On Thursday, San Francisco billionaire climate activist Tom Steyer is launching a new online campaign Thursday in Washington, D.C. to turn up the heat on his friend President Obama to do more to take on climate change — starting with urging him again to oppose the proposed Keystone XL pipeline. Called “We Love Our Land,†it will run at least 10 weeks and be based largely on Facebook, Twitter, YouTube and later, Change.org. If some street demonstrations grow out of this, fine, organizers said, but that’s not the point. It is an argument aimed squarely at Obama supporters who are disappointed that he hasn’t done more on climate change.