As President Barack Obama prepares to deliver his State of the Union address, we believe it’s a good time to take a look at the state of our climate: the growing impacts of climate change, recent progress in reducing U.S. emissions, and further steps we can take to protect the climate and ourselves.
The consequences of rising emissions  are serious. The U.S. average temperature has increased by about 1.5°F since 1895 with 80 percent of this increase occurring since 1980, according to the draft National Climate Assessment . Greenhouse gases could raise temperatures 2° to 4°F in most areas of the United States over the next few decades, bringing significant changes to local climates and ecosystems.
While there’s been a lot made of a supposed “hiatus” in global warming, 15 years simply isn't long enough to separate a long-term climate trend  from shorter scale climate variability. The clear facts remain that the first dozen years of the 21st Century rank in the top 14 warmest on record, and other measures of the amount of heat accumulating in the earth system, such as ocean heat content , show warming continuing unabated.
Several events remind us of our vulnerability to weather extremes. Deadly floods in Colorado resulted in approximately $2 billion  in damages. Meanwhile, both Colorado and California experienced large and destructive wildfires . In many regions of the country, we have observed an uptick in heavy rainfall events, as well as more expansive wildfires in recent decades. Going forward, climate change in likely to enhance the risk of both these types of extremes.
President Obama put forth a credible Climate Action Plan  in June that includes steps to reduce carbon emissions, especially from power plants, which account for about a third of U.S. greenhouse gas emissions. It also includes steps to increase energy efficiency, expand renewable and other low-carbon energy sources, and strengthen resilience to extreme weather and other climate impacts. Given congressional paralysis , the plan is likely to be the blueprint for federal climate action for at least the next three years.
We’re seeing action at the state level, too. The first full year of California’s greenhouse gas cap-and-trade program , the nation’s largest, has offered proof  that states can take the lead on climate change action. The program is now officially linked to Quebec , showing that action can spread across international borders.
The nine Northeast states in RGGI  now have a stronger emissions cap, which, by 2020, is projected to contribute to a 45 percent reduction in the region’s annual power-sector CO2 emissions from 2005 levels.
California, Oregon, Washington and British Columbia, which together comprise the world’s fifth-largest economy, are working together  to combat climate change and promote clean energy, and eight states are giving a big boost  to zero-emission vehicles by agreeing to support putting 3.3 million on the road by 2025.
But there are some troubling signs that there is more work to do.
U.S. energy-related carbon emissions are 10 percent below 2005 levels, but they crept up 2 percent last year . That's the first annual increase in three years. The Energy Information Administration says it's due to increased electricity demand and also because higher natural gas prices prompted some generators to increase coal use. That's more evidence market forces alone can't be counted on to reduce emissions sufficiently as long as the cost of emitting CO2 is left out of the market.
Meanwhile, global carbon emissions  are rising and, with global energy demand projected to rise nearly 40 percent over the next two decades, will continue to do so unless more of that energy is zero-carbon.
A comprehensive market-based approach that puts a price on carbon  would be the most efficient and effective way to reduce emissions. But as Congress is unlikely to act in the near future, we have to rely on executive branch action.
We hope that in his State of the Union address, the president will continue to make a strong case for climate action. We need to respond strongly and quickly to preserve our environment and our economy.