For years, when river conservationist Andrew Fahlund visited congressional offices to talk about droughts and floods, he would spend time discussing the intricate details of water runoff or the effects of changing precipitation levels. Now, with global warming the pre-eminent environmental issue, those conversations have taken on added gravity.

“Suddenly, droughts and floods take on a different tone and dimension when you think about global warming,” said Fahlund, vice president for conservation at American Rivers. “The issue enters every single conversation with folks on the Hill, and it didn’t used to do that.”

The causes and consequences of climate change are so broad that they touch nearly every other environmental issue — from air pollution to drought prevention, from coral bleaching to species extinction. Heeding this new calculus, environmental groups of all kinds have rushed to connect their issues to climate change in the public’s mind.

“It has improved the environment for environment issues overall,” said Rodger Schlickeisen, president of Defenders of Wildlife. “The community is unanimous that it is our No. 1 priority.”

The worry, though, is that global warming could crowd out other environmental concerns. Some groups fear that the intense political debate surrounding global warming will force smaller, unaffiliated groups and their issues to the sidelines until solutions are found to reduce greenhouse gas emissions and improved energy efficiency becomes the norm.

“If others can hide behind issues like global warming, they’ll use it as an excuse not to save the other issues,” said Patrick Rose, executive director of the Save the Manatee Club in Florida.

Mounting scientific evidence, some severe weather patterns and a wave of recent publicity, much of it generated by former Vice President Al Gore, have made it nearly impossible for anyone to ignore global warming.

In a Gallup Poll in March, 41 percent of respondents said they worried about global warming a great deal.

“Global warming is the elephant in the room,” said D.J. Schubert, a wildlife biologist for the Animal Welfare Institute, a 56-year-old organization that seeks to protect animals and their habitats. “It overrides everything.”

That has reordered the environmental agenda in Washington, prompting think tanks and interest groups to load up on experts who can articulate the perils of climate change.

For example, Manik Roy is an environmental policy expert who has spent most of his career documenting the dangers of toxins in the air. But three years ago he changed course and became director of congressional affairs for the Pew Center on Global Climate Change, which analyzes and keeps policy makers informed about the issue.

“I realized that if I was going to tell my kids and grandkids in 30, 40 years that I worked on environmental issues,” Roy said, “I was going to have to tell them I worked on climate change.”

Environmental groups have started to tailor their messages to global warming, both because a changing climate will affect the entire environment and because global warming is an attention getter, a platform for other issues.

The Alaska Wilderness League, for instance, was founded in 1993 to protect natural areas of the state, such as the oil-rich Arctic National Wildlife Refuge, from development. The group, which has an annual budget of just $3 million, now has recognized global warming as a broader threat to Alaska’s wildlands. It held a rally in March on the U.S. Capitol grounds to push for climate-change legislation.

“All environments are being impacted by global warming,” said Becky Wynne, the group’s communications director. “And it has provided for more opportunities for us to work together more collaboratively on issues across the board.”

American Forests, whose Global ReLeaf program has planted more than 25 million trees since 1988, revamped its platform this year to encourage people to plant trees as a way to slow global warming.

“It’s the first year we’re really emphasizing, or maybe overemphasizing, the global warming aspect of it,” said Deborah Gangloff, the group’s executive director. “We’ve seen a lot of interest from our corporate sponsors who really want to reduce the carbon footprint.”

Business’ growing interest in environmental issues in general and particularly in global warming also has provided a financial boost for groups pursuing green agendas. Kevin Knobloch, president of the Union of Concerned Scientists, said new streams of money are becoming available to environmental groups working together for climate change.

“There are more private foundations and major donors who are stepping up to invest in fighting global warming,” he said. “They are insisting that the organizations that are working on climate change work tightly together.”

Wells Fargo and Co., for instance, contributed $454,000 in grants to six environmental organizations — the first such commitment from the California bank. Although only some of the groups are directly tied to global warming, Stephanie Rico, Wells Fargo’s communications consultant on environmental affairs, said there has been pressure from shareholders to “go green.”

The League of Conservation Voters has launched a new global warming campaign and has experienced a steady increase in fundraising, said Tony Massaro, senior vice president for political affairs and public education.

“If you look at everybody’s direct mails and fundraising, there is a strong emphasis on what they are doing on global warming,” Massaro said. “The mere fact that everyone keeps . . . linking the specific issue to the general issue helps fundraising.”

The global warming debate has “driven a lot of other people’s agendas because that’s where the big money is,” said Tyson Slocum, director of Public Citizen’s energy program. “If you want to try and get funding for things, tying it into climate change will help you get money.”

There still remain those smaller groups, such as the manatee club, that plan to fight for their causes independent of the climate-change fever. But it won’t be easy, they say, because concern for global warming has become fashionable.

“People are jumping on a bandwagon,” said Rose, who has worked on endangered-species issues for 30 years. “They got their green stamp and wear their green badge, and other issues won’t get the attention they really need.”

Clean Air Watch president Frank O’Donnell, who has campaigned for years against air pollution, says he does not dispute the current focus on global warming. “Unfortunately,” he said, “it may mean that bad decisions will be allowed to stand because the media and Congress are so focused on global warming that regular air pollution issues are under the radar.”

The challenge for Democratic congressional leaders will be to address global warming along with other environmental issues they have accused Republicans of neglecting, such as improving fuel-efficiency standards and promoting the development of more alternative sources of energy.

“There’s no question that we are giving a tremendous amount of time in the committee to global warming,” said Sen. Barbara Boxer of California, who chairs the Environment and Public Works Committee. “But we are not forgetting about the rollbacks the administration has undertaken in other areas,” she said. “We are all over it. We are all over these other issues.”

In general, environmental groups are optimistic that growing concern about global warming will increase public awareness of and political interest in the environment.

Ed Hopkins, director of the environmental quality program at the Sierra Club, said congressional Democrats probably will not forget about other environmental topics despite the political frenzy around climate change.

“Congress will address global warming, and there will be time for other issues,” Hopkins said. “I’m not concerned that there haven’t been five hearings on superfund.”

Dan Cronin, communications director for Environmental Defense, said the wave of interest in curtailing climate change could broaden the audience for other messages from environmentalists. He likened it to organizing a music festival: Most people come to hear the headliners, but they might discover a new band in the process.

“Here’s one issue you came for, but here’s how we take that same kind of approach for another issue,” Cronin said. “[Global warming] is a very hot issue, but it’s obviously not the only issue.”

Technological solutions, CQ Weekly, p. 1180; greenhouse gas regulation, p. 1020; Gore campaign, p. 906.