Why have three of the four members of Hawaii’s congressional delegation not signed on to U.S. Rep. Alexandria Ocasio-Cortez’s Green New Deal (GND), House Resolution 109? It now has 90 total co-sponsors, up from the original 68; companion resolution Senate Resolution 59 has 11 total co-sponsors.

Among Hawaii’s delegation, only U.S. Sen. Mazie Hirono is a co-sponsor. It’s appalling that U.S. Sen. Brian Schatz, U.S. Rep. Tulsi Gabbard and U.S. Rep. Ed Case have not added their names.

The GND may be the boldest, most sweeping proposal since its namesake, President Franklin D. Roosevelt’s New Deal of the 1930s. It doesn’t spell out details — but it could change American society profoundly. From the right, it draws howls of “radical” and the obligatory “slippery slope to socialism.”

It is radical, absolutely; long overdue; and very welcome. Climate change is radical, too. And it requires a response that’s radical, profound, extreme, revolutionary.

At a December TEDx Talk, 16-year-old climate activist Greta Thunberg admonished, “We can’t save the world by playing by the rules. Because the rules have to be changed. Everything needs to change. And it has to start today.”

The GND answers Thunberg. Will it slow climate change? So far, nothing else has.

As associate editor Robinson Meyer recently wrote in The Atlantic: “It throws all of American government and industry behind an attempt to make renewable energy cheap.”

H.R. 109 also contains passages like, “upgrading all existing buildings in the United States,” “providing resources, training, and high-quality education … to all people of the United States,” and “guaranteeing a job with a family- sustaining wage, adequate family and medical leave, paid vacations, and retirement security to all people of the United States.”

Big ideas, to be sure. And why not big ideas? When did a big idea last come out of Washington, D.C.?

But the GND’s biggest ideas are about fighting climate change. Because if we can barely live on our planet, the other big ideas matter little.

Our organization, 350Hawaii, very strongly supports the GND — not because it is perfect, but because it accomplishes major things we need badly:

>> It brings renewed attention to the urgent need for climate change action as nothing has since the Paris Agreement, now over 3 years old and showing few effects.

>> It lets the U.S. show leadership on climate- change action. And it’s a model for every country.

>> It provides a rallying point for everyone to learn about climate change, get involved, and advocate for action. Last month, a Business Insider poll found that more than 80 percent of Americans supported almost all of its key ideas — 80 percent! People are finally aware that we’re in crisis. They’re at last hungry for action and have seen little else to rally behind.

>> After decades of increasingly dire but ever-understated warnings by obscure scientific bodies, the GND bluntly calls for the extreme measures that, at this point, we must take.

>> It offers a vision for solutions to myriad long-standing problems, including an atrophied American manufacturing workforce and numerous social inequities.

The GND is vague, as it must be at this point. The details will be worked out in many laws. What we need now is the solidarity and resolve that the GND offers. Right now, as it builds momentum, our entire Hawaii delegation needs to contribute to that momentum. If you agree, call them.

It may feel too soon to commit, but if decision-makers don’t act now, when will they? And if not the new U.S. House majority, then who? This is the best chance we’ve ever had to save ourselves.

“I don’t want you to be hopeful,” chided Thunberg. “I want you to panic. I want you to feel the fear I feel every day and then I want you to act.” That is the voice of Generation Z. Our delegation owes it to Greta Thunberg, and to all of us, to listen. And to sign onto the GND now.

Brodie Lockard is founder of the Hawaii chapter of 350.org, a grassroots environmental organization.