Having predicted an overcrowded, hungry, polluted and generally bleak turning of the century for a resource-poor planet, the Council on Environmental Quality and the State Department yesterday suggested a way for the United States to change the future: spend a lot more on research and planning and pay a lot more attention in the White House.

"We've done the easy part: raising the issues and making the challenge," CEQ Chairman Gus Speth told a news conference. "Coordinated development of policy is absolutely essential."

Proposals in the 250-page study, titled "Global Future: Time to Act," are "a body of good ideas for the first round" of international efforts to deal with problems that CEQ and the State Department raised six months ago in their "Global 2000 Report" to the president, Speth said. He estimated that implementing the recommendations would cost $1 billion to $1.5 billion annually.

The proposals focus on institutional changes and specific programs, recommending a White House coordinating unit of about 30 persons and a separate information-gathering and computer modeling center braced with "action-forcing devices" like budget review procedures, periodic presidential messages and blue-ribbon study commissions. A separate public-private institute would enlist the business community.

Speth said a copy of the study had been sent to President-elect Ronald Reagan but that he had not yet responded.Reminded that Reagan has said the earth could comfortably support 20 billion people, Speth replied, "A lot of things get said in a campaign. I anticipate a good response."

The world population is now about 4.5 billion but it is growing at 80 million persons a year, which the study regards as the key problem of the future, leading to pressures on every resource and to certain political instability. With U.S. interests so obviously at stake, the report called for a doubling of spending on research and aid in family planning to other nations, along with more international aid in child care.

"Sustained commitment to development assistance is critical," the report said, noting that U.S. annual foreign aid at $5.1 billion is now 15th largest among industrialized nations in percentage of gross national product, just ahead of Austria and Italy. Although some nations contribute the United Nations goal of 0.7 percent of GNP, Speth stopped short of endorsing that figure, which for the United States would be $18.2 billion.

The study recommended expansion of food development aid, of efforts to teach conservation techniques for land and water use, and of instruction in pest control.A short-term voluntary technical assistance program using private sector volunteers could help promote energy conservation, and the United States should pledge to meet 20 percent of its energy needs from renewable sources by the year 2000, the report said.

Water wars are likely as population growth continues, so conflict areas should be identified now and steps taken to keep the peace, the study said. There should be conferences and task forces to study international nuclear waste disposal, carbon dioxide emissions, forest destruction and growth of deserts, while potential losses to the international gene pool from those problems ought to be inventoried, the report continued.

The study's suggestions came from a task force of 19 government agencies which Speth said showed unprecedented cooperation in putting it together.The recommendations have not been coordinated with each other or with those of similar groups like the Brandt Commission -- which reported last year to the United Nations on Third World problems -- and do not represent any kind of government position or action plan, he added.

Mary Elizabeth Hoinkes, deputy assistant secretary for environment at the State Department, who presented the report with Speth, said the goal of the report is "to stimulate actions at the local level internationally. We realize we can't begin to solve these problems on our own."