A 40-mile ribbon of road wraps around northeast Oahu, connecting Kaneohe with Haleiwa.

It’s the only access to the rural communities of Kahaluu and Kaaawa, home to numerous Native Hawaiians and Pacific Islanders among several thousand other residents. Dotted by shrimp trucks, this stretch of Kamehameha Highway also serves the prep football stronghold in Kahuku and the Mormon enclave in Laie.

Surfers rely on the two paved lanes to access the world-renowned Pipeline and Waimea Bay breaks. And vacationers use them to reach seaside alternatives to Waikiki.

VIDEO: Why We're Doing This Project

Scientists warn that most of this coastal highway — and many miles of similar roads throughout Hawaii — will soon be underwater due to rising seas, stronger storms and extreme flooding.

Giant sandbags are already heaped in front of houses teetering on the shoreline. And huge rocks and hunks of concrete line the most perilous portions, a desperate attempt to save parts of some routes while lasting solutions are contemplated.

The climate is changing, faster than ever. Imperiled infrastructure is only the most apparent front in the Aloha State’s war against a warming planet. Similar battles are unfolding throughout the islands.

Nathan Eagle/Civil Beat

High in the mountains, freshwater supplies are at risk and endemic species face extinction. Just offshore, the coral reefs that provide billions of dollars in economic value and immeasurable cultural worth are dying as the ocean heats up and bleaching intensifies.

The future isn’t forecast to look like all the pretty postcards. But scientists and policymakers say swift action can make it less ugly than otherwise projected.

Unfortunately, time is running out to develop and implement strategies to make Hawaii more resilient. And experts say the longer it’s put off, the more it will cost to adapt and mitigate.

Global Warming Most scientists and policymakers use Celsius instead of Fahrenheit when talking about warming temperatures. Given the global nature of climate change, we’ll also be using Celsius in our stories. But here are some of the key temperature change conversions. 1 degree Celsius (1.8 Fahrenheit) 1.5 degrees Celsius (2.7 Fahrenheit) 2 degrees Celsius (3.6 Fahrenheit)

“Even the best intentions today do not appear to be fast enough for the pace of climate change,” University of Hawaii climate scientist Camilo Mora says.

“In the state of Hawaii, for instance, 2045 was set as the year to achieve 100 percent clean energy,” he said. “Yet our own studies at the University of Hawaii suggest that unprecedented climatic changes will be common in the state by the 2030s.”

To ward off the worst effects, the world’s top scientists say humans must make massive shifts in their behavior to prevent the planet from warming more than 1.5 degrees Celsius above pre-industrial levels by 2040.

The world, in essence, has a fever — a degree or two is a big deal. And if we are to avoid the worst of this malady, we need to treat it now.

Convened by the United Nations, the Intergovernmental Panel on Climate Change’s October assessment narrowed the window that humans have to fend off threats to food security, transportation, energy and more.

The group had previously forecast the most dire effects to happen when the world warmed 2 C. Humans have already caused an increase of 1 C since the 1880s.

It’s no longer the next generation’s problem; it’s ours.

The report was submitted by 91 scientists from 40 countries in response to a request from the U.N. Framework Convention on Climate Change when it adopted the Paris Agreement, the 2015 global accord to tackle climate change by significantly lowering greenhouse gas emissions and holding the average global temperature increase to well below 2 C.

Their assessment calls for reducing such pollution by 100 percent from 2010 levels by 2050. That effort included abandoning coal almost entirely by 2050 while tripling the amount of renewable energy in the current electricity mix, which is roughly 20 percent, the report says.

“The assessment indicates unprecedented policy and geopolitical challenges,” the panel wrote.

The national outlook isn’t overly optimistic under the current administration, but there are hopeful signs at the local level for reducing pollution and adapting to the effects of a changing climate.

President Donald Trump in 2017 moved to start pulling the U.S. out of the Paris accord, though a complete withdrawal isn’t possible until Nov. 4, 2020 — the day after the next presidential election. The U.S. would be the only country to do so, though Brazil’s new president has expressed similar intentions.

In the meantime, Trump has worked to increase domestic oil drilling and ramp up coal production. Despite the federal stance, numerous cities and states, including Hawaii, have committed to follow the Paris agreement and the broad consensus of the world’s top climate scientists.

Cory Lum/Civil Beat

Honolulu Mayor Kirk Caldwell and Hawaii Gov. David Ige, both Democrats, have started giving much more attention to climate change. The mayor plans to devote his entire state of the city address to the issue this year, and Ige has been pushing a broad sustainability initiative that helped him win a second term in November.

But the response will require much more than words and lofty plans, which have so often only gathered dust on government shelves.

Studies, Audits And Reports Abound

Hawaii has no shortage of climate-related studies — and studies about how to do other studies — that have done little to prepare the state for the flooded roads ahead.

An audit last year of the Hawaii 2050 Sustainability Plan, a 2008 initiative under Republican Gov. Linda Lingle, found an improved sustainability ethic in Hawaii over the past decade but a lack of implementation.

Government officials have lamented how inadequate funding has hindered their ability to provide the technical services that agencies need to do detailed climate assessments.

Cory Lum/Civil Beat

Setting money aside for future issues has not been a top priority in the Legislature, which opens its next session Wednesday. But some lawmakers think that may be changing, at least when it comes to climate change.

“I anticipate that for every session from now until the day I die, global warming is going to be a big issue,” said Sen. Karl Rhoads, outgoing chair of the Water and Land Committee.

“It’s already happening,” he said, underscoring the challenging decisions confronting politicians and citizens alike.

“How to get people to use less carbon is a huge issue, a very difficult one,” he said. “Who’s house to let fall into the water and which ones to not let fall into the water is another difficult issue. It’s going to happen. There’s just no getting around it.”

Noting how the upper end of seal level rise estimates are in the 8- to 10-foot range, Rhoads said downtown Honolulu is in danger and Ala Moana Center’s parking lot is projected to have some 2 feet of water in it.

“If you look at all the highways around Oahu, even already on the windward side, you can get hit with waves as you drive down the road,” he said. “Moving those roads back is very expensive, very controversial, because you have to condemn people’s land.”

The state has policies and data that identify the many indicators of a changing climate, the 2050 sustainability audit said, noting how 70 percent of Hawaii’s coastline is eroding, streams are drying, rainfall is decreasing and corals are bleaching.

The March audit concluded that comprehensive planning would help the state adapt, but it hasn’t happened in a meaningful way.

“Through the course of the past 10 years, the Hawaii 2050 Sustainability Plan was disregarded,” the audit said.

Warnings Have Been Consistent

Scientists have cautioned the public about a warming planet for the past century. But it’s never been so grim.

The U.S. National Climate Assessment, released in November, has an entire chapter devoted to the effects of climate change on Hawaii and other Pacific islands.

Much as the IPCC’s latest report forecast the worst effects to happen by 2040 instead of years later, the U.S. assessment last year had a similar sense of heightened urgency.

Cory Lum/Civil Beat

Victoria Keener, a researcher at the East-West Center in Honolulu and lead author of the NCA’s Hawaii and Pacific islands section, said the Aloha State, and any other place for that matter, is unprepared for the effects of climate change. But she has seen Hawaii and other states take progressive steps.

“We need to do more and we need to do it faster,” she said. “Early action is going to reduce the ultimate economic impact of adaptation and mitigation.”

Sea levels had been expected to rise up to 3.2 feet globally by 2100, but the latest projections say this could happen as soon as 2060.

“We need to do more and we need to do it faster.” — Victoria Keener, climate investigator

Studies in Hawaii show that the value of all structures and land projected to be flooded by a 3.2 foot rise in sea level amounts to more than $20 billion. That doesn’t account for the compounding effect on tourism, the state’s main economic driver, and other industries.

And it’s more than lost roads and buildings. Across the state, nearly 550 Hawaiian cultural sites would be flooded or eroded and roughly 20,000 residents would be displaced, the report says.

Some iconic Hawaiian forest birds would likely go extinct as disease-carrying mosquitoes invade their mountain habitats thanks to warmer weather. The models show that even under moderate warming, 10 of 21 existing forest bird species across the state will lose more than half their current range by 2100. Of those, six are expected to lose 90 percent or more.

Hawaii is already home to nearly one-third of the nation’s plants and animals listed as threatened or endangered.

Alana Eagle/Civil Beat

Corals are expected to bleach annually starting in 2040, making it nearly impossible for them to recover. Their death means fewer fish and less coastal protection.

It’s what scares Keener the most.

“It’s not if it’s going to happen … it’s when,” she said. “The argument is whether it’s 2030 or 2050. That’s soon.”

In Hawaii, corals currently cover about 38 percent of the ocean area around the islands. By 2050, that’s projected to drop to 11 percent and then fall to 1 percent by 2100.

That amounts to $1.3 billion per year lost in the economy in 2050, increasing to $1.9 billion by 2090, the report says.

If the world meets the Paris agreement, it would delay severe bleaching by about 11 years, saving hundreds of millions of dollars, the assessment says.

Moving Forward

Hawaii has made strides in recent years. Most notably, the state has the nation’s most ambitious renewable energy mandate — 100 percent by 2045 — and has pledged to be carbon neutral by the same date.

Improvements have been made to protect watersheds and scientists are breeding “super corals” to withstand a warmer and more acidic ocean. Nonprofits have been increasingly active, and the private sector is making changes too.

Nathan Eagle/Civil Beat

The next major focus is creating a clean transportation sector, starting with ground vehicles and then moving on to the many airplanes that residents and tourists rely on.

State and county offices and commissions have been created to coordinate the focus on climate change.

The Hawaii Climate Commission in November unanimously agreed to push the Legislature to pass a carbon tax next session, which starts later this month.

And Honolulu’s voter-created Office of Climate Change, Sustainability and Resiliency has been developing Oahu’s first Climate Action Plan. The final public scoping meetings are this week.

“The greatest uncertainty now is us.” — Sam Lemmo, Office of Conservation and Coastal Lands

An increasing number of events have increased awareness of climate change. The inaugural Hawaii Climate Conference is Monday, an all-day public affair featuring panels of experts at the East-West Center.

Sam Lemmo, administrator of the state Office of Conservation and Coastal Lands, is co-moderating a panel with University of Hawaii climate geologist Chip Fletcher on accelerating action to adapt to sea level rise.

Hawaii is already witnessing the effects of climate change that were predicted decades ago, Lemmo said.

“The greatest uncertainty now is us — whether we’re going to change our behavior, whether we’re going to cut emissions,” he said.

Editor’s Note: This year, we’re putting an intense spotlight on climate change — how it’s affecting Hawaii now and what the future may look like for all of us in the islands. We’re calling our project Hawaii 2040 because that’s when the most recent studies say we’ll feel the worst effects of climate change. That’s much sooner than scientists originally thought. This year, we’re putting an intense spotlight on climate change — how it’s affecting Hawaii now and what the future may look like for all of us in the islands. We’re calling our project Hawaii 2040 because that’s when the most recent studies say we’ll feel the worst effects of climate change. That’s much sooner than scientists originally thought. Now the big question is — what are we going to do about it. How can we all change our behavior to help out? What new policies can our political leaders put in place to change things fast enough to matter? How will we adapt? Over the coming year, we want to bring you — our readers — inside the discussion in a very up close and personal way. Besides an ongoing series of stories, video, podcasts and other multimedia reports, we want you to join us in figuring out potential solutions. We’ll be visiting communities and neighborhoods throughout Oahu to talk about how these issues are affecting you personally and what you think should be done. Together we can make our voices heard.

Tell us how you’re being affected by our changing climate. What do you think should be done?