I am not a teacher.
I don't think you're right.
The tiny quantities of rare gases are threatening to warm the atmosphere. The threat exists now, the warming may come later. It is wrong to say "will threaten".
Carbon dioxide is already warming the Earth's atmosphere. It is assumed that it will continue to do so. The rate of warming due to carbon dioxide over the next fifty years may be exceeded by that due to the tiny quantities of rare gases.
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