Hi~~
The carbon cycle and water cycle are biogeochemical cycles. How do they intersect? Well, the most obvious one is because of photosynthesis. Plants take carbon dioxide (carbon) and turn it into water (h2o). The second one should be because carbon dioxide is very soluble. carbon dioxide is often found in our oceans, where marine organisms take them, die, and it gets absorbed by rocks... the rocks then release it, the oceans or the plants absorb it, and the cycle repeats.