US Senator Lindsey Graham of South Carolina became the ninth contender for the Republican presidential nomination earlier this month. He is a staunch conservative who tends to vote with his party on everything from gun control to health care and foreign policy. He is also the first Republican candidate to squarely address the question of climate change — in a constructive way. During an interview on the CNN news channel on 7 June, Graham highlighted the problem and issued a welcome challenge to his fellow Republicans.

 “Here’s a question you need to ask everybody running as a Republican: what is the environmental policy of the Republican Party?” Graham said. “When I ask that question, I get a blank stare.”

Graham could not be more correct. It has been clear for some time that climate change is a defining social, and therefore political, issue for the twenty-first century. Questions remain about what kind of impacts to expect and how best to reduce greenhouse-gas emissions, while extending the benefits of modern industry to the world’s poorest citizens. But the core science is solid, and policy-makers at all levels have a responsibility to engage with it. Sadly, the Republican Party’s strategy in Congress thus far has been to ignore or dodge the problem, or to deny it outright.

Fellow candidates such as senators Marco Rubio of Florida and Ted Cruz of Texas have both questioned the science of global warming or humanity’s contribution to it, as has former Pennsylvania senator Rick Santorum. When the US Senate took up a pair of symbolic resolutions in January, just 15 Republicans voted in favour of an amendment declaring that human activity contributes to climate change, and only 5 were willing to support a resolution stating that the human contribution is significant.

The rest of the world has moved beyond questions about whether climate change is real.

So far, the only significant Republican engagement on climate has come in the form of opposition to regulations being imposed by the administration of President Barack Obama. Those regulations are in place for cars and trucks, and the administration is expected to finalize a rule to limit carbon pollution by the electricity sector as early as next month. Just last week, the Environmental Protection Agency released a draft “endangerment” finding that will enable the agency to regulate emissions from aeroplanes, in accordance with standards being negotiated through the International Civil Aviation Organization.

Many on the right — including Senator Graham — have argued against these regulatory efforts, and there are legitimate reasons for doing so. Most experts agree that it would be much more effective to tackle the issue in a comprehensive way, whether through a market-based regulatory emissions scheme like that adopted in the European Union, or a simple carbon tax. An insurgent environmental faction in the Republican Party is pushing for the latter, perhaps paired with a dividend system that would make the tax revenue-neutral and offset the higher prices paid by consumers for petrol and for fossil-fuel-based electricity, as a simpler conservative solution. But before they can even think about laying out a proactive agenda, Republicans must acknowledge the problem.

In this sense, Senator Graham’s challenge is a step forward. Not only is it in line with main­­stream science, but it also chimes with mainstream views within the US public. A March survey by the Yale Project on Climate Change Communication found that 63% of Americans believe that global warming is happening and 52% think that it is mostly caused by humans; just 18% think that it is not happening, with 32% believing that it is mostly due to natural environmental factors. Also, 71% of Americans “mostly” or “somewhat” trust climate scientists, compared with 27% who mostly or somewhat distrust them. Even the corporate community that Republicans claim to represent is beginning to engage with climate change. And Pope Francis has issued his own call to action on climate change this week (see

The rest of the world has moved beyond questions about whether climate change is real and is focused on how best to address it. There is plenty of pressure on Republicans to do the same, but the challenge to party orthodoxy ultimately needs to come from within. Senator Graham has put the problem on the Republican presidential agenda. To build momentum, he and other brave souls will now need to start talking about solutions.