At this point in time the humanity has nothing to offer to any other intelligence (if there is any) out there, nor it doesn't have a need itself to go outside of its own planet, and the big mess that it made out of it. It's akin of letting a toddler walk out of the door and roam into a busy street merely for a satisfaction of its curiousity. What is more likely to happen is that the valuable resources that we still have will be gone (it won't take long, as consumption is growing at exponential rate), without ability to recover - a one way ticket to stone age. It's nice to dream and look at the stars, but can we please sort the shit here first?