Geologist Chip Fletcher loves what he does so much it’s hard to know where the work ends and hobbies begin.

He loves being around the ocean and shoreline — he lives near Kailua Beach with his family — so if the research puts him offshore with students to collect core samples, he’ll never complain.

Fletcher, 57, now an associate dean at the University of Hawaii School of Ocean and Earth Science and Technology, finds a lot of his research and other duties have him more office-bound these days. He misses being up close and personal as often with two geological processes within his expertise: erosion and sea-level rise.

But those topics remain top of mind, now more than ever. He’s written a book on the topic: "Climate Change: What the Science Tells Us," which was released about a year ago.

And recent episodes with coastal erosion on Oahu have caught his attention. They may be related to an eddy of ocean water passing through the islands, he said. But even if the temporary cause is true, Fletcher said, it provides a preview to what rising sea levels could do in the long term.

Technology can be a help in maintaining valuable beaches, he said.

"So for places like Waikiki and Kaanapali, where the benefit-cost ratio supports it, you can spend millions of dollars and put sand on the beach on a regular basis, every couple of years or every 10 years, as a maintenance exercise, the same way that you paint your house every few years, or you fill potholes in the road," he said.

But in other cases, it would be better to avoid the hardware solution such as seawalls, which tend to make erosion even worse on neighboring properties, such as what’s happened in Kihei. He wants his grandchildren (there’s one here already) to be able to enjoy Kailua Beach, which so far lacks seawalls.

His rhetorical questions: "Are we going to allow the first seawall on Kailua Beach? Are we going to allow the first step toward the demise of Kailua Beach? Will the community speak up?"

QUESTION: Don’t many people assume we can engineer things to prevent beach erosion?

ANSWER: Right. Well, there’s this ever-abiding faith in engineering and human wit. In some respects, we can. But in other respects, you can’t engineer an ecosystem. There are some aspects of the coastal ecosystem where simply getting out of the way is the best thing to do.

So if sea level’s rising, and the beach sits at the edge of the ocean, if that beach can’t move, it’s going to drown. It’s very simple. And that beach can’t move if you put a wall behind it, a seawall. And so beaches drown in place. They also drown because waves slap against the seawall and actually scour the sand and send it offshore.

And because our de facto coastal management approach for over 100 years — and I’m speaking about in Hawaii and actually around the world — has been to build a wall when erosion threatens the land, to build a seawall, we’ve lost a lot of beaches in Hawaii.

One reason why there’s been so much erosion and a strong need for seawalls is because sea level has been rising for over a century in Hawaii — not rapidly, but persistently. Eventually that will catch up to you. Slowly, persistently rising sea levels and where we build our houses are eventually going to collide.

And, unfortunately, when we first created our laws about how close you could build to the ocean, we didn’t give enough of the buffer. We basically said, 40 feet, the statewide setback is 40 feet.

Q: What should it have been?

A: It should have been 150 feet. It should have always been on the other side of the highway.

Q: So no beachfront?

A: Yeah, basically. … There are towns in Australia that did this right. They have a good 100-meter walk, 100-yard walk to the beach. That’s the closest from any road. So that’s 300 feet. That’s the right way to do it.

Q: Too late for us.

A: It’s too late for us in many areas, most areas.

Q: What else did we do wrong?

A: Well, the setback is too short and it’s one-size-fits-all. So if you have a beach that is eroding at 2 feet per year and you have another beach that’s actually not eroding at all, it’s still a 40-foot setback. So at 2 feet per year erosion, the 40-foot setback is going to be gone in 20 years. So one-size-fits-all doesn’t recognize that erosion is place-based. … Right from the start we should have gotten data: What’s the rate of erosion, and let’s scale our setback based on that. …

Now the setback on Maui is 50 times the annual rate of erosion. And on Kauai it’s 75 times the annual rate of erosion. Why 75? Because that’s the average lifetime of a wood-frame house in the United States. … Plus a buffer, plus 20 feet.

So that makes more sense, except the rate of erosion they’re basing this on is averaged over the past century. But sea-level rise is accelerating, so past rates of erosion are no predictor of future erosion hazards. So we need to continue to update our erosion data. And we need to model the projected impact of sea-level rise in the future.

Q: Are these recent regulation changes?

A: Maui did this about 10 years ago, Kauai did it about four years ago, plus or minus.

Q: And we have done nothing on this island.

A: Nothing on this island, right. It’s much more crowded here. When you change the setback it can lead to a very energetic conversation between managers of the shoreline and owners of coastal lands, because they get afraid that their land is going to be taken from them, and that the flexibility to do with their land what they want will be taken from them. …

There is this idea floating around us … of "legacy beaches." Are we going to leave a legacy to our grandchildren? Will we leave any beaches? Can we as a community define some beaches where the primary goal of management is to keep that beach in the future? … The primary goal is to not have any activity that can damage that beach.

Q: Do you think climate change has gone too far for humans to reverse the process, or is our action crucial now?

A: I’m glad you didn’t position the two ends of the spectrum as, "Does it exist?" Because we’re way beyond that. There’s no such thing as a debate about whether or not climate change exists; it’s a fake debate. You can find it on Fox News, but that’s one of the few places you can find it.

I think that climate change is an extremely dangerous, deadly process that’s taking place, and that if we continue to ignore it, it’s at the peril of our ecosystem and our communities to the point where food shortages, drought, shortages in drinking water, increasingly hazardous billion-dollar weather disasters — all of these things which we’re now seeing take place in front of us every year.

The biggest drought in United States history happened in the summer of 2012. Heat waves in Europe in 2003 killed over 70,000 people. A heat wave in Russia in 2009 killed 50,000 people. These are very real events that didn’t used to occur.

Q: But what can be done about it? Have we let it go too far?

A: No. It’s never too late to respond to it, and it’s extremely important that we do respond to climate change. And thank goodness President Obama has seen that he can take some important steps without the permission of Congress.

Q: For example, what steps do you think were important?

A: He’s required that automobile mileage, by 2020, that there be doubling of the efficiency of automobiles. And this past year, the carbon emissions of the United States were the lowest they’ve been in 20 years, and much of that was due to improved automobile efficiency. So we should continue pushing in that direction. … And the federal government’s going to require new efficiency levels for appliances. …

Over half of electricity generation is from renewable sources in the United States. Now, much of that is backed by subsidies from the federal government. But all energy resources, when they first got started, were backed by government subsidies. And, in fact, the petroleum companies are still backed by federal subsidies. We need to take those federal subsidies that are basically tax breaks that are aimed at the petroleum sector, and we need to turn them on the renewable energy sector. …

Q: Obama’s taken criticism for not being as aggressive as some would like. The Keystone pipeline issue, for example.

A: Well, he’s still waiting to say the

final word on that. And the rumor in the hallway is he’s going to deny the permit for the Keystone pipeline.

Although, the Keystone pipeline is more symbolic than real in terms of producing a large carbon footprint in the United States. But symbolism matters, especially in politics. …

He’s got the EPA (Environmental Protection Agency) working on new rules for power plants, such that it’s going to severely restrict coal-fired power plants, which is a good thing. Coal-fired power plants are incredibly toxic, not only for global warming reasons but just for human health reasons. … I think our Kahe Point is coal-fired. Oil and coal. We get a lot of coal that’s shipped in here.

Q: Are there measurable improvements in the carbon footprint, or is it symbolic?

A: No, it’s not symbolic. The hard discussion is with India and China. India and China point to the United States and say, "You got yours; why are you asking us not to get ours? You’re asking us to stop our industrialization, … not to achieve that quality of life in order to cut our carbon emissions." Now the United States can show that they have cut our carbon emissions.

We still need to pass a congressional law, something like the Waxman-Markey bill that went down in flames in 2009. But that’s ready to be reinvigorated, if we ever turn Congress around into realizing that climate change is a real threat. … This is going to take a long time.