SAN FRANCISCO: Stephen Schneider, a Stanford University scientist who served on the international research panel on global warming that shared the 2007 Nobel Prize with former Vice President Al Gore, has died. He was 65.

Schneider died of an apparent heart attack Monday while on a flight from Stockholm to London, Stanford officials said.

Schneider studied climate change for decades and wrote a number of books charting its effects on wildlife and ecosystems in the United States, and later chronicled its effect on the nation's politics and policy. He advised every presidential administration from Nixon to Obama.

"A prolific researcher and author, co-founder of the journal Climatic Change, and a wonderful communicator, his contributions to the advancement of climate science will be sorely missed," Gore said in a statement.

Schneider was an influential, and at times combative, public voice in the debate over climate change, and appeared on news and science television programs, wrote articles and blogged.

As a co-author of the Intergovernmental Panel on Climate Change reports that earned a share of the Nobel, Schneider defended the panel's work when it came under attack from critics after some unsettling errors were discovered, including how fast Himalayan glaciers are expected to melt.

The errors were made in a subsection of the world's most authoritative report on global warming, and were found to be insignifcant to its overall findings that glaciers are melting faster than ever.

"Steve, more than anything, whether you agreed with him or not, forced us to confront this real possibility of climate change," Jeff Koseff, Schneider's colleague at Stanford's Woods Institute for the Environment, said in a statement.

In recent years Schneider fought a rare form of leukemia, a battle he chronicled in a 2005 book, "The Patient from Hell." That fight helped put into context his work on climate change, helping him to see hope in often gloomy work.

Schneider is survived by his wife, Stanford University biologist Terry Root, with whom he jointly won the 2003 National Conservation Achievement Award from the National Wildlife Federation.

Arrangements for a memorial service are pending.