Australian scientist Hugh Possingham will walk the hallowed ground of Washington DC's National Mall on Saturday, a venue where Martin Luther King Jr delivered his I Have A Dream speech and 1995's Million Man March was staged.
Professor Possingham is taking part in the March for Science, one of many rallies held in the US, Australia and across the world as part of Earth Day.
The march comes as governments across the world cut funding to science, including at the nearby White House where US President Donald Trump is slashing programs and gutting the Environmental Protection Agency.
"Anybody who thinks science is useful and likes it hopefully will come," Professor Possingham, chief scientist at Virginia-headquartered The Nature Conservancy, a co-sponsor of the march, told AAP.
"It is a celebration of how important science is."
Professor Possingham said cuts to government science programs can make impacts that last for decades.
"If you start defunding science in countries like Australia and the US you might not recover for 10 or 20 years," he said.
"The most important message is just making it clear to the public how important science is maintaining healthy air, keeping water quality, protecting the big wilderness areas that inspire people and bring them enjoyment."
Professor Possingham said The Nature Conservancy is "very much pro science, not anti anybody" and march organisers have promoted the events as bipartisan.
"In Australia one couldn't help but notice in the last five or so years, particularly the CSIRO, has had a tough time," Professor Possingham said.
"I have worked with CSIRO scientists in wildlife conservation for decades and I'm well aware of how important those organisations have been to the prosperity of Australia, land management, soils, marine fisheries, forests."
Marches are planned in Sydney, Melbourne, Brisbane, Cairns, Canberra, Hobart, Perth, Townsville, Launceston and Newcastle.
