Blogger required for ongoing eco-related posting

I'm building a new blog focused on carbon offsets. I'm looking for someone who can, on a daily basis, blog posts that review and relate to news items about carbon offsetting. I'm keen to find experienced an writer with a passion for green issues who can contribute on an-going basis. Google news provides a fertile ground for sources of news, but I'm looking for someone who can add value to the stories through commentary, opinion, and if necessary basic additional research on the topic. The key is these posts will feature on the sites homepage so must be original, relevant and newsworthy. Posts should be around 350-600 words and the project will be budgeted on the basis of 4 posts a day for 15 days, although if successful I would like make it a regular project. Clearly excellent english is a must and examples of previous work or evidence of experience expected.