Rising concern: Geologist Harold Wanless takes a stroll through flooded Miami streets. Only the people seemed to take it in their stride, perhaps because this sort of thing is no longer unusual in and around Miami. A couple of days later I stood on a sealed road in a park in the southern suburbs of Miami – again ankle deep in water – with Harold Wanless, chairman and professor at the Department of Geological Sciences at the University of Miami, to discuss why the place was so wet. The answer was not complicated. "The ocean has risen," he says with laugh. "It is what it is." While much of the nation argues about whether or not California's once-in-a-thousand-year drought or the $US71 billion devastation of Hurricane Sandy might have been caused or exacerbated by climate change – or indeed whether or not the phenomenon even exists – in Southern Florida today you wander about in the water and see what it looks like when rising seas hit a modern western city. As with every other serious issue facing the United States, the acceptance of climate science has fallen down along partisan lines.

It is generally accepted among leading Democrats and often denied – or at least ignored – by Republicans. President Barack Obama twice campaigned on the need to address climate change, though for most of his presidency it has rarely been his focus. Back in 2009, a Democratic bill to introduce a cap-and-trade system to limit greenhouse gas emissions stalled in the Senate and was quietly put to death after Republicans won control of the House of Representatives in 2010. Without control of congress, the President has taken to building a climate agenda piecemeal; using his presidential authority rather than legislation. He set targets of reducing America's carbon pollution by 17 percent from 2005 levels by 2020 and an 80 percent reduction by 2050, and used whatever levers of power he had control over to work towards those targets.

He has introduced and expanded fuel efficiency standards for America's cars, and more recently its fleet of heavy vehicles. In 2013 he ordered federal government agencies to triple their own use of renewable energy to 25 per cent by 2020. Then, in September this year, the Obama administration appeared to get serious about its environmental program. That month the White House announced the president would use his authority over the Environmental Protect Agency to circumvent Republican opposition in Congress to act on climate change. He announced the EPA would simply direct power plants to cut their emissions by 30 per cent of 2005 levels by 2030. The backlash from Republicans and many industry groups was savage. A conservative think tank called the National Center for Public Policy Research published a list of the "Top 10 Reasons Washington Should Not Impose New Global Warming Laws or Regulations."

Number one declared: "The world is not warming" and had not warmed "since the Clinton administration". Number two argued: "Anti-global warming laws hurt people. All the major legislative and regulatory proposals to combat global warming kill jobs and disproportionately hurt lower-income people and minorities." In coal mining states where Democrats could once have relied on strong union support, voters appeared to agree during the midterm elections in November. Republicans ran successful campaigns in Kentucky and West Virginia arguing that Obama was prosecuting a "war on coal". Unmoved by his party's drubbing in that election, Obama has continued to act on climate change. Days after the election he announced that the US had come to an agreement with China to limit the two nations' emissions. China would reach a peak of emissions by 2030 – the first deadline it had set – while the US would accelerate its own reductions by as much as 28 percent from 2005 levels by 2025. The deal had the effect of galvanising international campaigning for a significant climate deal in next year's international climate talks in Paris. Coming as it did on the eve of the G20 meeting in Brisbane, the announcement also served to focus on countries that were not seen to be pulling their weight.

John Boehner, the Republican Speaker of the House of Representatives, thundered at the time: "This announcement is yet another sign that the president intends to double-down on his job-crushing policies, no matter how devastating the impact for America's heartland and the country as a whole." Obama forced the issue further that week by announcing a $3 billion contribution to the United Nations Green Climate Fund that facilitates poorer countries' investments in clean energy. Back in America there are some signs that popular concern about climate change is beginning to increase. A 2014 poll by the Yale Project on Climate Change Communication shows majorities of women, minorities and young people support candidates who strongly endorse climate action, the New York Times reported earlier this week. "That poll found that 65 percent of Hispanics, 53 percent of blacks and 53 percent of unmarried women support candidates who back climate-change action." As the Times noted, those were all groups crucial to the outcomes of the 2008 and 2012 presidential elections.

To the frustration of Wanless, some of the regions feeling the impacts of climate change are governed by Tea Party-backed Republicans, who do not accept what their scientists are telling them. Among this branch of the Republican Party it is popular not only to object to the new EPA regulations, but also to advocate the abolition of the agency. As Wanless and I walk along Matheson Park Road, a family of little white ibises wading a few steps ahead of us, he explains why this area is already being regularly inundated. Not only is much of the region just 1.5 metres above sea level, much of it is built on porous limestone. As the sea levels rise – and since 1930 they have risen about 30 cms says Wanless – the water rises in the ground itself. Residents and businesses started noticing the periodic flooding just a few years back. On full moon high tides the streets would often fill and the lower-lying areas would be inundated. Choked with water, many of the sewers failed.

Wanless remembers when he first started getting calls for help from local authorities. "In around 2008 or 2009, one of the first years we had a lot of water in the Miami Beach area, the public works people called me for help and I went into this room in their government building and they were all in their coats and ties and they said, 'We are having a little problem in Miami Beach, we are getting water in the streets. Where do you suggest we put it?' "I held my laughter. The ocean had arrived. You can put the water anywhere you want, but it is going to keep coming." Wanless believes the hundreds of millions of dollars that have already been spent of flood mitigation infrastructure around Miami have been wasted because the sea cannot be held back. "We are in the position where we think we are going to fight it and win. We are not going to win."

Soon, he believes, insurance companies will stop underwriting homes in the worst affected areas and then owners will be unable to sell. Money should be saved for moving people away while all levels of government work to reduce emissions, he argues. To that end he has few kind words to say about Florida's governor Rick Scott, who, when asked if he believes in climate change, uses a line that has become common among Republicans: "I'm not a scientist". In August Wanless was one of five scientists granted an audience with Scott after a group of 42 of them wrote to him imploring him to take climate change more seriously. Wanless was unimpressed with the meeting. Scott, he says, told him he was "not a cause person, I am a solution person".

Since he was re-elected in November, Scott, who is so closely linked to the energy company Florida Power and Light that one member of his transition team was a company executive, has cut subsidies for solar power. Asked what he thinks about politicians who dismantle programs already in place to help ameliorate climate change, Wanless is direct. "It is sort of what I would call criminal. It is unbelievable that people are so in the hip pocket of … industries and lobbyists that support them that they can't do what is in the interests of the people, this generation and the next generation," he says. He is as scathing of Florida senator Marco Rubio, known for his presidential aspirations, as he is of Scott. Rubio, he says, once accepted climate science, but since then has won Tea Party support and rejected it.

Wanless seems as much fascinated by the impact of climate change as he is disturbed by it. As we splash along the road he stops to inspect the mangroves along the sides, he points out where the water has driven sand from the bay across the hardtop, he chats about his time investigating the rising water around South Beach. He laughs when he tells of the low-slung sports cars that prowl the strip and how their drivers often mistake the salt water that has flooded up through the pipes onto the road for fresh water from a broken main. "They drive straight into it, they have no idea what they are doing to their cars," he says with delight. "Ha! Fools!"