Earth axis

[claymore]

would life on this planet have been much different than today if the earths axis was not tilted?

[Count-A-Strong]

The seasons would be different. You have to take into account the fact that the earths orbit is not circular and the northern hemisphere experiences summer when the earth is furthest from the sun. An Earth with a vertical axis would probably mean ccoler summers and milder winters (I think).

More effects:
http://wiki.answers.c...s_axis_was_not_tilted

[Count-A-Strong]

some more info here:
http://www.theweather...n.com/habyhints2/471/

[New Judge]

The predominant driver which accounts for changing seasons on earth is the tilt of its axis. Although its orbit around the Sun is not circular, the variation between the planet’s closest and farthest distance from the sun is about 2%. In fact the earth is nearest the Sun in early January but this difference in distance makes virtually no difference to the climate.

The seasons are caused mainly because as the earth progresses around the sun the angle that sunlight strikes the earth at any given latitude changes. To us the Sun appears higher or lower in the sky and it is this changing angle that causes our climate to be warmer or cooler throughout the year.

If the earth’s axis was perpendicular to its orbit around the Sun the seasonal differences would be far less pronounced (there may be a small seasonal effect due to the variation in distance mentioned above). Another manifestation would be that the length of the day at any given latitude would be identical throughout the year. The Sun would rise and set at the same time every day. (Once again it is the earth’s tilted axis which causes variation the length of the days).

All this means that life (or certainly the way life evolved) would probably have been quite different.

[ludwig]

Yes. Everything would be leaning slightly to the left.

[jake-the-peg]

Well I guess you actually knew that there wouldn't be any seasons but let's think about some of those effects.

Firstly temeperature ranges and daylight would be fixed, I guess that would mean that areas around the poles would never defrost meaning that the habitable part of the planet would be more restricted than it is today.

As for the plants - well they'd be much more like tropical ones, there wouldn't be deciduous plants and you'd probably not have any migratory animals and birds. We'd certainly not be eating the same crops

But the biggest change would be the weather. There are many seasonal weather effects like the trade winds in the Indian ocean that have played a huge part in our development.

I guess without the Earth's tilt the weather might be much more static than it is today not sure if that would be a good thing!

[rov1200]

Strange that even apart from evolution circumstances such as this benefit the human race enormously. Even a celestial designer would have got top marks for it!

[chakka35]

Cart before the horse, rov1200. We are here because the circumstances were favourable to us. No designer made them especially to suit flora and fauna that might or might not have evolved a long time in the future.

[Andyvon]

The growing season for many plants in temperate regions is governed by sensing the light of lengthening days. It's also the same for many animals who come out of hibernation when the days have warmed and lengthened. Seasons and tempreature variations also affect ocean and air currents as well as animals and bird migration.

I'm not sure if life itself would have been drastically different with no seasons on Earth, but behaviours most certainly would.