President Obama and Mitt Romney in the first of three presidential debates.

Big Bird might have been one of the most popular trends on Twitter during the first presidential debate between Mitt Romney and Barack Obama. But as the discussion of domestic issues unfolded, #climatesilence got some play as well. Sadly, not because the candidates broke their silence on the issue.

Here are two tweets that summed up the lack of attention to climate change:

And this one from climate activist Bill McKibben:

If you watched the real-time reaction to the debates, the disappointment among folks within the energy and environment community over the lack of attention to climate was palpable. Even with 160,000 signatures delivered to PBS’s Jim Lehrer calling on him to ask the candidates about climate change, the issue was completely ignored during the 90-minute conversation — continuing a long streak of silence throughout the campaign.

Apparently, neither of the candidates has been watching the polls showing that climate could be a major factor in how undecided and independent voters cast their ballots.

Energy issues were sprinkled throughout the debate, however. The mentions were focused mostly on domestic drilling and clean-energy spending.