@tomster,
o*Net reports on employment trends in the United States. Here's what they came up with when I just put the word "nature" into their search engine -
http://www.onetonline.org/find/quick?s=nature
Code:Relevance Score Code Occupation
100 19-1031.03 Park Naturalists
78 27-4021.00 Photographers
72 19-3092.00 Geographers
70 47-4011.00 Construction and Building Inspectors Green
66 19-2041.03 Industrial Ecologists
65 47-5012.00 Rotary Drill Operators, Oil and Gas
62 11-9121.00 Natural Sciences Managers
58 19-3011.01 Environmental Economists
50 11-9161.00 Emergency Management Directors
49 19-4093.00 Forest and Conservation Technicians
47 53-7071.00 Gas Compressor and Gas Pumping Station Operators
47 55-3015.00 Command and Control Center Specialists
41 19-1023.00 Zoologists and Wildlife Biologists
39 11-1021.00 General and Operations Managers
39 25-9041.00 Teacher Assistants
39 29-1069.07 Pathologists
39 43-5111.00 Weighers, Measurers, Checkers, and Samplers, Recordkeeping
37 19-1031.02 Range Managers
35 11-9033.00 Education Administrators, Postsecondary
35 19-1031.01 Soil and Water Conservationists
Geographers was tagged as "bright outlook", which means that they think there will be a lot of openings in that field within the decade.