Answer:
Because they happen naturally.
Explanation:
climate changes are natural to our planet and happen over time, according to the factors that act on the planet. In this way, climate changes should not be a concern for us, the problem is the speed with which they are happening.
Human activities use a lot of fossil fuels that stick to the atmosphere and accelerate these changes, which cause serious problems in the life of the planet.
These currents are on the oceans surface and in its depths, flowing both locally and globally.
