Unfortunately, environmentalism is a topic where there is a lot of conflicting opinion and misinformation on the Internet. If you're concerned about the quality of your information sources, try these:
In addition to GREENR (above), use these databases to find scholarly journal articles, news, and other in-depth information about environmental science and engineering:
There are a large number of well-known consumer and political organizations concerning the environment. However, there are other organizations for engineers and other scientists. By joining a professional organization, you are more likely to learn about the latest research and technological discoveries. Some have "student memberships" for lower costs. Here are a few: