An island community should know the danger of indifference to the environment, all the more so when Earth Day rolls around every year on April 22. The actions — or inactions — resulting from that indifference will simply circle around and come back to haunt the human inhabitants.

People of Hawaii do know that, at least on some level. But it seems to require repercussions that hit them directly.

And that has begun to happen, with a vengeance.

To begin with, climate change has rolled into Hawaii consciousness with the ferocity of increasingly intense storms, as have struck communities around the world. Sea levels have been rising, and erosion has been in plain evidence on coastal properties statewide.

King tides have exacerbated the problem, and stormy seas swamp the coastal highways with alarming regularity. That’s one reason why the long-awaited inland realignment of Maui’s Honoapiilani Highway was pushed to completion. It opens to traffic Monday morning.

Even under normal conditions, the rising seas have had erosive effects on beaches that are becoming impossible to ignore. Palm trees fringing hotels suddenly are standing in the sand, their roots exposed. Waves erasing the beach fronting homes and churches, and undercutting the stability of shoreline roads.

It’s hardly questioned anymore that the activities of humans have played a significant role in global warming, or that their addiction to fossil fuels contributed to the greenhouse gases in the atmosphere, raising temperatures. Getting Hawaii off its dependence on petroleum has been at the heart of environmental policy here for years, the topic resurfacing again on Friday.

Tied to the global observances, the daylong Earth Day Energy Summit at Washington Place explored reasons why Hawaii can, and should, pick up the pace toward its green energy goals. It was convened by the nonprofit Elemental Excelerator, which commissioned a new report on the issue.

That report, titled “Hawaii’s Path to a Clean Energy Economy” (transcendingoil.com), was unveiled at the event. Its themes are familiar to Hawaii residents: The expense of importing oil filters through the economy and boosts the cost of living, in addition to the effect of carbon emissions on the environment.

But the assertion is that Hawaii could achieve up to 84 percent clean energy, and generate 3,500 additional well-paying jobs, by 2030. This would advance the state’s Hawaii Clean Energy Initiative targets, which would require 40 percent conversion by 2030 and 100 percent clean energy by 2045.

The report’s myriad proposals include creating an open-data environment for the electric grid to encourage innovation for a more efficient distributed-energy system. There is also the suggestion to institute a carbon tax, essentially putting a price on the use of fossil fuels that will incentivize cleaner alternatives.

This doesn’t have to be dismissed as blue-sky idealism. In fact, the tide could be turning. House Bill 1986, which is awaiting appointment of Senate conference committee members, would establish a carbon offset program.

This program would allow for the sale of credits to offset the carbon emissions of polluters. California has raised billions of dollars, according to the legislation, and the aim is for Hawaii to use its revenues for various projects mitigating climate change effects.

That’s an encouraging prospect, and one that deserves a Hawaii-based launch.

It won’t be an easy lift, though: For all its green-energy advantages, Hawaii typically makes its changes in a halting fashion.

For example: A mandate that new homes be built with solar water heaters has been on the books for years, but many projects have pushed ahead using liquid natural gas heaters instead, due to a loophole in the law. HB 1864 is the latest effort to close that loophole, an action that is overdue.

The pathway to environmental balance is not going to be a smooth ride. Plagued by some transportation and market disincentives, even something as simple as recycling has struggled to catch on fully. Oahu shoppers can’t seem to remember their reusable bags at the market, and foam containers are still the packaging of choice.

And if Honolulu is to surmount challenges en route to its green future, officials should confront them honestly. Example: The city initially gave a rosy review to its recent trial of electric buses — until riders gave the full picture. The vehicles still lack the full power needed to tackle inclines, witnesses said.

“The days of political infighting and delay tactics are over,” said Marti Townsend, Sierra Club of Hawaii director, in response to an email query about the road ahead.

“There is a wave vision, innovation and courage to try in young people these days that gives me real hope that we are making the changes that need to be made,” Townsend said.

Earth Day may be just the occasion to acknowledge the difficulty of change, but to embrace it with that optimistic spirit.