Dennis Publishing's The Week will produce a bonus issue focusing on environmental issues,but will not be distributing it in print form. The extra issue, due out April 20, will be online only.

It's the first time The Week will have published a themed issue - and its first time publishing an issue solely online, writes the New York Times (via MediaBuyerPlanner). Nonsubscribers will also be able to read the issue, which will remain online for a week.

The online-only issue does not replace a print issue because the magazine normally publishes only 48 issues a year and did not plan to publish that week. The prior week's will be a double issue.

The special issue is being sponsored by Lexus, showcasing its hybrid products, and marks Toyota's first time advertising with The Week. The cost of sponsorship, which also includes an event in Los Angeles, is estimated at $500,000.