"I cannot say anything but thanks to him for his work, for the work of his foundation and the people who work with him," Prince Albert tells PEOPLE
Credit: Martin Bureau/AP

The royals are going green!

Monaco’s Prince Albert prides himself on being a keen environmentalist, but he credits Britain’s Prince Charles with being the trailblazer.

Albert, 57, who with wife Princess Charlene, 37, took center stage on Sunday as they joined thousands of demonstrators for the World Climate march in Monaco, tells PEOPLE Charles was “way ahead of the curve” on the issue.

The royal parents are giving twins Prince Jacques and Princess Gabriella (who turn 1 on December 10) a head start on the important cause as well. The family of four dressed down for the event, with the wide-eyed twins participating in the march from their double stroller.

And as world leaders head to Paris for the COP21 climate change summit, it s Charles, 68, who issued a rallying cry to delegates to consider his grandchildren – Prince George and Princess Charlotte – and other kids around the world.

“I can only urge you to think of your grandchildren, as I think of mine, and of those billions of people without a voice; those for whom hope is the rarest of sensations; those for whom a secure life is a distant prospect,” he said in a keynote speech on Monday as they begin two weeks of deliberations.

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Over the weekend, Albert paid tribute to Charles’ pioneering role as an environmentally concerned royal, exclusively telling PEOPLE, “He started people thinking. Certainly for me he was an example of leadership.”

Having previously praised Charles (and Norway’s Prince Haakon) for their environmental leadership, Albert continued, “Before I started implementing any actions, Prince Charles had already expressed a vision of sustainability what it is and how we can adjust out lives, our neighborhoods, our architecture.”

“Charles’ work on behalf of awareness, not only of sustainability but on other areas – like deforestation and alternate energy – was way ahead of the curve.

“He’s been a great advocate of a different view. One, everyone should have concerning sustainability. I cannot say anything but thanks to him for his work, for the work of his foundation and the people who work with him.”

Albert’s praise came as Charles warned in Paris, “On an increasingly crowded planet, humanity faces many threats – but none is greater than climate change. It magnifies every hazard and tension of our existence.

“It threatens our ability to feed ourselves; to remain healthy and safe from extreme weather; to manage the natural resources that support our economies, and to avert the humanitarian disaster of mass migration and increasing conflict.”

He urged action not “procrastination” and said that to “avoid catastrophe we must restrict climate change to less than two degrees, which requires a dramatic reduction in carbon emissions,” and added, “The whole of nature cries out at our mistreatment of her. If the planet were a patient, we would have treated her long ago.”