In his State of the Union address, President Obama promised stronger action on climate change.  Today he followed up with a credible and comprehensive plan.  The real issue now is how vigorously he follows through.

From a policy perspective, the president’s plan lacks the sweep, cohesion and ambition that might be possible through new legislation.  With Congress unwilling to act, the president instead is offering an amalgam of actions across the federal government, relying on executive powers alone.

Taken together, the actions represent the broadest climate strategy put forward by any U.S. president, addressing the need to both cut carbon emissions and strengthen climate resilience.  While many of the specific items are relatively small-bore, and quite a few are actions already underway, the plan also includes new initiatives that can significantly advance the U.S. climate effort.

Chief among them is the president’s explicit commitment, for the first time, to regulate emissions from existing power plants, which account for a third of U.S. greenhouse gas emissions.

Here, the plan is short on details, which is not surprising, as it would be unwise for the president to prejudge the outcome of the Environmental Protection Agency’s formal rulemaking process.  But what little the plan does say suggests the administration has the right approach in mind. It directs EPA to “build on state leadership [and] provide flexibility,” which hopefully means allowing states to use the kind of market-based approaches pioneered by California and the nine Northeastern states in the Regional Greenhouse Gas Initiative so utilities can reduce their emissions at the lowest possible cost.

The president directed the EPA to propose standards for existing plants by June 2014 and finalize them a year later. That’s an ambitious timeline – but one fitting the true urgency of the challenge.

The plan includes a wide array of other measures to reduce greenhouse gas emissions, improve energy efficiency, and promote renewable energy and other low- and no-carbon energy sources.  And it outlines ways the administration will work bilaterally and multilaterally to strengthen international climate efforts.

Importantly, though, the plan also devotes equal attention to the other side of the climate equation – helping communities and businesses better cope with extreme weather and other climate impacts.  Even with ambitious efforts to cut emissions, we face rising climate risks, and it’s critical that the federal government do all it can to help strengthen America’s climate resilience.

In the long run, we need much more than the president’s plan promises.  Hopefully in time, growing public concern will force Congress to take meaningful climate action – ideally, by enacting an economy-wide price on carbon, the most cost-effective way to curb our carbon emissions.

But for now, President Obama has outlined a realistic strategy, one that by design he can execute with tools already at his disposal.  The path forward will entail political risks, but they are risks worth taking to spare future generations the much greater risks of a warming world.  Having put forward a plan, the president must now have the fortitude to see it through.