This post originally appeared  in the National Journal's Energy Experts blog as a response to the question: "What Is Climate Silence Costing Us?"
The recent silence on climate change in the U.S. political discourse is extremely troubling. As we can see from the recent spate of extreme weather events , the costs of inaction are clear in terms of both environmental and economic impacts. If we are going to meet the challenge of the global climate threat , we need to have a real, rational discussion about climate change. Having that discussion requires national leadership on this issue.
The irony is that despite the relative silence on the campaign trail, U.S. public opinion on climate change is shifting , with a growing number of people recognizing that more needs to be done to address this issue. As WRI’s president Andrew Steer said  in a recent New York Times interview, “On climate change, the political discourse here is massively out of step with the rest of the world, but also with the citizens of this country. Polls show  very clearly that two-thirds of Americans think this is a real problem and needs to be addressed.” Evidence of the impacts of climate change is already visible. Just look at the growing number of recent extreme weather  and climate-related events: record heat waves, more frequent and extreme rainfall, coastal flooding, Arctic ice melt, longer and more intense droughts , increasingly severe wildfires  – all consistent with what scientists have long considered to be likely outcomes of a warmer world. Meanwhile, in recent months, several authoritative studies have drawn links between specific extreme events and climate change. A study by scientists from NOAA, the UK’s Met Office, and other institutions, published in July, attributed  a number of recent extreme events to human-induced climate change by focusing on the probability of those events. In March, a report from the IPCC found  that climate change has already contributed to changes in extreme events—such as heat waves, increased temperatures, and heavy precipitation—in many regions over the past 50 years. And, an article in Nature Climate Change linked  heat waves and precipitation extremes to human-induced warming. Many of these conditions are only projected to get worse, unless we move to more aggressively cut greenhouse gas emissions.
The monetary costs are also staggering. Economic damages associated with extreme weather and climatic events are severe, whether from drought that destroys crops, sea level rise that threatens our coastlines, or floods and wildfires that damage our homes. According to a recent DARA and Climate Vulnerable Forum report , “Failure to act on climate change already costs the world economy 1.6 percent of global GDP, amounting to $1.2 trillion in forgone prosperity a year.” The report further noted that those costs are expected to double by 2030 due to rising temperatures and greenhouse gas emissions.
At the same time, the United States risks edging itself out of a global clean energy market  with tremendous growth potential, ceding ground to countries like China and Germany, as it stays stuck in an outdated energy system.
We need our elected officials to break their silence on climate change. Whether climate change comes up in the final days of the campaign or not, the next president and Congress will need to step up and do more on this issue. Otherwise, America will face increasing economic and environmental consequences while also falling further out of step with the rest of the world.