Geologists study rocks, minerals, and the physical processes that create and change the earth's landscape. There are several areas of geology one can pursue, and some geologists spend more time outdoors than others.
If outdoors is where you want to be, look into becoming a field or exploration geologist. They do geological surveys and mineral prospecting that requires them to spend quite a bit of time outdoors.
Environmental engineers spend roughly fifty percent of their time outdoors, helping project managers with field work and doing environmental site assessments. Their other duties may include installing remediation systems, taking soil tests, and surveying monitoring wells.