The Church teaches that we can know some things about God through natural revelation (or natural theology). This means that a person can look around them and reasonably conclude that there is a God. We can also learn some things about God from nature, which is that he is beautiful and rational. We cannot learn everything about God from nature, and thus we still need divine revelation.
Unfortunately, nature sometimes gets a bad rap among Christians. Obviously, some view nature in a non-Christian way, such as worshiping it or believing it to be God. Others are so extreme in their views of nature, they denigrate the role of humans. Some Christians overreact and make their fellow Christians feel bad about encountering God in nature, or working to conserve our environment.
However, respecting and loving nature is fine, because nature is sacramental. Obviously, Catholics believe in seven sacraments proper, but we can also speak of nature having a sacramental character, because it is a way in which we can encounter God. The ancient Gnostics (and there are some modern ones too!) believed the material world was evil, and that the goal of the enlightened Christian was to escape this evil material world, created by the evil god. Catholics have asserted that the material world is good, and that God uses his good creation for his purposes.
Thus, a Catholic can love nature, because it is part of God’s good creation, and is a tool to know God. When God became human in Jesus the entire course of creation changed. This is why sometimes when I would hike in the winter, I would pick up some snow and refer to it as “redeemed snow.” So, go out and pray in nature. Connect to God’s good creation, and get to know the Creator a little better through it!