It was nonexistent before there was significant oxygen in the atmosphere.
After the Great Oxidation Event, we developed our ozone layer, complete with annual ozone "holes" at each pole.
We have evidence of sporadic events punching holes in the ozone layer from time-to-time.
Since the 1700s, the ozone layer has been getting steadily thinner.
This gets us to "current events".
The ozone layer is being depleted in last 30 years. It is due to the invention of miracle called CFC chemicals.
Ozone is depleting in the last twenty years. It is due to synthetic chemicals.
It has grown dramatically in the past 30 years.
In the past three years, ozone has depleted. It is because of the use of CFC's.
The ozone has been decreasing since 1970's. Is due to the increasing industrialization.
The ozone hole first appeared when the ozone layer first appeared. The only variable is the "size" of the hole, and the ozone concentration in the "hole". The pole of the Earth that is experiencing winter receives none of the UV that makes ozone (for like a month or more), and ozone naturally decays with time. TThe ozone hole is a normal feature of our ozone layer. It appears each year when it is winter at one of our poles. So it first appeared when the ozone layer appeared. We first noticed the ozone hole in 1985, above Antartica. One forms over the Arctic pole too when it is winter there. They heal closed again once sunlight reaches the pole. Its not so much the presence or absence of an ozone hole, but its size that is important. It is important to look out for the ozone hole
The ozone layer blocks most of the sun's harmful ultraviolet rays. The ozone layer has thinned over time in certain areas due to emissions of ozone depleting chemicals widely used in industry.
The "ozone layer" is roughly the same condition it has always been in. The amount of ozone in the upper atmosphere varies mainly due to variations in solar activity. UV radiation has serious affects on this layer. Holes form over the poles at the end of each winter due to a lack of sunlight. When the sun returns, the "holes" quickly disappear.
You can find ozone in any layer of the atmosphere, but in the lower layers it does not last long. The so-called ozone layer is in the lower portion of the stratosphere, at a height where it takes a long time to dissociate.
In the Precambrian time, 4.6 billion yrs. ago
its changed over time by tectonic plates shifting.
The ozone issue has changed with time. The use of CFC first depleted the ozone but now it is stable.
Yes, the ozone has shifted over time. It changes with weather each season.
The main damage to the ozone layer was caused by freons, with the layer thinning to such an extent over Antarctica that it was referred to as the'ozone hole'. Fortunately, the industrial use of freons was banned, perhaps just in time, and the ozone layer is recovering. Alternative fuels are unlikely to affect this recovery.
The ozone hole first appeared when the ozone layer first appeared. The only variable is the "size" of the hole, and the ozone concentration in the "hole". The pole of the Earth that is experiencing winter receives none of the UV that makes ozone (for like a month or more), and ozone naturally decays with time. TThe ozone hole is a normal feature of our ozone layer. It appears each year when it is winter at one of our poles. So it first appeared when the ozone layer appeared. We first noticed the ozone hole in 1985, above Antartica. One forms over the Arctic pole too when it is winter there. They heal closed again once sunlight reaches the pole. Its not so much the presence or absence of an ozone hole, but its size that is important. It is important to look out for the ozone hole
Ozone layer forms in summer. therefore it initiates its recovery at that time.
The ozone layer blocks most of the sun's harmful ultraviolet rays. The ozone layer has thinned over time in certain areas due to emissions of ozone depleting chemicals widely used in industry.
They use hydrocarbons now; they used to use chlorofluorocarbons (CFC's) which were damaging to the ozone layer.
The "ozone layer" is roughly the same condition it has always been in. The amount of ozone in the upper atmosphere varies mainly due to variations in solar activity. UV radiation has serious affects on this layer. Holes form over the poles at the end of each winter due to a lack of sunlight. When the sun returns, the "holes" quickly disappear.
Yes, you will. There is a lot of time until the ozone breaks up.
You can find ozone in any layer of the atmosphere, but in the lower layers it does not last long. The so-called ozone layer is in the lower portion of the stratosphere, at a height where it takes a long time to dissociate.
The ozone deplete when the world was unaware about it. That is when CFC's were born.