I have actually declared my political orientation. I am an independent, with libertarian leanings. I am on record as having contributed to Obama’s first campaign.
The potential problem is issue advocacy by scientists – in this case scientists advocating for specific policies or ‘urgent action needed.’ It is the job of scientists to to be reflective and be aware of their own biases, and to minimize their impact on their science. This is why I often post about biases and advocacy, to raise awareness of these issues among scientists.