Kamala Harris is trying not to step in it. As the California Senator turned presidential candidate tours a beef-and-produce farm in south-central Iowa on Aug. 11, a crouching campaign aide carefully walks a few feet ahead, pointing out the cow droppings littering the grass. The farmer strolling next to Harris, a bespectacled 49-year-old named Matt Russell, wants to talk about climate change. “Farmers and rural Americans, that’s who’s going to solve this,” Russell says to Harris as the two stroll accompanied by a bevy of cameras in front of his red barn. “We have the land for renewable energy, and we have the farming systems to sequester carbon.”

The trip to Russell’s 110-acre farm is becoming a habit for the Democratic candidates for President. Ohio Representative Tim Ryan visited before launching his campaign, and former Texas Congressman Beto O’Rourke stopped by in June. Russell has also chatted with Minnesota Senator Amy Klobuchar and South Bend, Ind., Mayor Pete Buttigieg elsewhere, and hopped on the phone with staffers for Massachusetts Senator Elizabeth Warren and former Vice President Joe Biden, among others. But he’s hardly the only Iowan giving candidates an earful on climate change. Across the state, Democratic presidential hopefuls have heard from business owners whose storefronts have flooded, mothers concerned about contaminated drinking water, and farmers who have lost harvests to a cycle of flooding and drought in the state. “There is deep concern about climate change across Iowa,” says Michael Bennet, a U.S. Senator from Colorado currently running for the Democratic nomination. Survey after survey of Iowa Democrats have identified global warming as one of voters’ top two issues, right after health care and ahead of immigration and the economy, among others.

In previous elections, climate change was essentially a nonissue. A Pew Research poll released three weeks after the 2008 Iowa caucuses found that just 1% of Americans ranked the issue as the nation’s most important problem. Eight years later, Hillary Clinton and Donald Trump debated three times without facing a single question about climate change.

In the early stages of the 2020 campaign, things looked much the same: many Democratic campaigns offered little more than boilerplate support for a Green New Deal or an endorsement of the Paris Agreement. But over the course of the race, climate change has emerged for the first time as a top-tier presidential campaign issue. A slew of factors have contributed to the spike in national interest, from the activists pushing for a Green New Deal to the warning for urgent action embedded in the landmark Intergovernmental Panel on Climate Change (IPCC) report released last year by the U.N. to Washington Governor Jay Inslee’s climate-focused presidential campaign, which raised the bar for other candidates. But climate’s growing political clout is also due to the reality of daily life in Iowa, whose outsize importance in the presidential primaries has forced candidates to finally pay attention.

Climate change has become a top issue in the 2020 presidential race. Clockwise from top left: Justin Sullivan—Getty Images; Charlie Neibergall—AP; Mandel Ngan—AFP/Getty Images; Mark Kauzlarich for TIME

Since late April, all the major Democratic candidates have released comprehensive climate plans, addressing everything from the details of new research-and-development funding to how they would support other countries’ climate efforts to how they would change permitting rules for new oil-and-gas pipelines. Several presidential hopefuls have proposed ideas tailored for Iowa, including new climate-insurance programs for farmers and new agricultural-research agencies. At multiple Iowa campaign stops in August, Ryan spoke at length about how farmers might one day receive government funding for capturing carbon dioxide in soil. New Jersey Senator Cory Booker has proposed funding programs to give farmers expanded access to renewable energy. “At every event, the candidates will talk about climate change,” says Rob Hogg, an Iowa state senator from Cedar Rapids who has hosted town halls.

Sign up for One.Five, TIME’s climate change newsletter

This is a glimpse of what’s to come in U.S. politics, as the country contends with the creeping menace of climate change, from rising seas in Florida to wildfires in California. “Extreme weather events are waking people up,” says Steve Shivvers, a retired agricultural equipment company CEO from Des Moines, who is active in local climate groups. The climate challenges Iowa faces today help explain why scientists and advocates are so eager for the issue’s political salience to catch up to its ecological and economic importance. In the long run, that may be inevitable. The question is whether the politics change radically enough before the climate does.

Jim Lykam knows Davenport like the back of his hand. The Democratic state senator has lived in this city on Iowa’s eastern border his entire life, and as he drives me down Davenport’s empty back roads he recalls how it has been defined by its most powerful resident, the Mississippi River. Lykam, 69, points to the little adaptations that have sprouted over the decades, designed to make life on the river bearable: a dirt barrier one business owner constructed to prevent flooding; elevated homes resting awkwardly on cinder blocks.

But this past spring, the combination of persistent rain and high water levels from fast-melting snowpack caused Davenport’s levee system to fail. Downtown was inundated; the city’s main thoroughfare was underwater. In total, the economic impact ran to some $30 million. Driving through town, you can still see the marks on doors and windows where water levels stagnated, in many cases for as long as two months. Parts of town were inaccessible for even longer than that. “They call them 100-year floods,” says Lykam. “We’ve had three of them in the last 15 to 18 years.”

The flooding in Davenport is just one example of how climate change and extreme weather have rocked Iowa. Throw a dart at a map of the state, and you’re likely to hit a place that has flooded in recent years. In the past year alone, nearly 40% of Iowans have personally experienced anxiety over extreme weather or know a family member who has, according to a July survey from Climate Nexus in partnership with Yale and George Mason universities.

This isn’t a surprise to scientists. Warmer air holds more moisture, which creates the potential for bigger storms, a problem that will leave few corners of the globe untouched. Across Iowa, the annual precipitation level averaged less than 33 in. during every decade of the 20th century. For the first half of this decade, average precipitation tops 36 in. An analysis from Iowa State University released earlier this year found a greater than 90% chance that global warming has driven the spike in the state’s late-spring floods.

Voters across Iowa say the real-life effects of climate change have sparked a political awakening of sorts. Hogg, the state senator from Cedar Rapids, says record flooding in 2008 all but eliminated climate-change skepticism in the city. Recurring flooding contributed to the Iowa City council’s recent decision to declare a climate crisis. The council made a commitment in August to reduce the city’s greenhouse-gas emissions 45% by 2030. “It’s not just about climate strikers,” says Iowa City Mayor Jim Throgmorton, referring to the global movement of schoolchildren striking to call for action on climate change, and “not just about the IPCC report, but also about our own experience and own observation.”

Flooding, and the extreme precipitation that caused it, has had a range of effects across Iowa, disrupting the cycles that farmers rely on to plant, grow and harvest their crops. This spring alone, extreme rain put 100,000 acres of farmland underwater in the state, resulting in tens of millions of dollars in damage to farmers. To top it off, July was exceptionally dry, throwing another wrinkle at farmers. By 2050, climate change threatens to erase all the gains made in agricultural productivity since the 1980s in the Midwest, meaning farmers will need to spend heavily or cut production, according to the National Climate Assessment, a report from more than a dozen U.S. federal agencies on the impacts of climate change.

Surveys have historically identified farmers as skeptical of climate science, but in Iowa there are hints that this may be changing. Aaron Heley Lehman, president of the Iowa Farmers Union, says climate has become a regular topic of conversation among farmers. Greg Franck, a self-described “farm boy” who lives in the Des Moines area but has worked in agriculture, described a recent meeting he attended in southwest Iowa, where farmers gathered to hear advice from federal government scientists on how to adapt to the effects of climate change. “There’s hope there,” he says.

The surge of interest explains why Democratic candidates have become increasingly attuned to climate issues as they crisscross the state. At campaign stops in rural areas in the summer of 2019, the grim future for farms in a climate-changed world was a frequent subject of questions for presidential candidates. In urban areas, concerns about climate change often come up through discussions about water quality, since spikes in precipitation and flooding have swept chemicals in agricultural soil into the water supply. The town of Pacific Junction, near the state’s western border with Nebraska, has become a frequent stop for Democratic presidential candidates since a levee breach nearly wiped it off the map earlier this year. “It’s a reminder,” Warren said on a Aug. 7 visit. “Everything is changing.”

Conversations like these have translated into policy proposals. In April, O’Rourke was the first Democratic presidential candidate of the 2020 campaign to release a comprehensive climate plan, calling for a $5 trillion investment and the elimination of greenhouse-gas emissions by 2050. Many climate advocates lauded it, but they weren’t his only audience. After the former Texas Congressman spent weeks on the trail in Iowa—including a visit with Russell—O’Rourke updated his white paper with more robust provisions to help farmers, including a funding stream for those who sequester carbon dioxide in their soil.

By the time the Iowa State Fair rolled around in August, at least seven Democratic candidates had put out similar proposals, from Booker’s pledge to provide the Department of Agriculture with tens of billions of dollars in conservation funding to Bennet’s idea to create a new research agency to focus on climate solutions for farmers. “Candidates are not just showing up and walking through the state,” says Russell. “They’re sitting down and listening.”

None of this is to say that climate change will be the defining issue of the Democratic primary or that Iowans are now single-issue voters. And while the presidential hopefuls have all committed rhetorically to the cause—using language like “existential threat” and “climate crisis”—the strengths of their plans and commitments to the cause vary.

For many of the candidates, climate change has thus far remained a secondary concern in their careers with few of the members of Congress in the race having proposed comprehensive climate legislation before this year. And many still haven’t met the demands of today’s climate advocates. Klobuchar’s­ plans center on restoring initiatives begun during Barack Obama’s presidency, short of what climate scientists say is necessary, and she has described natural gas as a “transition fuel,” to the derision of environmental campaigners.

When Harris visited Russell’s farm in mid-August, it was clear that the California Senator was more comfortable discussing run-of-the-mill agricultural issues than the specifics of the policy Russell suggested. “Farmers are innovators,” Harris responded when Russell talked about farmers capturing carbon with their agricultural practices. “As they say, farmers’ almanac. But really, it’s about you who are so close to the ground really having an understanding of what it tells us and knowing how to then use all these natural elements in a way that is maximizing productivity.” (Harris later released a comprehensive climate plan.)

Many Democrats, especially in Washington, believe bread-and-butter issues like health care and the economy should remain at the core of the party’s message. That may be why members of the Democratic National Committee rejected requests from activists and candidates to sanction a debate focused entirely on climate change. In a June statement, DNC chair Tom Perez seemed to dismiss climate as a pet issue for Inslee, saying he “could not allow individual candidates to dictate the terms of debates.”

Still, of the two dozen voters I interviewed throughout Iowa in August, nearly every one brought up climate change unsolicited, from the Democrats staked out to catch the candidates’ stump speeches at the Wing Ding dinner in Clear Lake to the crowd following Harris around the Iowa State Fair. Rachel Wilke-Shapiro, a preschool teacher in Des Moines and a Harris supporter, complained that the national narrative around climate change hasn’t caught up with the reality she sees on the ground. “You have to explain to them why it’s their 3 a.m. issue,” she says. “People don’t always tie it together.”

In the drizzling rain, Mitchell Hora walks me to the top of a 40-ft. grain bin on his family’s farm in southeast Iowa’s Washington County, where his family has worked for seven generations. Even to my untrained eye, it’s clear that the Horas’ 800 acres of corn and soybean crops are thriving while his neighbors’ fields are dotted with patches of dead plants. The difference, he says, is that he changed growing practices in recent years, planting different crops on the same fields as the corn and soybeans he sells, a practice known as planting cover crops. He’s reduced pesticide use and stopped tilling the land, which keeps key nutrients in the ground. All of these practices, he says, have improved his yield. It’s good news for his farm, but it’s also good news for the planet. Agriculture accounts for nearly 10% of U.S. greenhouse-gas emissions. Hora’s new practices store carbon dioxide in the soil, meaning there’s less of it in the atmosphere.

These are big changes for farmers accustomed to traditional growing practices. But the farmers implementing them aren’t radical—Hora, whose family home is decorated with Bible verses and other religious items, makes clear that he’s “not a hippie.” The changes he has made, much like those of the state at large, are another sign that most people, regardless of their political leanings, are ready to talk about solutions. “We need to farm more sustainably,” says Hora. “It’s going to make us money and make us more economically resilient. And it’s also good for the environment.”

Democrats have tapped into that conversation. At least 10 candidates have proposed to offer farmers an additional income stream if they implement climate-friendly practices. “What we’re seeing is a significant change in how the Democrats are engaging with farmers in rural America,” says Russell.

This approach can provide a model for candidates to follow long after the Iowa nominating contest is done. Climate activists say Democrats have an opportunity to connect with voters by putting forth equivalent policies for communities across the country. “For far too long, climate policy has stayed in the realm of carbon and inanimate things,” says Varshini Prakash, co-founder of the Sunrise Movement, an activist group that advocates for the Green New Deal. Politicians need to “tie it to what Americans are concerned about on a daily basis.”

Many of the early primary states face climate-related challenges. In New Hampshire, whose voters go to the polls a week after Iowa’s, a $9 billion recreation industry is vulnerable as ski runs melt early and local lakes face a potential decline in water quality. Scientists say parts of Nevada, the third state on the Democratic primary calendar, could be virtually unlivable by the end of the century; Las Vegas is warming faster than any other major city in the country. In South Carolina, the fourth state where Democrats will vote in 2020, coastal cities flood regularly and inland rivers are often inundated. Across the U.S., 9 in 10 Democratic voters say they are concerned about climate change, compared with 44% of Republicans, according to a national survey conducted by Climate Nexus, also in partnership with Yale and George Mason universities, released on Sept. 4. As in Iowa, the issue ranks second nationally only to health care as a priority among Democrats.

This is all no surprise to Inslee, who dropped out of the presidential race last month after running the most climate-change-centered campaign of any candidate in history. “We still have too many people who are trapped by the past,” he told me over a beer in Polk City, Iowa. “Maybe 10 years ago, this was not a first-tier issue in voters’ minds. But it is now.”

This is one article in a series on the state of the planet’s response to climate change. Read the rest of the stories and sign up for One.Five, TIME’s climate change newsletter.

Write to Justin Worland at justin.worland@time.com.