A principle for international policy development such as with climate change, adopted by the 1992 Rio UN Conference on Environment and Development was: "When an action causes a threat to human health or the environment, precautionary measures should be taken even if some cause-and-effect relationships are not fully established scientifically." This is called the principle.
a. environmental
b. precautionary
c. humanity

b. precautionary

Explanation:

A principle for international policy development such as with climate change, adopted by the 1992 Rio UN Conference on Environment and Development was: "When an action causes a threat to human health or the environment, precautionary measures should be taken even if some cause-and-effect relationships are not fully established scientifically." This is called the  precautionary principle.

they use tree rings to figure out weather patters.

it would be 2 or b because the clouds are a form of condensation