What is the biggest threat for human race according to you?

Explanation:

The biggest threat for human are human, (so ourself) or pollution

Sorry for my English.

Climate change, it is a serious crises that will determine the future of the human race. Since our planet is protected by the Ozone layer, and we continue to burn holes into it through manufacturing and other toxins. Causing the temperature to rise higher each year and eventually melting the north and south pole.

If we continue to ignore this problem well eventually become the next Mercury

The generation when dominant deleterious alleles are expressed. It is the time when the negative effect comes out and affect the fitness of an individual. If an individual only carries one recessive deleterious allele it would have a different effect and would stay healthy. However, the next generation from this individual would inherit the deleterious alleles and have the said negative effect.