Answer:
Methane is found deep in the Earth's crust, which makes it difficult to harvest
Explanation:
According to the Scientific American: "With drillers tapping into massive stores of natural gas across the United States, scientists are researching ways to capture it more effectively". On the same article, you can find that: "Energy companies are looking for a cheap way to separate these gases to yield a pure methane stream". So it is hard and expensive to harvest methane, even though drillers keep finding it.
Answer:
Methane is unstable, so harvesting it has to be done carefully, which is expensive.
Explanation:
Methane hydrates are like fossil fuel's evil cousin. They form after bacteria breaks down organic debris, which then crystalizes under the high pressure and low temps at the bottom of the ocean. Similar to fossil fuels, these crystals burn easily, meaning they're an efficient source of energy. However, unlike fossil fuels, collecting these crystals can be tricky, and deadly, due to one small problem. They kind of explode when disturbed. That's not a big deal, right? Oh, they also easily disintegrate, causing the seafloor to become unstable and collapse, which can cause landslides. Like I said, evil cousin.