Why do leaves turn autumn colours?

Autum colours are caused by chemical changes that occur within the leaves. Every green leaf is filled with microscopic chlorophyll bodies that give it the green colour. These chlorophyll bodies (called chloroplasts) are tiny food-production factories that make food from water, oxygen, and carbon dioxide, using sunlight for power (energy.) The cool weather that accompanies the approach of autumn causes these processes to slow down and eventually to cease completely. When the tiny factories shut down for the winter the chlorophyll breaks up into other substances, and the food is stored in the body of the tree. After this happens the only chemical substances left in the leaf are a watery substance, some oil droplets, and some yellow bodies that give the leaf its yellow colour. Sometimes, however, some of the food becomes trapped in the leaf. This allows further chemical changes, which produce various shades of red.

At the point where the leaf is attached to the tree a special layer of cells grows, sealing off the leaf from the branch. This separates the leaf from the tree and allows it to be blown off by the next breeze.

So ends the life of every single deciduous leaf. It buds in the spring, matures, and does its job through the summer, then bids farewell to the tree in autumn. But even in death a leaf gives to the world a demonstration of beauty and stimulates hope. Autumn colours somehow help to take the edge of winter’s chill arrival.

Without the hope of resurrection this world would appear as the approach of an eternal winter. It would appear that there is no continuity between this life and the next. Fortunately, the gulf has been bridged by God’s creative acts. Paul constantly works from Christ’s resurrection to our own.  So, there is hope!

“But in fact, Christ has been raised from the dead. He is the first of a great harvest of all who have died. So you see, just as death came into the world through a man, now the resurrection from the dead has begun through another man. Just as everyone dies because we all belong to Adam, everyone who belongs to Christ will be given new life. But there is an order to this resurrection: Christ was raised as the first of the harvest; then all who belong to Christ will be raised when he comes back. After that the end will come, … And the last enemy to be destroyed is death.”  Corinthians 15:20-26 NLT

After Noah’s flood, God gave the seasons as a reassurance to humanity that He would not again change the regularity of earth’s year; “I will never again curse the ground because of the human race, even though everything they think or imagine is bent toward evil from childhood. I will never again destroy all living things.  As long as the earth remains, there will be planting and harvest, cold and heat, summer and winter, day and night.” Genesis 8:21-22