On Sept. 21, people of all ages will gather in Manhattan for the massive history-making People's Climate March. Others will attend countless related events around the globe. Though the hundreds of thousands attending this march will speak in many tongues, our message will be the same: We demand bold action on climate change. Now.

This demand isn't coming from nowhere. For those who call themselves baby boomers and the children of that generation, this is about continuing to build on the lessons learned over the last several decades. From smoke detectors to safety gates, infant car seats to child-proof caps, no generation has gone to greater lengths to ensure children’s safety than those born between 1946 and 1964.

Baby boomers approached parenthood armed to the teeth with flame-retardant clothing, baby monitors, safety latches and window locks.

Little did we know, as we baby-proofed our homes, that the real danger lay elsewhere, in the rapidly warming world we were creating through our overconsumption of goods and the fossil fuels required to produce them.

We know it now — and our failure to address climate change is the primary moral issue of our time.

The children of boomers have reaped considerable benefits from their parents' health and safety concerns. By any measure – the organic foods they have grown up eating, the pure water they drink, the clean air they breathe, the embrace of exercise – have given them the opportunity to live healthier lives.

Francesca Eastwood and Fracnes FisherBut none of that matters if the world inherited from boomer parents is rife with heat-related illnesses, infectious diseases, droughts and floods. The simple truth is that we will eat, breathe, and live the consequences of the world we are given. And unless something is done to limit carbon emissions, our basic human right will be denied: the right to live, work, and play in a safe and healthy environment, and to raise our children so that they may do the same.

The Peoples Climate March comes two days before world leaders meet at United Nations headquarters in New York City to begin considering an ambitious agreement to dramatically reduce global warming pollution. The U.N. Climate Leaders Summit is the perfect time for citizens of the world to flex their collective political muscle in a massive display of resolve.

Two people — a mother and a daughter who wish to speak with one voice — write this letter. We are united in our determination to take responsibility for the fate of our families and our planet. We stand for intergenerational justice and the search for real solutions to the problem of rising emissions, temperatures and seas.

We need action. Continued inaction all but guarantees that the world inherited from baby boomer parents will be a hellish one marked by political instability, famine, drought, a world of depleted resources, deadly heat waves and emergent disease.

The baby boomer generation was the generation that couldn't conceive of letting their children go for a ride around the block without their bike helmets. Now it seems shocking that the next generation could be the ones to turn their backs on kids and the prospect of a frightening future. This can be prevented and this change can begin when hundreds of thousands take to the streets of New York as part of the Peoples Climate March.

Frances Fisher and Francesca Eastwood are lifetime environmentalists dedicated to preserving a world where future generations can experience the same advantages we all enjoy today. Francesca is the daughter of Clint Eastwood, and her mother, Frances, is the star of "Resurrection" on ABC.

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