Here are the presidential candidates' statements on the Lieberman-Warner Climate Security Act, which lived and died in the Senate this week.

Barack Obama's campaign released a comment this afternoon which said in part:

This is critical and long overdue legislation that represents a good first step in addressing one of the most serious problems facing our generation. Like many of my Senate colleagues, I believe the legislation could have been made even better. Had there been a substantive Senate debate about some of the concerns with this bill, I believe the outcome could have generated broad support. It certainly would have received my support.
Unfortunately, the Republican leadership in the Senate has chosen to block progress, rather than work in a good faith manner to address this challenge. This is a failure of our politics and a failure of leadership — a President who for years denied the problem, and a Republican nominee, John McCain, who claims leadership on the issue but opposes this bipartisan bill.

He continued:

Let me clear, this bill is not perfect. Emissions reductions must reflect the scientific consensus, which are reductions of at least 80 percent 2050. We must ensure that more middle-class families reap more of the financial benefits created by this bill. And we must direct greater resources to the regions of the country that will bear the brunt of this critical transition to a clean energy economy.
I believe that the American people are ready to lead the world on this issue. The time for distractions, divisions, and excuses is over. The time for new coalitions, informed and civil debate, and a sense of shared purpose is long overdue. As president, I am committed to ensuring that our children and our children's children can point to this generation as the time when American found its way again."

Yesterday, John McCain said that were he not campaigning in Florida today, he would've vote with the majority to limit debate and end the Republican filibuster. He made the statement through his Senate office -- curiously, his campaign has been silent on the bill. He also offered these thoughts on the bill:

Like many of my colleagues, I believe this legislation needs to be debated, amended, improved, and ultimately, enacted. While my schedule precludes me from being in Washington, DC, tomorrow to cast my vote, if I were able, I would vote to invoke cloture on the substitute amendment. That does not mean I believe the pending bill is perfect, and in fact, it is far from it. For example, the provisions to impose Davis Bacon mandates* should be removed. Most importantly, it must include provisions championed by Senator Graham and myself that would ensure that nuclear power, a proven and clean energy source, is included among the technologies supported in our efforts to address global warming. Nuclear energy is an emission free source of electricity for the nation, which is why it simply must be part of the comprehensive solution to addressing climate change, and if it is not, I could not support the legislation's final passage.
Unfortunately, despite the commitment and tireless efforts of the bill's sponsors, Senators Lieberman and Warner, it appears that for now, the Senate, at the direction of the Majority Leader, will choose to put politics above policy, and Congress will fail to act yet again on this critical issue. But rest assured, we will not give up until we finally succeed in enacting needed, comprehensive cap and trade legislation to address this urgent problem.

*Here McCain is referring to provisions sprinkled throughout the bill that condition the award of some "bonus" emission allowances to companies that install renewable energy capacity or deploy advanced technologies on those firms paying laborers the prevailing local wage.