But Mr. Resnick, who described himself as a moderate who currently leans Democratic, said he did not see the donation as political. He said he and his wife were committing money to protect future generations — including their own children and grandchildren — and because they had seen the devastating impact of climate change in their own business, growing fruits and nuts.

“No one likes to deal with something that is unpleasant if they can kick it down the road,” Mr. Resnick said. But “no experts are saying take your time. It’s happening now.”

The money will be used to build a research center and to support a broad range of projects. Among them are attempts to sequester carbon from the atmosphere and store it in the ocean; capture and reuse rainfall; make plants more resistant to drought; and create plastics that are easier to recycle, according to Thomas F. Rosenbaum, president of Caltech.

Mr. and Mrs. Resnick have been active philanthropists in California’s Central Valley, especially in providing aid to the families of their employees. They have founded charter schools and health clinics, distributed college scholarships and given to cultural institutions.

But the Resnicks’ business practices have sometimes come under fire from environmental activists.

The bottled water industry is not considered sustainable given the plastic waste it produces and the energy used to ship water long distances across the world , often to consumers who have access to free, safe water just by turning on a tap.