By Michael Shank

President Barack Obama must go big on climate change this Tuesday primarily because there will hardly be a better political moment available to him. If President Obama uses his speech to go soft — with meager caps on carbon emissions, weak investments in renewable energy, and an uncourageous picking of low-hanging fruit on energy efficiency — he will have missed his moment. Think of all things that have happened this year that set the stage for an all-in announcement on global warming.

First, we breached the 400 parts per million of carbon concentration in the atmosphere, a dangerous precedent in the slippery slope towards a carbon-consumed climate. This news comes despite President Obama’s continued claim that we’re making progress on reducing carbon emissions in the atmosphere. We’re not. The only good news here is that the Obama Administration raised the social cost of carbon, which estimates the cost of pollution to society, to $38 per ton from $23 per ton.

Second, we witnessed the hottest dozen years in recorded history occur within the last decade and a half, with 2012 ranked as the hottest ever in human history. Hundreds of cities all across America are witnessing record-breaking heat waves, recording temperatures never seen before in their city’s recorded history. Backing up these trends, Science Magazine reported that the earth is warming much faster than we thought.

Third, the Nation Climate Assessment, the 13 inter-agency government body making up the United States Global Change Research Program, reported that a 10-degree rise in Fahrenheit was plausible if warming trends weren’t radically reversed. To put this in perspective, a 2-3 degree rise is considered undesirable but adaptable while a 4-7 degree rise is considered completely unsustainable. So with 10 degrees, forget about it, we’re done.

Fourth, the Government Accountability Office (GAO) raised the level of risk associated with global warming to a “high risk” situation, on par with how it ranks Pentagon-related security risks. The GAO report, furthermore, noted that the government is completely ill equipped to deal with the financial implications from climate change disasters, citing $80 billion in funds owed by the Federal Emergency Management Agency to the US Treasury in less than 10 years of disaster response. And that doesn’t even include the tens of billions from Hurricane Sandy.

Fifth, and most recently, the National Research Council came out this month swinging for a carbon tax, suggesting that it was the only government tool effective enough to save society from rising carbon emissions and the concomitant climate change. The NRC studied the efficacy, or lack thereof, of tax credits, noting that the only tax credits that made a real difference in carbon reduction were the production (PTC) and investment (ITC) tax credits. The PTC and the ITC were the only tax credits making any kind of dent, albeit only 0.3 percent reduction in carbon emissions, by helping public and private sectors switch from fossil fuels to renewable energy.

President Obama, in sum, has ample weather data and his own government agencies on his side here, ready to back him up for a big plan to cut carbon emissions. Whether or not he takes this opportunity to be a foresighted leader who is ready to protect the environment for generations to come is still unclear since Obama has done little to date to do so. This is his time and could be his legacy, and he certainly needs one in light of recent disappointments on the National Security Agency (NSA) and Internal Revenue Service (IRS) fronts.

Unlike those problems, however, which can be remedied more quickly with some serious government reform, a failure to fix global warming now sets the stage for inevitable irreversibility. NSA email safety issues and IRS 501c3 statuses will be minor, unmemorable issues at that point because the safety and the status of our society will be in critical jeopardy.

That is the reality that faces President Obama amidst Tuesday’s climate speech. This is no time for a small pitch on power plant carbon parameters. We need something big if we are to survive at all. Now let’s hope he understands that and does something real to address it.

Michael Shank, Ph.D., is the director of foreign policy at the Friends Committee on National Legislation.