nights at all in the polar regions. Every day would be an "equinox" and throughout the Earth (except the polar regions) there will be a 12 hour "day" and a 12 hour "night" and the sun angle would be about the same every day. There would no longer be seasons as we know them now. The climate, i.e., temperature and the rainfall pattern would not vary much. It would always be hot in the equatorial region and cold at the polar egions. The same climate will last throughout the year, and year after year.
The changes in the oceans and atmosphere would result in tremendous and unpredictable changes in conditions on the earth's surface including shifts in the oceans' levels and changes in the location and extent tropical areas. The tropic of Cancer and tropic of Capricorn would be meaningless because there would be no more "solstices" - it would be an eternal "equinox" meaning the sun rises exactly due East, and sets exactly due West after passing over the equator, day after day, year after year.
There will be a profound effect on the migratory birds and animals. They will find no reason for migration as there are no more seasons. Imagine what may happen if all the bird migration stops! Presently, because of migration, the population of millions of migratory/non migratory creatures are in balance; but if there were no migration, their populations may increase uncontrollably, causing a major zoological imbalance. (Imagine what will happen in East Africa. Every year, blue wildebeest have a long-distance migration looking for greener pastures, coinciding with the annual pattern of rainfall and grass growth. With no seasons there would be no need to migrate.)
And then, an Earth without it's tilt would be divided into climate "bands" that would get progressively colder as we moved away from the equator in both directions. People may not be able to survive the continuous winter of the higher latitudes - like Scandinavia, Greenland, Siberia, Mongolia etc. - and so the population of the Earth would probably concentrate in the midsection tropical/equatorial regions of the planet. Needless to mention, there would be chaos! We may not be able to feed ourselves anymore, because:
The tropical zone would be humid and so, continuous rainfall would quickly erode the soil and drain away the top-soil and the nutrients, making the land useless for agriculture.
We would be plagued by diseases, the pathogens of which thrive in warm, humid environments. You must be aware that cold climate protects much of the world's population from disease carrying tropical insects which account for diseases not only in humans, but also crops and livestock. The tropics is home to MALARIA, EBOLA, and HIV. We just cannot imagine the devastation caused by deaths due to diseases coupled with hunger. As I write this, the world population is 7.32 billion and the annual increase is estimated at 1.10%. Imagine the lot living within some 40° north and south of the equator!
Let's not forget, as our numbers increase, the numbers of other inhabitants of the planet has steadily decreased; many species have even gone extinct due to loss of habitat, pollution, and global warming. With the human population concentrated in the tropical regions, there is bound to be overfishing and over-hunting. Scientists believe that with the current rate of extinction, we will experience a mass extinction in which 75 percent of the planet's species will be extinct within short period of time, like 300 years or so. On an Earth without it's tilt, it would be a lot sooner.
So whatsay, we let the present tilt of the Earth continue until further notice?
Add: Eclipses will become common. Every new-moon will be a solar eclipse and every full moon a lunar eclipse. Some of the solar eclipses would be total, while others would be annular, depending on the how far the moon is from the earth.